Thread: Multiple ECU's shut down and rebooted whilst driving

So I have been running the IID tool all this week whilst driving so I can monitor voltage, current and state of charge.

I have not had a repeat issue after the 4 initial reboots on Saturday and Monday, no issues starting or driving and state of charge has stayed between 93 and 95%.

Battery voltage at the battery and at the BMS CPU has been between 13.2 and 14.2v. Battery current has been 1 to 5 amps, apart from starting the car when it spikes to negative 40+ to positive 40+ for a short period as the starter motor is going.

What I'm not sure is normal is the alternator current is between 30 and 50 amps out of the alternator whilst driving normally.

I do have a snip of the live value but not sure how to include in this post.

Thanks.

There are multiple earth points to check, that and thr connections at the battery would be first.

Then a cranking test, hook up your multimeter and note the voltage of thr battery at rest, you say 13.4V. Turn ignition on, voltage should drop a few volts as systems power up. If you wish you can turn on headlights, radion heater, ac etc to further load the systems. Start engine and note the voltage drop as the engine starts.if the voltage drops below 10v, your battery is not strong enough. Alternator will push a float charge into battery, but as its a smart alternator, it will stop charging when it senses the battery has sufficient charge based on system load. If the battery is failing, it will not hold charge and the car will shut down systems progressively. If the alternator is failing, most likely thr diode pack on the rear of it, it will put out random voltages and dpukes. The alternator is rated for 160 amps, but modulates this based on demand.

Best advice would be if the alternator and battery are original , replace both, as a dodgy alternator can fail a new battery.

Have you had the battery load tested yet??
first thing to do before just replacing bits
if a load test comes good get the alternator tested
very easy and cheap as chips when compared to replacing bits

Thanks all for tests and advise. I'm out of Melbourne until Monday then I'll find a sparky near Blackburn and get both battery and alternator tested.

If anyone has recommendations of a good local sparky in the blackburn, box hill, nunnawading area that would be useful.

Discomatt has already offered a recommendation.
"I see you are in Blackburn, maybe give AMV a call or just drop in, Greg is very helpful and knowledgeable."

Neither AMV nor Rover Range in Bentleigh have availability to diagnopse until respectively mid-April and mid-May. I had a good chat with both and neiother had experienced this issue prior.

After no issues for a week I had a repeat issue yesterday mid-day. I full charged both batteries last weekend, bench charging the 'camping' battery. I ran with only the engine battery connected for several days with zero issues, even though its over 7 years old and the second battery is less than 2 years old. I've been monitoring on the IID whilst driving and voltage has been stable, with good resiliance and not dropping under 12.4 volts unless cranking, then only for 1-2 seconds.

I am going to purchase a new battery this weekend, simply because its more than 7 years in active daily use, but I suspect it isn't the cause. The alternate also seems fine and I would prefer not to replace simply because of age and KM's as it show no symptoms of failing.

I'm at a bit of a dead end tbh. I am going to hard reset at the same time I replace primary battery, and I am also going to take the Traxide out of the loop for a couple of weeks to go back to standard config.

IID diagnostics still show muiltiple and simultaneous CPU faults when the systems restart, so no change there. Has now happened 5 or 6 times. Interestingly I have had am intermittent issue with the fob not being able to unlock the car over the last few weeks and I suspect it may be related to this issue as if I try for a couple of minutes it will suddenly unlock and then be fine for a few days. occurs with both fobs and I have changed their batteries with fresh ones several times.

As stated I am at a dead end, at least it still drives during the system reboots, however not being able to signal lane changes during the events, or use reversing camera and sensors after until a car restart is also a little dangerous.

So I took for a load test, fully expecting to need to replace the primary battery, even took it to a battery joint that had a vested interest in failing the battery so they could sell a new one to me. And it passed, not even on the line, but with plenty of spare capacity.

I had not charghed the batteries since last weekend, Ive driven only short 15-30 minute trips, I had not used the car for 2 days and it was only a 15 minute drive to the battery joint, so every chance for a weak battery to fail the test. But it did not.

On top of that the IID shows the battery recharging quickly after a start then settling down to 15-20% alternator load depending on what I am running in the disco - audio system, air system etc.

I'll find somewhere to test the alternator this week, and give the owner of Rova Range a call when he is back but at this point I am baffled.