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)

[mcsquirt]

Earths - Earths - Ground Points and Ground Connections....

Think I found the root cause of the Radio / Cluster / ABS intermittent faults.

... All the Wiring Harness for the Cockpit / Front Body all terminate
at a single Ground Point (A white 6 Way connector) tucked in behind the Battery on the fender inside the
Engine Bay (its X157 in the wiring diagrams or Ground Point - GP2.....

I found a small amount of corrosion / rust on the post and the nut. The highest resistance was a few Ohms
and the lowest about 0.3 Ohms - Sounds small but when you are sinking currents up to 40Amps the Voltage Drop
can be the full 12V which will cause all kinds of weird intermittent faults.


Took the connector all apart cleaned all the pins with a wire brush. Resistance is now 0.1 Ohm or less.

So far no hint of a problem..,.. Having the factory manuals & wiring diagrams makes all the difference....

[lord_hydrax]

Hows your car going now? Has this issue gone since the last thing you did here?

I just started having the EXACT same issue descirbed on my VZ SS Commodore over the past week... about to start going through what you've done!

[mcsquirt]

Guys,


When the Alternators on the VZ's get to high mileage (150,000km) something starts to go odd
with the electrics. (Sympton becomes visible under hard braking / hard acceleration / when cold / when pulling a full electrical load).

Another piece to the puzzle..... (There are two different Alternators used on the VZ's).... You need to identify which one you have fitted...

I replaced my old alternator a few weeks ago with a brand new unit and a lot of that very weird (intermittent electrical faults)stuff went away.

Just a note to the guys with the VZ's.... There appears to be two different kinds of alternators used in the VZ's (one which is the same as the VY - the pins on the plug to the engine loom
look like this - big fat plug (I I) on the later models and the pins are much smaller look like this (- -)

Have a careful look at the Alternator loom plug before you purchase a replacement alternator.

The other change is that on the later models (- -) Holden / Mitsubishi is now supplying Alternators fitted with an overrun clutch (I believe these are the same units that run with the LS2's).
I also noticed that the idler pulley isn't as "twitchy" at low RPMs' with the new (overrun clutch) Alternator.

The unit I am running is the (- -) unit with the overrun clutch (I have an LS1 engine built 08 - 2005) but the spec on this alternator is supposedly LS2, so far, done a bit over 5,000km since fitted and everything stable!
Genuine Mitsubishi Electric Corp part number is A003TG1581 (140 Amp Model)

The cost on e-bay for a Mitsubishi Unit was around $200

[mcsquirt]

The problem was definitely the Alternator....

Seems that the voltage regulation is all done by the Computer (based on what load it senses
it drives the Alternator to output more current.... If that feedback get upset it goes nuts!....

Changed the Alternator around November last year (Now 6 months later) - Been running fine ever since - No problems.....

Never seen anything like this fault before.....
(Weird / Cold Sensitive / Very Intermittent / Multiple Systems & Instruments involved)

[mcsquirt]

Well its a year later..... The Alternator is working fine.... The Earths are all good and I have had a year of stable operation.....

Sadly, the Starter motor is playing up (Slow to wind over sometimes have to try 3 or 4 times to get it to kick over)....
Got the genuine Starter Motor - Not Fitted yet!

Water Pump has failed (Leaking main Bearing) - Got the Parts and fixed that one

Noticed my Cooling fans were not working fully (Got a temperature about two needle widths above 1/4)
Turns out I had lost the small fan completely- Both Windings in the small fan failed and only one winding in the Big Fan was working!

This is a nasty fault..... If you get the same scenario on a HOT DAY and you lose the last winding this will toast your engine....
If you a moment check you are getting BOTH FANS on when you trip the A/C and they should kick in BEFORE the Temp gauge gets
to 1/4 (About two needle width below 1/4)

Have now replaced both FANS.... (All Good!)

[mcsquirt]

Well the starter Motor has been replaced...

Alternator still good (No weird intermittent electrical faults) YIPPPEEEE!

Got myself the VZ Binnacle (about to fit that).

Still got one intermittent "ticky" lifter. Only ticks about 1500kms afetr an Oil change
when engine is hot and after a long idle (~8-10mins)

Just moving to try a Nulon 15W-50 Full Synthetic Oil to see how that goes.

[steve000]

Hey mate,

Thanks for keeping us up to date.

I too have the new BCM/PCM controlled alternator instead of the standard type.
You mentioned you got the one with the clutch installed, no issues but correct voltages still?

Steve

[mcsquirt]

Steve,

The Mitsubishi Alternator I fitted is the same one they used in the VE's. Voltages all good!

The best part about the alternator with the overrun clutch is it takes all the twitching (at low RPM's) out of the main belt tensioner too.

Its all still going great!

[Woodchukka]

Never heard of a alternator clutch overrun pulley. Had a search on it then. Not going to run out and buy one however an interesting concept.

[IJ.]

Never heard of a alternator clutch overrun pulley. Had a search on it then. Not going to run out and buy one however an interesting concept.

VZ 6.0L had em stock ;)

[Micks]

VZ 6.0L had em stock ;)

Refresh my memory VZ E38 PCM vehicle alt voltage is controlled from BCM or PCM?

[Woodchukka]

VZ 6.0L had em stock ;)
Are they all they are cracked up to be or are they just a common point of failure?

[IJ.]

Refresh my memory VZ E38 PCM vehicle alt voltage is controlled from BCM or PCM?
Think it's the BCM but I'd have to check to be sure Mick..


Are they all they are cracked up to be or are they just a common point of failure?
To be honest I don't know why they changed to the clutch style..

