VZ Body Control Module

[mcsquirt]

Guys,

I've been having what may be a very intermittent Body Control Module fault or wiring problem...

Symptoms:

(Radio shuts off & on repeatedly - sometimes climate control goes off and occasionally the whole instrument panel goes out too!)

This condition may last from a few seconds to maybe 30 seconds - sometimes you lose the backlighting and the instrument
panel goes dark and all the gauges drop to zero as well?)

Only occurs when the car is relatively cold (usually within 10 minutes of an initial startup)
Noticed on winter days it appears more frequently....

Fault may also materialise with sudden acceleration or braking / rough road - If it goes off while Braking hard you may also get an ABS
fault alarm..with the chimes - Interesting it does not log this condition as a fault code?

Once the car has warmed up (or you have the heater on) it doesn't happen again ....


This situation (lots of devices all going off together - cold fault / intermittent etc) has me thinking
its in the electronics not the wiring ---I may have a dry joint or failing component in the BCM (Level 3 - LUX)???

Does anyone have a schematic for the VZ - LUX (Calais V8) BCM?

I want to log some of the BCM pinouts to see if I can trap what's happening....

Thanks,
McSquirt

[Big_Valven]

The ABS fault warning without throwing a code would suggest low voltage either from the alternator or to the cluster / dash / BCM themselves.

Are you familiar with Diagnostic Mode on the trip computer? I am fairly sure it's MODE and ^, hold them down when you start the engine, you can then cycle through a heap of 'hidden' parameters. Find the battery voltage one and keep an eye on it.

It won't help if the whole cluster drops out, but may help keep an eye on things sometimes.

A friend's VY did the same thing, albeit not dropping out completely, and it was the regulator on his alternator.

[mcsquirt]

I am familiar with the diagnostic mode and the instrument cluster tests OK.. I've checked the battery voltage with and without the alternator running. All the voltages and the ripple is quite small. However the alternator is now about 7 years old and has 150,000km on it (its the original unit) so far nothing on it has been touched.

That's why I wanted to see a schematic and log some of the BCM pinouts on the BCM... to see if whatever changes when the intermittent condition is active.

I've been slowly working through all the BCM functions such as "auto off" for the headlights / and Accessory Power to check that all the relays on
the BCM are functioning... This involves ignition off / door open / door close - then check all the functions like raer demist / lights / stereo etc (its all in the BCM)...
the bit that makes me think its in the BCM is all the systems impacted during a fault have connections into the BCM or have alternate controls through the BCM.

Thanks,
Mcsquirt

[Peter B - CV8]

There are a couple of relays within the wiring that affect charging. Might be one of them playing up ???

[mcsquirt]

The latest updates:

It's not the Alternator!
Its' not the Earths - One on the Body near the ABS / Other on Block near Drivers side engine mount (Checked and cleaned both of them!).

The Voltages and AC ripple are all fine.. Tested with no load and full load!

Now tracing the main wiring back from the Battery through the power distribution module...

You know the bit that is making this really tough!!!

You can no longer get the Factory Service Manuals and Wiring Diagrams from Holden...
The Original Part Number for the VZ Service Manual (VZ102006) is NO LONGER AVAILABLE
as a spare part and there is NO ALTERNATIVE SUPPLIER......

A POX ON HOLDEN FOR THIS ONE....... Well I'm gonna bug your dealers to copy the bastard (on-line manual) a page at a time....
Let's see who gets sick of this first!.... You guys are gonna wish you'd given me a manual after I waste a couple
of thousand of your dealers dollars.... (Oh just to be clear - with no prospect of Holden ever getting paid)....

[mcsquirt]

Well great news: The VY & VZ Service and Maintenance Manuals (Factory Manuals) fro the MY05, MY06 models are available.

Today I picked my CD-ROM up from SUTTONS PARTS in LIDCOMBE (Sydney)...

The retail on this SMI Disk is around $500 (Which is half the cost of the old blue books for a typical VR or VS --- A full set of those
will cost you over $1000 assuming you can still get all the volumes)

It still has the part number VZ102006.

It is still a special order through Holden Parts back to Infomedia (the company who produces the disk).

Just so everyone knows it work with anything from Windows 98 onwards up to Windows 7 (32 Bit)

I'm told it does not work on Windows 7 (64Bit Edition)