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Hi guys, does anyone know if the VT BCM can store any codes in ite memory? a friend of mine has this VT that has an intermittent fault where all of the bcm functions stop working (power windows, central locking, wont start) since he cleaned some of the earth terminals it hasnt happened again but hes just curious, if it does, should he go to holden and get the tech 2 to pull out the codes. hteres not much point doing that if the bcm doesnt store them anyway.

any help will be much appreciated
Jayme

Jayme,
There are DTC's stored in the BCM.
The Tech 2 can also be used to activate a number of tests on components it controls (central locking, indicators, wipers, low fan, etc).
This can be used to systematically work through the system to identify what is causing the problem.
Unfortunately the DTC's are not defined enough to do this.

yoda69

This is more than likely the BCM lockup, it is caused by a spike through the key reader circuit, there is a diode harness available to stop it, otherwise reset the BCM by pulling the fuse if it happens, its a common fault.
ill see if i have a diagram for the diode wiring, its really simple to setup
Rob

haha i like your avitar rob its great

cheers rob, ive got the wiring diagram for it, just waiting on the fault to happen again so we can start fault finding.

you have the wiring for the diode harness?
i cant find my copy, its really simple, just a diode to drop any spike in the key reader circuit to ground, it is fitted at the key reader & grounded on the existing point on the ignition lock housing

hopefully this isn't the beginning of a BCM meltdown like what happened to my wife's Monte Carlo. It just started acting wacko. That is actually when I first became interested in car electronics. I ended up getting a cheap elm332 to talk to it and learned quite abit about talking to her car. I actually got to the point where I attempted to mimic the radio talking back .

As for pulling codes from the BCM if you can talk to it low level is make sure you are using physical addressing and use mode 19 requests for the data. With an ELM use this:
at sh 6c 40 f1
19 d2 ff 00

This will get you the real and pending trouble codes in the BCM (assuming the BCM is module $40 because it could be from $40 to $c7). As for translating the info you get back it is in the ELM doc's.