micro-controller using CAN bus data for ancillary control

[2X044]

Sharing this semi-complete project now that it is up and running. Before getting into it, I owe thanks to @Lukeyson and @jakka351, they don't know me but I relied heavily on the information they shared and to the team at ForScan it would have been a lot harder/impossible without there work! Beers are on me.

I completed a manual conversion on my BA Mk2 XR6T, for some reason, the PCM would not ground the reverse lockout wire. I understand that the PCM is supposed to ground the pin when the car is travelling less than 7km/h and the clutch is depressed. I read that most people use the brake light circuit to ground the wire but I didn't like this idea.

The data I required is available via the CAN bus so I bought a micro-controller with a native CAN bus interface and put together a prototype board that does the following:

• Listens on the CAN bus for the vehicle speed.
• When the vehicle speed is below 5km/h, once per second, sends a query to the PCM asking the status of the clutch pedal.
• When the vehicle speed and clutch status are correct, pulls the reverse lockout wire to ground using a MOSFET (and turn on an LED to show me it's working).

Here is the proto-board:

Here it is hidden in the console with all the wires coming in the back:

Now that it is all working, my mind is running on all the possibilities having a programmable micro-controller hooked into the cars CAN-bus with a bunch of analog and digital ins/outs so I am currently designing a PCB that breaks out a lot more of the micro-controllers pins. My design brings out the following:

• 3x digital outputs via MOSFETs that will ground up to 2A each
• 1x 0-12V analog output (op-amp)
• 1x 0-10k variable resistance (to ground)
• 5x analog inputs (with voltage dividers so that it is 12V tolerant).

More inputs/outputs are possible in the future but I would change to surface-mount components.

My ideas on things that I can do with it are:

• Progressive shift-light using a string of 8xWS2812 LEDs
• Slow down the fuel-pump via PWM and a solid state relay when off-boost
• Spoof the F6 oil pressure sensor signal to the PCM (don't think this one is needed with PCMtec)
• Factor style PID boost control (for the NA + T crowd)
• Yaw control using the input from an IMU (needs a lot more thought and big cajones while tuning)

I'll post up code and designs on github shortly and update this with a link then.

I hope this inspires someone, I will try to answer any questions however this isn't a beginners project.

Edited September 7, 2022 by 2X044
typo

[Roland@pcmtec]

My wish list

Cheap closed loop boost control. This puts and end to the shortage of turbo PCMs. 

Intercept the oil temp and pull it high eg 255c on failure modes like low fuel pressure or other conditions that rely on external sensors not present on the factory pcm. 

You could wire in low oil/fuel pressure analog inputs with pre configured ranges for sensors you include in the kit. 

Lean out detection via wideband when load > 1.5 etc 

Make it all configurable easily via simple dials, no usb, no laptop. Super simple. Sell the full kit, fittings, loom that is the right length for each model, make everything truely plug and play. 

Package it up with IP rated case, obtain power from an existing plug (eg the oil/cht temp sender) then a sandwitch plate for obd/can and make it a 20 minute job to install and wire up. No crimping, no wiring. Use off the shelf oil pressure and fuel pressure sensors . 

I can send you the broadcast packets to sniff to get this data at 16ms intervals for ba/bf/fg. 

We would happily push this product on our facebook page/website at no cost if it was robust, reliable and didn't have stock issues. 

This would effectively implement all the most important parts of an after market pcm at a low cost. People would make it almost a mandatory add on for a stock pcm tune. 

[Lukeyson]

<Crawls out of the woodwork, tips hat....>

[2X044]

You've got my mind churning now! Some interesting "wishes" there.

I'd been thinking about how to trip "limp home" mode through spoofing a sensor but hadn't thought of the oil temp. I'd been thinking about intercepting throttle position signals but if the PCM will respond to a change in the oil temp that would no doubt be easier. If anyone has a surplus oil temp sensor (BA if there are differences) kicking around send it my way and I'll work out how to intercept and mimic it. I suspect either the analog voltage outputs or the variable resistor that I've included on the PCB will do the trick I just need to work out ranges, slopes and offsets.

