Help diagnosing “Service ESP” [Solved!]

[Skylarking]

Just keep in mind that the VF smart charging system uses the battery state of charge to optimise the charge rate.

Battery state of charge is calculated by the BCM using a current sensor at the battery terminal itself. The BCM can sense the current going in and out of the battery itself and uses some voodoo magic to decide how much energy the alternator should push into the battery… If the current sensor or the wiring to BCM is faulty you will have battery charge issues even if the battery and alternator are ok.

Have no idea if the battery current sensor line on your graph is ok…

 

[kveldulv]

If the current sensor or the wiring to BCM is faulty you will have battery charge issues even if the battery and alternator are ok.

In which case the battery should degrade over time. I was thinking along similar lines, so went and bought a battery monitor. Haven't installed it yet, but will be interesting to independently observe it.

 

[kveldulv]

I’m sure everyone will get sick of this thread, but I plan to keep posting until it’s fixed, as I personally find nothing worse than searching for an issue that is exactly the problem you’re having, and the thread just stops...

So, around town (drive to and from work), the issue pretty much only happens under brakes.

• Never seems to happen in the first few minutes (if it was a wire/short it would always do it, no?)
• Doesn’t happen under gentle braking
• On a longer stop, the error will come/go in unison with pressing/releasing the brake
• Never happens once stopped (e.g. pumping brake pedal does nothing when at rest. Dash is normal)

Once it has happened, there can sometimes be some “aftershocks” in that it will happen even when not braking, but generally settles back to normal.

However, last weekend I went out on the highway. At 110km/h the Service ESP / Dials dropping out was almost constant (obviously no braking involved). Real annoying in speed-camera central.

Anyway, I’ve been keeping an eye on the battery/charging. I’m still not sure if it’s functioning normally as I haven’t had the chance to get things properly tested - with the time of year, and all.

Here’s a typical (drive to/from work) day as logged by the battery monitor:

Here’s the highway run:

Driving to work after the battery was charged overnight:

Any thoughts? Areas to examine/log in GDS2?
One thing I did check was wheel speeds, and all four wheel sensors are in agreement with sensible values.

 

[Forg]

Hey, you know in farming when you get male animals in to get your female animals pregnant, and that's sometimes called servicing?

Maybe "Service ESP" is your car swearing at the ESP?
Or maybe you're supposed to **** it?

 

[Skylarking]

I still suspect your battery or alternator is intermittently cactus…

As my car isn’t driven often, but after starting the car which is a strong and positive start, I often see 15V on the DIC. Interestingly it quickly drops to 14V over a few minutes and then slowly drops further to mid(ish) 13V.

You seeing 13.0V seems a little on the low side to me, hence why I think battery but more likely charge circuit…

It was easier to diagnose on the older dumber charging circuits in cars gone by… But still, sometimes faults eluded dealer service technicians. In on case, I had a flickering charge lamp on braking and sometimes on idle… The dealer looked at it until blue in the face and I finally cracked it with these dumb knuckles that wouldn’t change the alternator to test if that was the issue… So I gave them the middle finger and went home as there was no real ACL back then… At home I chucked a scope on across the battery terminals and zoomed into the ripple waveform… At odd times I could see spikes that seems to imply one diode was failing… Well I pulled out the alternator and looked at the circuit board holding the disorders and noticed one diode lead didn’t have the hole in the circuit board filled with solder and the bit that was there was cracked… Grabber the solder ping iron and did what the factory hadn’t done and correctly soldered the diode in place… That resolved the issue… An issue that became apparent because of an engine idle and running roughness tnat was traced to an assembly problem which the dealer did fix… But this made the fault less frequent and more intermittent in nature…

So, I’d download the VF workshop manual from here (if you don’t have a copy already) and read the part about charging and battery management (if you haven’t yet done so). Look at the description & any wiring diagram and see how the BMC actually controls the charge voltage. If it’s possible, bypass that smart control so you can manually control and thus test the alternator output while looking at the alternator voltage waveform (ripple voltage). But before this, best to load test the battery as that should be your first step...

