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HOWTO: Engine Protection Settings


Roland@pcmtec

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From the factory the Ford Falcon comes with a huge number of FMEM (Failure Mode Engine Management) modes. These are designed to protect the engine from failure when running in severe conditions or under a sensor failure.

Some of the different protection modes from the factory are as follows:

  • Boost restricted to spring pressure on intake temperature over temp.
  • Boost restricted to spring pressure on overboost detection.
  • Engine timing reduced on knock detection
  • Engine timing reduced on high intake temperature
  • Engine timing reduced on high engine coolant temperature
  • Fuel enrichment on catalytic converter over temperature
  • Fuel enrichment on exhaust over temperature
  • Fuel enrichment on turbo over temperature
  • VCT disabled on low or high oil temperature.
  • A/C compressor shutdown on high engine coolant temperature
  • Partial injector shut off on extreme coolant or oil over temperature
  • Throttle/torque reduction on wastegate failure (overboost)
  • Throttle/torque reduction extreme coolant or oil over temperature
  • Boost restriction on extreme coolant or oil over temperature
  • Complete engine shutdown on extreme oil over temperature
  • MIL lamp indicator on any of the above failure modes.

The following tables (not all) are related to the above failure mode protection settings.

auF16463 (wastegate open loop FG) sets the duty cycle to 0.2 on over temp.

image.png.6f86196f22f08470f78b425c4f2494ae.png

auF0303 and auF0302 (FG) are the enable/disable setpoints for fuel enrichment to protect a turbocharger.

image.png.e626e9f9a236f910f347c91a10b29cd3.png

auF16615 control the fuel enrichment for exhaust over temp.

image.png.e060c0cb3e614ea097786e95fd3299fb.png

auF0196 will enable catalytic converter temperature protection

auF0197 is the setpoint upon which to enable fuel enrichment to protect a catalytic converter

image.png.d882882548d94de860ba751b49e1bd99.png

Knock retard is controlled by various settings under "Knock Sensor" in the navigator.

auF0278 / auF0277 CHT (cylinder head) Overtemp refers to the oil over temperature protection enable setpoint.

image.png.9b2dc777561fededebf7c43f4902a167.png

auF1870 is the critical coolant temperature upon which the engine will be shutdown

image.png.70f417f0822ed5070f8f7c91f9d001cb.png

If you don't wish to shut the engine down but instead make it run on half the cylinders you can set auF1613 to a number less than 6

image.png.1f8838a5d29df45a1ffffe0d147e1fa2.png

For more information about the CHT shutdown settings see this post here:

 

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Yes. The CHT is carry over from when the logic used to refer to cylinder head temperature. Some vehicles inferred CHT from oil temp however in the Falcons it means engine oil temperature

auF1594 is also oil temp and limits throttle to limit RPM however it needs to be enabled first. To enable auF1594 the oil temperature must be > than the value found in auF0277 which is 275F by default.

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A lot of people disable them entirely, I recommend just extending the window so it doesn't occur during normal conditions. As if you get collapsed muffler, melted vac line on the wastegate actuator or coolant leak you definitely want the FMEM action kicking in.

Personally I would lower the engine shutdown setting for oil over temp as well. Torque limiting should occur at 130 °C however if you have disabled the ETC clip settings (some people do  this without realising) the torque reduction may not actually do anything until it reaches 200 °C

Apparently modern synthetic oils still provide lubrication above 200 °C however I would bet other components start to fail before then.

You would only see these kind of temps with a pump failure or doing a sustained burnout but it could definitely happen.

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  • 1 year later...
On 3/1/2019 at 8:01 AM, Romulus said:

Perfect, and explains why AFR's plummet to low 10's at WOT after a while. These couple of parameters hadn't been adjusted.

is there  a table to view how much fuel is added for cat/turbo/exhaust overtemp protection? 

just fixed the wideband and noticed last night while launching from a standstill the afrs were perfect 1-2 gears, then in 3rd gear it would hold 0.05 lambada units more than commanded. Happened twice, so might need to pull out the logger. 

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20 hours ago, BeerTurbo said:

is there  a table to view how much fuel is added for cat/turbo/exhaust overtemp protection? 

just fixed the wideband and noticed last night while launching from a standstill the afrs were perfect 1-2 gears, then in 3rd gear it would hold 0.05 lambada units more than commanded. Happened twice, so might need to pull out the logger. 

Yes but it is not really that simple.

auF2071

This table controls the temperature decrease due to increase in lambda. There are a few limits but it will go as low as 0.75 lambda to control temperature. The simple method to tell if this is the case is to simply switch off the exhaust/cat protections when tuning then turn them back on afterwards to check.

image.png.38e2880bf2d58932cf1348a86416d07f.png

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  • 6 months later...
13 minutes ago, TommyH said:

Is there a possibility of shutdown on reduced fuel pressure??

Barra PCM has no input for fuel pressure.

I've had some fuel pressure issues recently and thought about just installing a under 50psi alarm using a pressure switch. 

Mechanically you could use a hobs switch in line with the boost controller that may deactivate the solenoid if its under a preset fuel pressure.... but that will bring you down to gate pressure not engine protection. 

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2 hours ago, TommyH said:

Is there a possibility of shutdown on reduced fuel pressure??

There is no fuel pressure sensor from the factory, however you could easily wire an aftermarket fuel pressure sensor into a falling edge timer relay and pull the cylinder head temp circuit high to trigger a shutdown if you wanted. Cost you about $20 for the relays and wiring. Farnell sell TOFF relays. 

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  • 2 weeks later...

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