The closed loop boost control is an interesting challenge, including making it fail to safe should anything happen to the micro-controller. I'll probably need to talk to you about how it is implemented by the factory PCM to try to match it and make sure I have all the inputs needed.

Other sensors should be straight forward, again ranges, slopes and offsets will be needed to ensure the PCB is designed correctly as the micro-controller analog inputs are natively only 3.3V tolerant. I've got a SAAS oil pressure sensor and an autometer fuel pressure sensor kicking around so can start with them.

By far the hardest part will be the packaging, QC, etc. to make it a commercial offering. I'm sure there will be some special "gotcha's" in the implementation, but that is half the fun.

I'd given a little thought to how configuration could be made easy but hadn't got to simple dials. Depending on what is possible with the Tactrix, my first thought was that the configuration could be sent over the CAN bus via unused identifiers (extended?). It may even be possible to make it seamless for PCMtec users.

This is only a hobby for me, I'll keep you informed of progress but it may be slow. My turbocharger is fubar at the moment so that will need my immediate attention.

[hjtrbo]

@2X044 Random tangent question. What PCB design software are you using?

For your interconnects to an IP rated enclosure, Deutsch DT series pcb header connectors are covid stock affected. AMP AT series is a similar offering which are still well stocked. Hammond Manufacturing make some really nice rugged IP rated enclosures that are priced very reasonable. 

[2X044]

@hjtrboI am using KiCAD for the pcb design. Thanks for the tips regarding connectors. The proto boards are using phoenix contact screw connectors which are still available on digikey (for now).

[hjtrbo]

Ok, cool. It looks nice the board it designs. Hopefully this might give you an idea on enclosures. This is a Hammond Manufacturing 1455J1201 extruded aluminium enclosure and the connectors are AMP AT13 series. @Puffwagon

Edited September 8, 2022 by hjtrbo

[2X044]

That design looks good, I think I'm independently keeping several Aliexpress stores afloat and have a number of "automotive" enclosures and connectors. I bought the enclosure that I'm using from Altronics as I wanted to be able to see the LEDs inside.

How do you cut the holes in the sliding lid?

[hjtrbo]

Hahaha, it gets like that sometimes! I've been there in the past buying up bulk.

For inside the cabin your box will be okie dokie. But it is nice to splash out a little more and go for the OEM look on certain projects once in a while. 

I've got a small milling machine with a DRO that should get the job done. Doesn't give a water jet finish but good enough with a bit of hand finishing.   

[Bill]

I've got a dead BF turbo PCM in the shed that come with a ute I bought. It had been opened up by the previous owner in a rough way after it wouldn't power up. If the board is of use to anyone to compare against a stock NA BF ZF6/6sp manual PCM to develop an add on boost controller for NA PCM's or see what's required to modify a na PCM, I'm happy to post it to them.

[Whiteford]

Additional functionality that would be useful for the racing guys, picking up wheel speed and correcting for different size wheels and tyres front to rear.

I get asked for this quite a bit and have no solution available to offer.

When cars are fitted with radials for drag days, this induces a limp home condition and makes the car undrivable.

[jakka351]

19 hours ago, hjtrbo said:

Hahaha, it gets like that sometimes! I've been there in the past buying up bulk.

For inside the cabin your box will be okie dokie. But it is nice to splash out a little more and go for the OEM look on certain projects once in a while. 

I've got a small milling machine with a DRO that should get the job done. Doesn't give a water jet finish but good enough with a bit of hand finishing.   

Pop in inside a Bluetooth Phone Module casing. moy bueno

[2X044]

13 hours ago, Bill said:

I've got a dead BF turbo PCM in the shed that come with a ute I bought. It had been opened up by the previous owner in a rough way after it wouldn't power up. If the board is of use to anyone to compare against a stock NA BF ZF6/6sp manual PCM to develop an add on boost controller for NA PCM's or see what's required to modify a na PCM, I'm happy to post it to them.

Yes please, I'll PM you.

6 hours ago, Whiteford said:

Additional functionality that would be useful for the racing guys, picking up wheel speed and correcting for different size wheels and tyres front to rear.

I get asked for this quite a bit and have no solution available to offer.

