multiple trouble codes - re-starting old thread

[BradC]

My carbon pile has temperature dependent pass/fail characteristics of between 9->10V. I wouldn't condemn a battery that stayed above 10V when cranking, and in fact the last 2 batteries I replaced in the D3 both dropped to 9V toward the end of their life. They weren't replaced because they couldn't start the car, simply that they didn't have the remaining capacity to handle a few door open events while camping.

I'd be concentrating on the "pause" in the starter. Is it a noiseless pause, as in just ceases making noise briefly or are there the more telling signs of relay/solenoid clacks as it drops out and back in again?

If the pause is a common occurrence, the first thing I'd try is starting it by jumping the starter relay in the ECB. Turn the car on ready to start, but activate the starter by popping the R18 relay out of the ECB and jumpering the contacts to fire the starter motor. If you can do that reliably then the problem is upstream (ECU land) and may well be voltage related. If not and you get a clean start, do you get the TCM errors?

[twa231inCA]

Resting or float voltage may appear OK, but when starting if the volts drop to around 10v or below, there's not enough current capacity and the LR's systems report a fault. A multimeter is also not as good as a carbon pile load test, but gives you an idea at least. Before dropping in a new battery, put it on a charger for a few hours.

Battery is on maintainer (CTEK 3300) when car is not in use. I can crank multiple times without noticeable slowdown in starter performance.
At this point I can't justify $300 for new battery....
Assuming that i will flinch, which battery (US market) would you recommend? I was looking at Costco Energizer H7-AGM or similar Interstate.

[twa231inCA]

the starter's hiccup is not common (note - new starter in June, it was happening on old starter as well) . Happens once a while. I tested/replaced R18 with know good, also replaced relay for ECM and tested fuses under hood. I know there's more in BCM. Will deal with them this weekend.
basically all power and grounds verified for computers. I don't have scope for CAN at this point, on my wishlist! Working on by-pass for CAN wires to start insulating individual components at this point.


TCM - yes, getting errors when starter pause. Typical tranny info limiter performance and F. note that TCM errors are happening every 2-3 startup regardless of starter issues. they clear after shut/restart.

[Eric SDV6SE]

Assuming that i will flinch, which battery (US market) would you recommend? I was looking at Costco Energizer H7-AGM or similar Interstate.

Bosch is OEM. 300usd for a battery is not too bad at all. If you could find a suitable lithium that can handle the underbonnet temps, you'd be on a winner. I know Odyssey does a metal jacketed AGM battery, as I have one in my BMW motorcycle that seems to handle higher temperatures.

[twa231inCA]

Bosch is OEM. 300usd for a battery is not too bad at all. If you could find a suitable lithium that can handle the underbonnet temps, you'd be on a winner. I know Odyssey does a metal jacketed AGM battery, as I have one in my BMW motorcycle that seems to handle higher temperatures.

Finally i got proper tool - battery voltage when ign ON eng OFF is dropping below 12v. during crank goes below 9 (rec 8.3V)

[Eric SDV6SE]

Finally i got proper tool - battery voltage when ign ON eng OFF is dropping below 12v. during crank goes below 9 (rec 8.3V)

Battery is no good

[twa231inCA]

Battery is no good

possibly not the best - still new battery didn't change the outcome. Same type of errors.
better voltage for sure is better.

So don't jump to conclusion that battery should be replaced without more digging.

[Eric SDV6SE]

Ok, have you checked the alternator and its diode? Simple process of elimination, the battery is the usual starting point. A 'new' battery to you may have been sitting on the shelf for a bit and, if not charged just before installing, can fail faster than a 'used' battery.

You said that the cranking voltage dropped below 10V, that's a sure sign the battery , regardless of new or not, is not up to the job.

I don't think that's jumping to conclusions, but a considered opinion based on thr presented information and some past experience of this issue.

Each to their own

[Tombie]

Voltage drop like that can only really be caused by one of the following:

- Battery
- Terminal Connection
- Earth
- Starter
- Alternator Diode failure

Pulling voltage down below 10v will trip the ECU into protection

[PerthDisco]

My D will start to bong on startup and gives a suspension normal height only error as a clue the battery is getting tired which guarantees it won’t last the next winter.