760Li Gremlins :(

[MrBurger]

Hi
As some may know if you're members of *another forum lol* I'm trying to hunt down an issue on my 2007 760Li.

Symptoms:
iDrive Screen flickers (regardless of source) when revving the engine.
Transmission Indicator lights flicker when revving the engine.
(The above can sometimes happen when idling)

When driving (which is no longer the case in order to preserve my transmission) the car slips during acceleration or slips into P from D when moving off from a stationary position. It will also slam (like it's in 2 gears) every time you accelerate hard.

Sometimes, it will just revert from D or R into P if it's feeling especially troublesome

I recently had a CHF fluid leak which caused the power steering/active suspension to fail (which is near the alternator of course).

Video Evidence:
http://www.datart.co.uk/BMW_E66_FAULT.html (The INPA error was for my benefit and has not been seen since)
http://www.datart.co.uk/BMW_E66_ELEC_FAULT.html
http://www.datart.co.uk/BMW_E66_ELEC_FAULT_2.html

Work done:
Power steering hoses replaced to repair fluid leak.
Transmission ATF replaced with LG6
Transmission Sleeve replaced
Transmission Seals (x4) replaced
Transmission Bridge Adapter replaced
Power Module (in trunk) replaced
SGM (combined SIM/ZGM behind glovebox) replaced

As the issue seems to relate to the electronics and more specifically to the quality of the voltage from the alternator, which charges my relatively new AGM 019 90Ah battery at 14.5v (or thereabouts), can anyone offer any more pointers

Is it possible to disconnect the positive feed from the alternator, running the car from the battery alone, to see if it still has these issues..?

There are no error codes and the car shifts into D, R, P and N fine (and between M1 through M3) while stationary 99% of the time, until I get an electrical gremlin which causes an issue..

I will find the solution to this but if anyone has any ideas, I would welcome your input.

Regards
Mr_B

[jclausen]

Don't run the engine with out the alternator hooked up. You could have the voltage output of the alternator checked, but also check the ac leakage from the alternator if it is out of spec it will cause all sorts of issues or maybe you have water damage from the rains. We had a 745 that was doing all sorts of things, tons of warning lights on, then we found water under the back seat and sitting in the water was this inch by inch square connector with a few ribbon cables connected and a resistor it. Replaced it, fixed. The customer did finally mention that the rear carpets had been getting very wet when it rained, we also cleaned out the sunroof drains

[MrBurger]

Why is it not safe to run the car without the alternator for 5 minutes?

It's a sure fire way of ruling out the alternator, isn't it?

I only want to fire it up and rev the engine to see if the electronics freak out. Apart from the car reporting an alternator fault, what else could go wrong?

As for rain, I don't think we've had much recently so I doubt this is rain related sadly.

Regards
Mr_B

[XAlt]

Why is it not safe to run the car without the alternator for 5 minutes?

It's a sure fire way of ruling out the alternator, isn't it?

I only want to fire it up and rev the engine to see if the electronics freak out. Apart from the car reporting an alternator fault, what else could go wrong?

As for rain, I don't think we've had much recently so I doubt this is rain related sadly.

Regards
Mr_B

Rain can sit for a very long time.

Run it with the alt out, but the electronics will probably take a piss for that very reason.

[MrBurger]

Run it with the alt out, but the electronics will probably take a piss for that very reason.

Hi
Could you expand on why..?

The car is a DC device and you can't get more DC than a battery. I appreciate the load on the battery would increase, but I'm only talking about a few minutes while ruling out the alternator (or not). I wasn't planning on actually driving it anywhere.

Regards
Mr_B

[MrBurger]

Hi
Here's a quick update..

Once I finally sorted out my ISTA PC, it displayed the DSC module in red, suggesting I need to check the 15WUP signal...

Anyways, after a few days of that (and not being able to engage Auto-P) I tried the steering wheel button I have programmed to start/stop Auto-Park and Auto-P started perfectly..(I couldn't start/stop Auto-P via the iDrive menu option, maybe due to the DSC being dead when the iDrive booted??)

I then re-scanned the car again and the DSC showed as green..

I then called the ECU functions of the DSC and the ECU failed to respond, again showing as red..

I pressed the steering wheel button again to start Auto-P and again it started fine..

Following that, ISTA connected to the DSC each time I tried..(even after 6 hours of letting it rest)

The Power Module fault continues to report A148 (open circuit)

I did try another Power Module, but the same error is reported so ISTA's suggestion on replacement doesn't resolve anything sadly.

I think this one is beyond computer diagnostics..

I will find the ABS/DSC and see if anything is obvious though..

I suppose I need to find something common to both the IDrive and the mechatronics as it's those that are clearly indicating a fault condition..

Regards
Mr_B