When cars are fitted with radials for drag days, this induces a limp home condition and makes the car undrivable.

I can think of two (maybe three) ways of doing this, not sure which would be best but all would be "invasive" to the wiring of the car and not a 20 min job. The challenge is that with the ABS controller connected it will be publishing the wheel speed data on the CAN bus. You either need to trick it to broadcast the "normal" info or disconnect it and then pretend to be it (with potential for all sorts of issues).

5 hours ago, jakka351 said:

Pop in inside a Bluetooth Phone Module casing. moy bueno

I've ordered one of these from Aliexpress... Way too big for a final system but should be good for a plug and play prototype while leaving an OBD2 port available for ForScan/PCMtec.

[hjtrbo]

10 hours ago, 2X044 said:

I've ordered one of these from Aliexpress... Way too big for a final system but should be good for a plug and play prototype while leaving an OBD2 port available for ForScan/PCMtec.

Yeah, that's definitely a sizeable chunk of plastic lol. Would have to leave the fuse panel cover off. I use a ribbon style splitter cable. Pushed the factory OBD port back out of it's housing in the fuse panel. Then I have the obd port of the splitter cable pushed through the fuse panel cover handle opening. Makes life just that little more convenient. 

OBD II 16 Pin OBD Cable Male To Female Y Splitter Extension Cable (ozsmartthings.com.au) 

 

[2X044]

2 hours ago, hjtrbo said:

Yeah, that's definitely a sizeable chunk of plastic lol. Would have to leave the fuse panel cover off. I use a ribbon style splitter cable. Pushed the factory OBD port back out of it's housing in the fuse panel. Then I have the obd port of the splitter cable pushed through the fuse panel cover handle opening. Makes life just that little more convenient. 

OBD II 16 Pin OBD Cable Male To Female Y Splitter Extension Cable (ozsmartthings.com.au) 

 

Better than my bodge splitter.

[Roland@pcmtec]

18 hours ago, 2X044 said:

I can think of two (maybe three) ways of doing this, not sure which would be best but all would be "invasive" to the wiring of the car and not a 20 min job. The challenge is that with the ABS controller connected it will be publishing the wheel speed data on the CAN bus. You either need to trick it to broadcast the "normal" info or disconnect it and then pretend to be it (with potential for all sorts of issues).

Alternatively you could intercept the wheel speed sensors themselves, or even just replace them with something that is configurable so you can adjust the front/rear ratio.

[jakka351]

On 9/9/2022 at 4:58 AM, 2X044 said:

I can think of two (maybe three) ways of doing this, not sure which would be best but all would be "invasive" to the wiring of the car and not a 20 min job. The challenge is that with the ABS controller connected it will be publishing the wheel speed data on the CAN bus. You either need to trick it to broadcast the "normal" info or disconnect it and then pretend to be it (with potential for all sorts of issues). 

@WhitefordIf this is just the rear tyres - you could wire up a switch that causes an open circuit in both Rear Wheel Speed Sensors -> ABS module wiring -> CAN Data now broadcast from the ABS for the rear wheels becomes 0xFF(invalid) and an ABS fault is triggered, you lose ABS, TCS and DSC and the cluster doesnt shut up, but you are not in LIMP mode and can race car all day, hit the switch and back to normal. Yes / No ?

Take it a step further and open up the ABS module, get into the firmware and write some software that can edit all the thousands of parameters that are probably in there. Then you can "tune" the antilock braking system. 

[Roland@pcmtec]

You can just pull the ABS fuse if it's an auto the car and disable the fault code 

Obviously you lose ABS functionality if you do this though. 

[Whiteford]

Seeking a non-invasive solution

[Roland@pcmtec]

I'm sure the ABS module can be read/written using the standard UDS protocols which are publicly available. It would not be rocket science to look for the MSG IDs, trace these back and find the wheel slip % and start modifying things. The code may not even be checksummed.

@jakka351 why don't you give it a crack?

[jakka351]

Bosch ABS Boot Mode (nefariousmotorsports.com). Its on my list. 