[Micks]

Think it's the BCM but I'd have to check to be sure Mick..

Thanks, know the VE's do it through the BCM.

[steve000]

Great stuff, thanks very much for taking the time to reply!

[IJ.]

Thanks, know the VE's do it through the BCM.
Might be PCM controlled then Mick, sticks in my head it's opposite to VE.

[mcsquirt]

The overrun clutch allows the alternator to keep turning after a high speed run on the engine.

You will notice that at a low speed idle that cars without the overrun clutch the belt tensioner is "twitchy"

Here is link to a picture of the Alternator (with overrun clutch) fitted to the Pontiacs. (Notice the longer snout on the drive shaft)

http://www.americanenginesco.com/pontiac-gto-6-0l-v8-alternator-2005-2006-mitsubishi-oe-a3tg1581/

[mcsquirt]

Binnacle is now fitted - A little bit of work to fit to a VZ with Climate control but work the effort. Now getting a whole new appreciation of what is happening with the Oil Pressure (on an VZ 5.7l LS1 with 250,000km on the Clock).

I will create a separate post fro the the oil story. It will cover what can you do about "ticking lifters" (without necessarily replacing them - bugger of a job) - including Oil Viscosity (Relatively easy fix) - Oil Volume / Aeration etc - Oil Temperature (Slightly harder to fix) & Oil Pressure (Getting harder to fix) & when I get around to fitting it - Does an Oil Cooler make a difference (About middle of the road in difficulty - just a little expensive) - and would changing out the stock Oil pump for something like a Melling 10296 get us back to the near new oil pressure specs (Without having to completely rebuild the engine).

[mcsquirt]

The last of the VZ's before they went to the 6.0l engine had the Powertrain Control Module (PCM) driving the Alternator output.
This is now the standard on all later models (like the VE).

[Micks]

What oil pressure are you getting on the Ls1, eg @ idle & full noise?

[mcsquirt]

Situation now is Original LS1 - 250,000 miles on the clock "Original Oil Pump" - Running Nulon 15W 50 Full Syntheetic.
Been doing Oil Changes every 5,000km (New Oil + New Filter).


Using the Binnacle Gauge I get:

Cold Idle - 39psi (270kpa) / 4000rpm 42psi (~300kpa) - Cold idle is around 800rpm at startup then it drops to around 650rpm as the coolant temp rises and engine goes into 'closed loop' operation)
Hot Idle (in Neutral) - 29psi / 4000rpm 42psi (~300kpa) - The idle in Neutral is about 650-670rpm)
Hot idle (in Drive) - The oil pressure can avalanche away to 10-12psi (~100kpa) The idle in Drive may go as low at 510-540rpm.

In my case if the Oil pressure drops below 29psi (200kpa) for more than about 5 min I get a lifter that starts to "tick"
Using a 10W-40 like Castrol Magnatec the "tick" would come on in less than a minute during a Hot idle (particularly if idling in Drive).

[mcsquirt]

On a few ocassions (usually Very Hot 40+ day - after long running then coming to a stop on an incline / some reverse parking on hills) the engine will pop a Check Engine Oil. It may last a second or two.

This means I am getting Oil Pressures below 5 psi on some conditions.

This has me thinking its now time to fit an Oil Cooler / Replace the Oil Pump.

I have a Setrab 625 Oil Cooler plus an Improved Racing 185F Thermostat (with all the kit to fit the pipework) and I have also purchased a Melling 10296 Oil Pump.
Plan is to fit them (I will be fitting the Melling Oil Pump with the standard pressure 'blue' spring).

I have an Oil Temp & Oil Pressure gauge that will give me a better guide on what conditions produce what outcomes.

Want to get that work done ASAP and see what happens to the Oil Pressure.

[Micks]

Yes your hot pressures are on the lower side. My Brothers VY2 is suffering the same thing. I recently purchased a new Melling pump, chain kit, valve springs in preparation for the fix.

[mcsquirt]

Which Melling Pump are you going to use? M295 / 10295 / 10296?

Have you decided which spring setup you are going to use (Standard Pressure / High Pressure)?
If you are putting in a double row timing chain the Oil Pump clearances can be a problem and a Melling pump may not be the right choice.
Standard single Row Chain should be easy fit - there are some great guides on fitting the pumps on youtube.

Would be very interested to see what Oil Pressures you get after the pump is changed out.

[IJ.]

I'd just go the high pressure spring right off then adjust Hot Idle pressures with Oil viscosity if needed..

[Micks]

Which Melling Pump are you going to use? M295 / 10295 / 10296?

Have you decided which spring setup you are going to use (Standard Pressure / High Pressure)?
If you are putting in a double row timing chain the Oil Pump clearances can be a problem and a Melling pump may not be the right choice.
Standard single Row Chain should be easy fit - there are some great guides on fitting the pumps on youtube.

Would be very interested to see what Oil Pressures you get after the pump is changed out.

Really a no brainer to go the heavier (higher press) spring as they do wear out & a bit of work to strip off balancer/cover to do again. Went for a single kit with new cogs to suit.

[mcsquirt]

Finally sorted out the ticking lifters - new Melling 10296 oil pump with the standard pressure spring - also fitted a Setrab 625 oil cooler and a 185 Deg F Thermostat for the oil cooler - all the parts came from improvedracing.com in the USA. The temperature is rock solid at two needle widths above 1/4 on temp gauge. The oil pressure is never less than 200 kpa even when towing, on a 40+ degree day and when stuck in bumper to bumper holiday traffic. Woo Hoo! Been in now for about 2 years very solid and stable performance mod!