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FGX XR6 cruise control issues after gear ratio change


SASV
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We've got an FGX XR6 6 speed manual ute (non turbo) with a close ratio 5th and 6th gear fitted and since the ratio change, cruise control won't work in 5th and 6th gear and only works in 3rd and 4th. We can't remedy the problem with SCT or HP Tuners software however it's been suggested that PCMtech software likely will access the areas possibly the VID block we need to alter.

Does anyone know if there are in fact areas in the PCMtec software accessing gear ratio parameters in relation to cruise control? There appears to be a factory preset of speed vs RPM and with the higher RPM of a lower ratio 5th and 6th gear showing effects like a slipping clutch prevents the cruise control from setting.                                                   

 

 

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11 hours ago, SASV said:

We've got an FGX XR6 6 speed manual ute (non turbo) with a close ratio 5th and 6th gear fitted and since the ratio change, cruise control won't work in 5th and 6th gear and only works in 3rd and 4th. We can't remedy the problem with SCT or HP Tuners software however it's been suggested that PCMtech software likely will access the areas possibly the VID block we need to alter.

Does anyone know if there are in fact areas in the PCMtec software accessing gear ratio parameters in relation to cruise control? There appears to be a factory preset of speed vs RPM and with the higher RPM of a lower ratio 5th and 6th gear showing effects like a slipping clutch prevents the cruise control from setting.                                                   

As Apoc mentioned above these are the parameters you will want to modify for the gear ratios.

image.thumb.png.fb6a1f90ddb255323b648d1c42fe9aa9.png

Afaik HPTuners don't have the minimum/maximum ratio mapped which I believe is used for determining an error which is what will be shutting the cruise control down. The min/max are for determining clutch slip. You may find this is causing the throttle to pull under big loads as well as there is clutch slip protection built into the PCM as well which will pull the throttle if the OSS doesn't match the rpm for an extended period of time.

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2 minutes ago, apoc said:

I assume it measures wheel speed vs rpm on the 6speed manual box? Unless there's an OSS sensor in the gearbox on these, which I didn't know about.

Yes it infers OSS via wheel speed from the ABS module. So if your diff ratio or tyre size is out it will also stop cruise control from working. I think only the very early BA's with no ABS run an actual OSS sensor, though I've never actually seen myself, others will know better.

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Thanks guys, that explains it with a minimum and maximum threshold for each gear ratio is the reason cruise still works in 3rd and 4th gear and has shut down with the revised ratios on 5th and 6th.

Just to confirm, will the professional system access this or do we need the workshop version?

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My 5 speed manual Ba XT ute had the speed sensor in the gearbox + no abs or wheel speed sensors.

It was the same VSS that was in my mates AU manual, its possibly a generic VSS for the older models. The newer models pull the speedo from the abs/wheel sensors afaik.

When i put a turbo 5 speed box in it i needed to use the na box rear extension housing to retain the mount for it, as the turbos all use the abs sensors for speed.

none of the 6 speed manual boxes come with a mount for the speed sensor afaik. 

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1 hour ago, SASV said:

Thanks guys, that explains it with a minimum and maximum threshold for each gear ratio is the reason cruise still works in 3rd and 4th gear and has shut down with the revised ratios on 5th and 6th.

Just to confirm, will the professional system access this or do we need the workshop version?

Pro has access to these variables.

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2 hours ago, BeerTurbo said:

The newer models pull the speedo from the abs/wheel sensors

Yes. The FGX Tremec TR6060  with an XR6 doesn't have a speed sensor. The only electrics to the gearbox is the reverse lock out solenoid and the reverse light switch.

Thanks again guys, we'll have a go at fixing this cruise control issue with PCMtec software early next week and I'll let you know how we go.

 

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  • 5 months later...
On 9/27/2018 at 2:20 PM, Roland@pcmtec said:

As Apoc mentioned above these are the parameters you will want to modify for the gear ratios.

image.thumb.png.fb6a1f90ddb255323b648d1c42fe9aa9.png

Afaik HPTuners don't have the minimum/maximum ratio mapped which I believe is used for determining an error which is what will be shutting the cruise control down. The min/max are for determining clutch slip. You may find this is causing the throttle to pull under big loads as well as there is clutch slip protection built into the PCM as well which will pull the throttle if the OSS doesn't match the rpm for an extended period of time.

If i have changed my ratio to 3.9 in a manual FG sedan, what do i need to set these parameters to? 

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On 4/1/2019 at 10:08 AM, Roland@pcmtec said:

If you have the VID block enabled and a car other than FG Mk2 the VID block will override some of these values afaik.

If it doesn't work, how do I disable VID or is that not possible? 

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