[jakka351]

12 hours ago, Whiteford said:

Seeking a non-invasive solution

ABS M5 Kit | Bosch Motorsport (bosch-motorsport.com) ask these guys 

 

Do you have an old ABS module Anthony?

Edited September 12, 2022 by jakka351
added question

[jakka351]

CCA Development Environment (bosch-motorsport.com)

 

"We provide the option to run software code on our ECUs that has been developed by the customer. This code is run in the customer code area (CCA) and is protected against access of anyone else. Within ECUs and VCUs, this feature can be run in parallel to all further functionality.

We deliver it with a full environment for Matlab/Simulink, a compiled Bosch model as library and a package of Matlab/Simulink interfaces to all I/Os."

 

 

[2X044]

On 9/7/2022 at 6:55 PM, Roland@pcmtec said:

Intercept the oil temp and pull it high eg 255c on failure modes like low fuel pressure or other conditions that rely on external sensors not present on the factory pcm.

I've been doing some reading and making sure the next PCB can support this requirement. I found this information regarding the EOT sensor:

Unless we can change the behaviour of the PCM on receiving an "out of range" or "abnormal" reading, the EOT will be ignored and the desired outcome of protecting the engine will not be achieved. Am I reading this correctly?

Edited September 13, 2022 by 2X044
errors...

[jakka351]

4 hours ago, 2X044 said:

I've been doing some reading and making sure the next PCB can support this requirement. I found this information regarding the EOT sensor:

Unless we can change the behaviour of the PCM on receiving an "out of range" or "abnormal" reading, the EOT will be ignored and the desired outcome of protecting the engine will not be achieved. Am I reading this correctly?

 

It is just saying if the sensor output seems unlikely to be true the PCMs failure strategy is to ignore the sensor and replace that value with that of the cylinder head temp sensor value - keeping the engine runnning pretty much as it was before the failure - so trying to fuzz this signal to the pcm wont work - as it will just ignore it. You probably want to cause a condition where the pcm sees 140-160 degrees celcius at the CHT - as it will start shutting down cylinders and dumping fuel in to try cool it down. Roland  has mentioned it in these forums before i'm sure, all the parameters are in the software, you can set the failsafe point temps as they rise and fall.

[Roland@pcmtec]

Pulling it high above whatever the cht limp mode is will trigger a limp mode. 

You can also do a crude anti lag this way as well by pulling IAT high. 

Its simple and has been done for years by piggy back computers. 

[Roland@pcmtec]

On 9/12/2022 at 10:34 PM, jakka351 said:

ABS M5 Kit | Bosch Motorsport (bosch-motorsport.com) ask these guys 

 

Do you have an old ABS module Anthony?

Not exactly cheap. Can buy an aftermarket PCM for the price of a Bosch Motorsport configurable ABS module. They are designed for 300k track cars. 

[Puffwagon]

On 9/12/2022 at 10:14 AM, Whiteford said:

Seeking a non-invasive solution

Find a set of front wheels that match the back.

[jakka351]

21 hours ago, Roland@pcmtec said:

Not exactly cheap. Can buy an aftermarket PCM for the price of a Bosch Motorsport configurable ABS module. They are designed for 300k track cars. 

Mate I have a 5.4, it is a 300k track car. Almost. 

 

[jakka351]

On 9/12/2022 at 1:56 PM, Roland@pcmtec said:

I'm sure the ABS module can be read/written using the standard UDS protocols which are publicly available. It would not be rocket science to look for the MSG IDs, trace these back and find the wheel slip % and start modifying things. The code may not even be checksummed.

@jakka351 why don't you give it a crack?

 

On 9/12/2022 at 10:44 AM, Whiteford said:

Seeking a non-invasive solution

There is a diagnostic routine that can disable the safety software - it may be possible to actually do this with minimal effort, just need to test it in practice. Test it in the red herring mobile.

[Roland@pcmtec]

On 10/3/2022 at 7:07 PM, jakka351 said:

There is a diagnostic routine that can disable the safety software - it may be possible to actually do this with minimal effort, just need to test it in practice. Test it in the red herring mobile.

Anymore information on what the "Safety software" is? There are a lot of failsafes in the ABS module that you wouldn't want to disable. Make sure you test it somewhere safe.

