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View Full Version : Swapped VZ Holden 1mb PCM - Cruise Control issue



krisr
August 5th, 2012, 06:54 PM
Hey guys, I have bought a spare 1mb PCM from a VZ 5.7L SS ute which was an automatic car. The car i'm putting it into is a 6speed manual that has already been tuned using COS3 (04140003). I've read the full cal from the manual PCM and flashed it onto the spare PCM from the auto car. When I put the spare PCM into the car, it drives fine, everything works as it should, i've fixed up all the issues from the previous tuner, but I can enable the cruise control on the stalk, but it will not engage/hold speed for me. The original tuned PCM that came with the car lets cruise control work fine.

Question I have is, are automatic PCM's different to manual PCM's in pinout or anything that would stop cruise from working or is there anything in the tune that dictates cruise control behavour? Like something I may have missed when I did the full flash over the spare PCM as it came from an automatic car maybe? or is cruise control completely handled by the BCM - car is a 2005 CV8Z Monaro 5.7L. Cruise not working is not the end of the world as i'll just flash my fixed tune back over the top of the original PCM and keep the spare as a spare, but i'm just curious as i've searched endlessly through the Tune Tool and come up empty.

Cheers!
Kris

ScarabEpic22
August 5th, 2012, 07:08 PM
Did you full flash the new OS or just a cal flash?

krisr
August 5th, 2012, 07:20 PM
Did a full flash, it took quite a few minutes compared to a cal flash.

krisr
August 5th, 2012, 11:33 PM
Well that sucks, I did a full flash of my tune back to the original pcm and cruise control still doesn't work, so I guess that means something in the tune is stopping it from engaging, the bcm is playing up or the stalk is broken.

If it helps I can upload the tune?

joecar
August 6th, 2012, 07:32 AM
Yes, upload it, someone will have a look at it.

krisr
August 6th, 2012, 10:27 AM
Hey Joe, tune attached.

After doing a bit more reading it may not be the tune but it never hurts to have another set of eyeballs skim over it. I've found that my model car uses switches on the clutch pedal aswell as the brake pedal, also if a tail light globe is blown can affect it, I need to get up to 40km/hr first etc.. Will check the mechanicals and see how I go.

Cheers!

GMPX
August 6th, 2012, 10:36 AM
Was the service number on the PCM the same? There is a few different types out there for the 1Mb LS1 PCM, not all are the same.

krisr
August 6th, 2012, 10:38 AM
ahhh touche, i'll check when I get home.