rapidoxidation

2005 E320 CDI

Took a weekender to another state a few days ago and while the car performed flawlessly over the 1K miles, he didn't do it completely happily. The dash indicators told me the convenience features were turned off (a few times but not for longer than a few minutes each), and the red "battery visit workshop" screen would come up AND the glow plug indicator would light up even though the engine was at operating temperature. All three issues at once, never independent of each other, and after the first time I saw it I set up the voltage indicator on the dash to see if anything was amiss. Nary an issue there, and the volts (running) never dropped below 13.9 (and that was with as much electrical load as I could put on the system WHILE the issue was happening). Car started and ran as normal except for the dash warnings. Plugged in the ELM327 and turned on Torque Pro and got the following codes:

P0123: Throttle/Pedal Position sensor/switch A circuit high output (this code is nearly always present and I don't believe is part of the issue at hand)
P0683: This seems to be tied to the glow plug controller communication with the ECM... but I'm not sure how to interpret it.
B2TAE: Not sure about this code, but I've seen it in the past and again don't think it is relevant but if you think otherwise, tell me why...
P2210: NOx Sensor Heater Sensor Circuit Low Input bank 1
P2211: NOx Sensor Heater Sensor Circuit High Input bank 1

I'm thinking something to do with the last two codes, in cahoots with the P0683.

Anybody got ideas where to start?

kajtek1

To start - ignore all other codes who could be result of low voltage and concentrate on real problem.
Red warning with engine running means charging problem, or system failure. So start with displaying car voltage and observing it during driving.
How old is VR ?
I had similar incident on same year car, what was triggered by not torqued battery clamp. Meaning system is very sensitive and running with wire brush and contact cleaner via charging system might be good idea.

mtrevelino

You state that the voltage never drops below 13.9, but how high does it go. It should be a steady 14.1 volts. Like Kajtek said, I would look at the voltage regulator and if you have over 130k on your cdi, replace the regulator.
Mike T.

rapidoxidation

Never saw it go over 14.1/14.2, and I had the VM on display for about 120 miles. The red screen did show a time or two during that run, but scrolling through the screens to get back to the voltage display never showed me a reading under 14 volts +- a tenth of a volt, depending on the load I put on the system (lights, seats, etc.)

The alternator/regulator was my first thought as well, but I'm thinking it would be a bit more of a solid problem if a regulator was going out. 153K miles on the car.

Kajtek, your points are valid on the charging system causing problems everywhere else and I'll double check the clamps on both the main and the aux batteries.

On another note, I ordered up an icarsoft mbII scanner today. Nothing like a good excuse to buy a new tool!

kajtek1

I think you will like MBII.
With 153 k miles your VR is due, or past due.
My general troubleshoot policy is to replace all the wearables that are due or close to due and then see if I have other problems.
When I had mentioned problems - I was on my way for weeklong vacations, so even I had scanner to monitor voltage with no hassle, I had to wait with fix till I've got home.
In that week I had "Convenience disconnect" message dozens of times, while voltage never drop below 13.9V.
At the time I was considering the system schizophrenic.