[jakka351]

50 minutes ago, Roland@pcmtec said:

Anymore information on what the "Safety software" is? There are a lot of failsafes in the ABS module that you wouldn't want to disable. Make sure you test it somewhere safe.

at this stage unsure, its something that may be better tested with modules on a bench and a simulator rather than in a vehicle.

[Roland@pcmtec]

4 hours ago, jakka351 said:

at this stage unsure, its something that may be better tested with modules on a bench and a simulator rather than in a vehicle.

Gravel carpark with a functional handbrake at low speed is usually pretty safe. 

[2X044]

Doing skids in gravel car parks takes me back to my youth...

Finally got the progressive shift light working though not installed properly, I've halved the rpm that the lights are coming on so I don't have to rev the berries out of the car for the demo. First light will come on at 3000rpm and they all go red at 6000. Interesting to see how much lag is in the tacho.

https://vimeo.com/757148325

Edited October 5, 2022 by 2X044
broken link

[hjtrbo]

Broadly related to the topic. 

Home built injector dead time tester. 

pcmhacking.net - View topic - Injector Dead Time Testing

[Kirby@PCMTec]

Ah cool to see someone finally working on this!

@2X044, not sure what toolchain you are using for the feather. But if you are looking for something a bit cheaper/flexible with integrated CAN check out the ESP-32. This has a SJA1000 on silicon, so the addition of a cheap tranciever will have you up and running in no time. The added benefit is you can use the inbuilt wi-fi to host a simple website for configuration. Being able to easily change config without special tools or complexity is the real important part of the solution.

If you don't want to use IDF, the Arduino shim layer is probably sufficient for the level of complexity you are after.

You should be able to implement the failsafe with a minimal amount of hardware.
You would need one 0-5V ADC channel for a 100psi fuel pressure sensor, one resistance based input for the existing CHT.
A single resistance output to emulate the signal back to the PCM (depend on the full scale resistance of the OEM CHT - or if you can determine the internal pullup in the PCM modify the curve to however you need).

 

auF1361 is the calibration curve for the standard CHT in ADC counts. (10 bit)

auF1544 is the set point which will illuminate the warning light (engine hot)

auF1870 is the set point (degF) to start dumping in fuel for cooling e.g. CHT CRITICAL. (warning light should start flashing)

auF11960 is the timer after which CHT CRITICAL is entered that the engine will shutdown with a CEL (never tested this)

auF10259 is the set point above auF1870 where a sensor failure is determined  (e.g. non plausible). So you can't just peg the sensor to say 0v without potentially tripping this value.

 

Basically you want to emulate an input to the EOT pin which provides a temperature above auF1870 and below auF1870+auF10259 (or change these to suitable values).

 

Then the logic in your device is:

if fuel pressure < threshold, for some time

then set CHT emulation output to some value to trigger FMEM

else 

set CHT emulation output to CHT reading input

 

Keep going, the market is totally ready for this product + whatever other features you could include.

 

[hjtrbo]

Agree. Tuner nerd has a new permanent install knock block available. 

Your device would be nice to have a minimum selector (takes the lowest value) that triggers the fault action. I.e. low meth level, meth controller fault, knock box output active, fuel pressure out of range, oil pressure out of range etc etc... where those inputs are configured a priority, with the most severe shutting down the engine, whilst the least severe could drive the rear O2 sensor input low on a flex fuel tune which would push the PCM towards a safe timing / boost / fuel map. 

[2X044]

6 hours ago, Kirby@PCMTec said:

Ah cool to see someone finally working on this!

Thanks for the input Kirby. I agree the feather is not the best choice but was a really easy choice to get started with.

I've just got the first PCBs made that still use the feather but a chip shortage issue and a slight miss on geometry got through the design. This was still just a prototype but starting to put a few more parts in place, such as reverse polarity protection and diodes on digital channels.

I've started working through a redesign using the ESP32 S3 and a CAN bus transceiver but I likely won't pull the trigger on this until I can get closer to the goal using the feather.