As good as GDS2 may be, it may simply be leading you into la la land with overly complicated tracing options that the tool provides. As is, we simply don’t know the exact details of the battery management logic that is coded within the BCM so I like the KISS principle and basic alternator operation isn’t rocket science. In tha5 contact going back to basics and ensuring the alternator behaves correctly when it’s told to do sometime is the second step… If all proves ok, then it may be BMC or BMC software issues …

Goog luck with it and do let us know how you progress.

 

[Geoff6666]

I didn't have the messages that you have, and it wasn't random, but I had an alternator that failed. It was caused by the clutch on the pulley failing. This caused the alternator to not spin. If it was happening at random, then it may cause those issues. Just something else you can check. Good luck.

 

[kveldulv]

Hey, you know in farming when you get male animals in to get your female animals pregnant, and that's sometimes called servicing?

Maybe "Service ESP" is your car swearing at the ESP?
Or maybe you're supposed to **** it?

Humor often goes over my head... so sorry if I've mis-understood, but if the insinuation is that I should get it serviced, then as per my opening sentence in this thread, that's exactly what I tried to do! From the dealer I bought the car new. Who've always serviced it. Unfortunately after 3 days, they said "sorry, no idea."

So, I was hoping to use a bit of collective brain-power and my time (instead of supplying a never-ending stream of cash to the dealer) to hopefully at least narrow-in on the problem!

I genuinely appreciate all contributions though, so thank you.

 

[kveldulv]

I still suspect your battery or alternator is intermittently cactus…
[...]
I had a flickering charge lamp on braking and sometimes on idle… The dealer looked at it until blue in the face and I finally cracked it with these dumb knuckles that wouldn’t change the alternator to test if that was the issue…
[...]
So, I’d download the VF workshop manual
[...]
Goog luck with it and do let us know how you progress.

Yeah, I've still can't shake the feeling that something ain't right with the battery and/or charging.
Unfortunately, I've not been able to get it tested this-side of Xmas.

My wife's VF does not behave like mine. In the research I've done, I came across reference that it's normal, but I just never recall mine pretty much sitting in low 12s all the time.

I do have the Workshop manual, so will be doing a bit of reading over Xmas.

Your alternator sounds like the kind of nightmare I'll probably turn out to have.
I've got someone that can help me scope the battery voltage - but that'll have to be in the new year once I'm back at work.

Thanks for all the suggestions!

 

[kveldulv]

I had an alternator that failed. It was caused by the clutch on the pulley failing. This caused the alternator to not spin. If it was happening at random, then it may cause those issues. Just something else you can check. Good luck.

After reading yours and Skylarking's comment above, I think the alternator will come under scrutiny next.

 

[kveldulv]

Since my last post, I have spent so much time and energy investigating this... and now I can finally provide an update and a conclusion to this saga!

At one point, I decided to pay for 3 days of access to Service Info on acdelcotds.com to ensure I had the most accurate wiring diagrams available.

Making the most of it, I put in my VIN and started browsing through Service Bulletins when I came across #18-NA-270 (Document ID: 5138979). This perfectly matched my problems, from the error codes and modules they’re observed in, through to only happening when hot and under brakes.

At this point (first time I’d used the site) I noticed I had my region set to North America - so my VIN coming up as a “Camaro” wasn’t “a quirk” as I initially thought.

After changing the region to Australia/NZ, my VIN correctly identified as a Commodore. There was a similar Service Bulletin (#17-H-030; Document ID: 4855165) listed, with the photos in it now matching what I’d expect.

The bulletin describes a “rub condition” on the front of the engine which has obviously been known to wear through the wiring harness there.

Using mirrors, and a crappy old borescope camera, I tried my best to inspect for any damage, but could not see any. So, I just pulled the wires as far away from the engine as I could. (One of the steps in the bulletin.)

I went out for a drive, and I couldn’t believe it. For the first time in as long as I can remember, no dials dropping out, no glitching, no “Service ESP”, no other random messages, no issues whatsoever! The “Check Engine Light” also switched itself off.

To be sure, I wanted to give it some time.

It has been over a month now, and the issues have not happened since. So whilst I still need to find and fix where it has rubbed through, at least I know exactly where the problem lies!

It really surprised me, because it’s obviously happened enough to make a service bulletin about it, but nothing of the sort turned up in any searches I did (nor did it occur to the dealer who had my car for three days)

So, hopefully this here will add another possibility for anyone experiencing this dreaded issue.