Regarding CHT, I was planning to be lazier than your logic description, I was planning to leave the CHT attached to the PCM to read normally unless a "fault" state is detected, at this time, I would pull the output of the CHT down either directly to ground (and therefore straight to full scale (255 degrees?)) or to ground through a resistor (to some value lower than full scale). After reading through the details of the CHT sensor, I wasn't confident I could emulate it accurately enough.

Progress is slow and my xr6t is having boost control issues presently (mechanical, not electrical) that will need to be solved before I can do any testing.

[2X044]

1 hour ago, hjtrbo said:

Agree. Tuner nerd has a new permanent install knock block available. 

Your device would be nice to have a minimum selector (takes the lowest value) that triggers the fault action. I.e. low meth level, meth controller fault, knock box output active, fuel pressure out of range, oil pressure out of range etc etc... where those inputs are configured a priority, with the most severe shutting down the engine, whilst the least severe could drive the rear O2 sensor input low on a flex fuel tune which would push the PCM towards a safe timing / boost / fuel map. 

I'm sure this would be possible, but not on my BA as BA's don't have a rear O2 sensor. Anyone want to set up a "go fund me" page to buy me a BF/FG xr6t?

[Kirby@PCMTec]

 

8 hours ago, 2X044 said:

Thanks for the input Kirby. I agree the feather is not the best choice but was a really easy choice to get started with.

I've just got the first PCBs made that still use the feather but a chip shortage issue and a slight miss on geometry got through the design. This was still just a prototype but starting to put a few more parts in place, such as reverse polarity protection and diodes on digital channels.

I've started working through a redesign using the ESP32 S3 and a CAN bus transceiver but I likely won't pull the trigger on this until I can get closer to the goal using the feather.

Regarding CHT, I was planning to be lazier than your logic description, I was planning to leave the CHT attached to the PCM to read normally unless a "fault" state is detected, at this time, I would pull the output of the CHT down either directly to ground (and therefore straight to full scale (255 degrees?)) or to ground through a resistor (to some value lower than full scale). After reading through the details of the CHT sensor, I wasn't confident I could emulate it accurately enough.

Progress is slow and my xr6t is having boost control issues presently (mechanical, not electrical) that will need to be solved before I can do any testing.

 

Using those parameters above you can really manipulate the whole setup, I wouldn't think emulation shouldn't be a problem. Likewise in your original spec:

• 1x 0-10k variable resistance (to ground)

would be a sufficient output driver to the CHT input on the PCM - because the original input is just an NTC (so ADC with some fixed pullup) you don't really need to worry about input impedance or anything - your variable resistance output could be a pretty straightforward design.

You can also adjust auF1316 to be linear or whatever curve you output, which is similar to the way we approach using the rear O2 for flex input.

 

While switching works (e.g. pull low, or via another resistor to land in the right region), you miss potentially being able to use the "three-step" warning which is set by those parameters (E.g.):

 

-Temperature Light On

-Temperature Light Flashing + Fuel Adding

-Engine shutdown (after 15s)

 

Then you could potentially determine your warning type based on input and decide how you want it to interact with the end user.

E.g.

• Fuel pressure straight away into fuel adding mode to try and prevent lean-out and shutdown in the case of a FP failure
• Warning only if you have a low meth level or meth controller fault

 

@hjtrbo's idea of manipulating the flex input is not a bad one, you could also use just "dual map" with switch input. But again this is not for BlackOak (BA) PCM's which don't have a rear-O2.

I think if someone developed this product and had a use case for adding some custom logic in CustomOS for a simple map switch based on some parameter config for a failsafe map, we would give it real consideration to add in development.

The Falcons using factory PCM's have needed something like this hardware for a long time, so we are happy to support it because it is complimentary to what PCMTec does...

[2X044]

I've spent a ridiculous amount of time in trying to find the exact parts required to make a system plug and play and am now waiting on a slow UPS boat...

Meanwhile I had the thought that the strategy that I used to convert my car to a t56 from btr may have been a t5 strategy so tried a couple of other strategies. It turns out that my hunch was correct and with the ba f6 strategy the pcm pulls the pin low and the original motivation for this thread was a mistake. No regrets  I've learned heaps and have some spare parts for other things.

Hopefully I'll have first testing of the cht spoofing done in a couple of weeks.

Still need to fix my boost issue and now have a rattle that I've concluded is the flywheel coming loose... No rest for me.

[Bill]

8 hours ago, 2X044 said:

I've spent a ridiculous amount of time in trying to find the exact parts required to make a system plug and play and am now waiting on a slow UPS boat...

Meanwhile I had the thought that the strategy that I used to convert my car to a t56 from btr may have been a t5 strategy so tried a couple of other strategies. It turns out that my hunch was correct and with the ba f6 strategy the pcm pulls the pin low and the original motivation for this thread was a mistake. No regrets  I've learned heaps and have some spare parts for other things.

I've seen the issue with the reverse lockout not working before on a conversion & until you've posted what you found, I didn't investigate it too far.
Checking HAAT3VC F6 strategy against HAANFG4 t5 XR6T strategy, the reverse lockout parameters are blank. Opening HAANFG4 on it's own & searching reverse lockout, the parameters aren't included in the strategy.

In the past, I've just compared the gear ratios of manual strategies to the F6 to determine if it's a 5 speed or 6 speed manual strategy but now know checking reverse lockout is another option. F6 6 speed open below with 5 speed in the compare.....MTX ratio helps get the cruise control working on a 6 speed conversion 

[2X044]

12 hours ago, Bill said:

I've seen the issue with the reverse lockout not working before on a conversion & until you've posted what you found, I didn't investigate it too far.
Checking HAAT3VC F6 strategy against HAANFG4 t5 XR6T strategy, the reverse lockout parameters are blank. Opening HAANFG4 on it's own & searching reverse lockout, the parameters aren't included in the strategy.

Thanks Bill, it's like you've been watching me. My car was originally HAANFHZ and HAANFG4 was one of the codes I tried as it was very close to the original without knowing if it was a T56 or T5 tune, I now have the HAAT3VC in the car and it appears to be pulling the pin low as it should.

Although I have the "Professional" license for PCMtec, I have never seen the "Workshop/Professional Development Parameters". Might be "Workshop (not) Professional". Is this correct?

 

[Bill]

9 hours ago, 2X044 said:

Thanks Bill, it's like you've been watching me. My car was originally HAANFHZ and HAANFG4 was one of the codes I tried as it was very close to the original without knowing if it was a T56 or T5 tune, I now have the HAAT3VC in the car and it appears to be pulling the pin low as it should.

Although I have the "Professional" license for PCMtec, I have never seen the "Workshop/Professional Development Parameters". Might be "Workshop (not) Professional". Is this correct?

 

Not a problem Peter, you are correct. The reverse lockout parameters are classified "Workshop/Professional Development Parameters" & are only visible to workshop customers

 

[2X044]

Got some testing done today and might have hit a snag.

I can mimic any temperature I like for the CHT. A picture I never want to see for real.

However there is monstrous amount of damping in the PCM responding to changes. Maybe 5s for it to go from 23 to 189 degrees where the change of input occurred instantaneously.

Is the damping an editable field?

[Kirby@PCMTec]

15 hours ago, 2X044 said:

Got some testing done today and might have hit a snag.

I can mimic any temperature I like for the CHT. A picture I never want to see for real.

However there is monstrous amount of damping in the PCM responding to changes. Maybe 5s for it to go from 23 to 189 degrees where the change of input occurred instantaneously.

Is the damping an editable field?

 

I think at the end of the day, if you are getting to a point where you are wanting to force a shutdown - a high temperature gauge is probably not a bad thing to snap your attention.

I will look and see if I can find out how the CHT is calculated and if there is any hysteresis term we could adjust.

[2X044]

Thanks Kirby. Thankfully I have not had the occassion where I have lost fuel or oil pressure but I would think that a system would need to react in less than a second to reduce/eliminate damage. Speaking to racers, it seems the most effective way of getting the drivers attention is an annoying buzzer which is also an option.

While I used the word damping, on further reflection a more accurate term would be low pass filtered, increasing the frequency of the filter cut-off will reduce the time to change but may cause noise issues. If hardware level filtering is being used (capacitor/resistor) there will be no way to practically change it.

There are other ways to shut down an engine that I can think of, such as interrupting the CAS, though this has EMI/RFI noise management implications. The crudest may be to just cut the ignition/coil power using a solid state relay.

[jakka351]

2 minutes ago, 2X044 said:

Thanks Kirby. Thankfully I have not had the occassion where I have lost fuel or oil pressure but I would think that a system would need to react in less than a second to reduce/eliminate damage. Speaking to racers, it seems the most effective way of getting the drivers attention is an annoying buzzer which is also an option.

While I used the word damping, on further reflection a more accurate term would be low pass filtered, increasing the frequency of the filter cut-off will reduce the time to change but may cause noise issues. If hardware level filtering is being used (capacitor/resistor) there will be no way to practically change it.

There are other ways to shut down an engine that I can think of, such as interrupting the CAS, though this has EMI/RFI noise management implications. The crudest may be to just cut the ignition/coil power using a solid state relay.

A stock engine/tune is going to go through a bunch of different different protection mechanisms before shutting down, like torque reduction, cylinder shutdown, before finally killing the engine. Could you not just wire up a relay in line with the CHT signal wire to the pcm, when your condition is met the relay activates and x amount of resistance is added/removed to/from the CHT signal wire circuit such that the CHT reads to the pcm as hot enough for immediate shutdown - there may also be plausability checking done by the PCM that could cause it to ignore such a signal and then use the 'default CHT in case of failed sensor' value.

[Puffwagon]

In the case of a complete loss of oil pressure you want an immediate engine shutdown and also a failure to restart. Immediate shutdown is the only suitable way of dealing with a complete oil pressure loss. In the case of oil pressure going low ie 10 psi, a complete throttle shut with the inability to reopen the throttle until the ignition is cycled is suitable.

For fuel related things, the only thing we are concerned about is the engine leaning out. A complete loss of fuel pressure solves itself, the engine shuts down, however should be addressed. A partial loss of fuel pressure is where things get dangerous and a suitable fail-safe for this is to close the throttle. An issue I see here is losing the FPR reference line and still having 60psi of fuel pressure, when you should have 100psi. When you return to cruising, the fuel pressure will fall below 60psi with the vacuum, so using a fuel pressure number as a dumb/ on off fail-safe wont work. While we may be able to integrate a wideband signal to activate the fail-safe at a set voltage, we still see the same issue where we can't just pick a number, due to the wideband number being suitable at decel but not at WOT. At a minimum we need a map reference as well as a wideband reference to control the fail-safe, preferably with a TPS reference to cover rapid throttle closing after a run where the fuel might cut but still have a high map value. While the fail-safe may mimic the action of lifting the throttle after a run, it is preferable to not have the vehicle enter a failure mode unnecessarily.

Preaching to the choir here but these things need to happen instantly. A flashing warning for those that are a bit slow on shutting the ignition off is something to add but not strictly necessary.

Anyhow there's a few cents

[2X044]

1 hour ago, jakka351 said:

A stock engine/tune is going to go through a bunch of different different protection mechanisms before shutting down, like torque reduction, cylinder shutdown, before finally killing the engine. Could you not just wire up a relay in line with the CHT signal wire to the pcm, when your condition is met the relay activates and x amount of resistance is added/removed to/from the CHT signal wire circuit such that the CHT reads to the pcm as hot enough for immediate shutdown - there may also be plausability checking done by the PCM that could cause it to ignore such a signal and then use the 'default CHT in case of failed sensor' value.

This is the approach that I tested, unfortuneately the logged temperature took 5+ seconds to reach its new level, so even with an instantaneous change in resistance, it doesn't look like we will have a timely response. Kirby was going to check if there is a way to hasten the system. I will check if the PCM responds rapidly even if the log shows it changes slow, but I don't like my chances.

I found that the PCM ignores a resistance that is too low (~below 100 Ohms), it also seems to ignore very high resistance. Everything in between seems to be accepted, when translated to the calculated "coolant temp" that value tops out at 122 deg C regardless of how high the CHT goes.