C150 error - PSM failure, then dashboard like a Christmas Tree!

[remarklima]

Hi,

Over the past week or so, I've had a C150 (No communication to DME) PSM fault appear a few times. The dash says PSM failure, and it's OK after a restart.

It only appears after about 1 hour or so. Then today, I had a 3 hour drive back home and it happened after about 1 hour, but then was fine again after restarting. Then later on, I went over a seam (usual bang!) and the whole dash lit up, all things failed, spoiler, PSM, oil temp, water temp and all the dials just going up and down.

Again, it cleared after a restart, and didn't come back.

I had the rear carpets out last weekend, and it was a bit wet under there, I think from the rear wiper grommet getting loose. That's been cleaned, gummy pfleg'd and put back and no more condensation which is good - the condensation only seemed recent so hopefully it was caught quickly. But would it be plausible that the rear carpets behind the seats are still damp, and when warming up causing the humidity to break some of the circuits in the ECU / DME back there?

I'll get it all out and leave it to dry but wondered if that seems like the right cause? Or there could be something else?

 

[KarlRS]

I fear it may be the PCB on your ECU corroding, this is more a common problem on the Cabrio when the drain tubes from the clam shell area are blocked

 

[Alex]

Could be a number of different thing with a PSM failure and there's also many things (like the spoiler) that rely on that system to be able to operate correctly, like speed, etc. Hence the multiple faults.

 

[remarklima]

Thanks - mine's a coupe, I'll check the drains at the weekend and dry everything out 100%.

I assume if it's a new DME required, then any one will do from a Boxster / Cayman / 997 and can then be handed over / coded? Or does it need to be one from the same model and engine?

 

[Alex]

I very much doubt its your DME from the symptoms. Going over a bump and triggering it and also it being triggered whilst driving points to a sensor that gives a signal to the stability management. If it was triggered by moisture this wouldn't happen.

 

[KarlRS]

I am sure that someone on here will have the knowledge, but if you have a pet Indy near you I would get them to run a diagnostic check to see what the cause is. The last thing you want to do is buy something you don’t need. Could be something quite simple and cheap hopefully

 

[Alex]

Read this to give you an idea of the multiple things it could be:

Intermittent PSM Fault

Hey My 997.1 C2 2005 (UK version) seems to have an intermittent PSM warning light that comes on the dash. The fault code that I read on PSM module is "C150 - Communication DME control unit (drive)". Local Porsche Specialists told me that this fault is very vague as it basically could be...

911uk.com

 

[remarklima]

I have a Foxwell NT530 so will scan again tomorrow / Thursday.

I very much doubt its your DME from the symptoms. Going over a bump and triggering it and also it being triggered whilst driving points to a sensor that gives a signal to the stability management. If it was triggered by moisture this wouldn't happen.

However, I'd think similar it was just the PSM fault... But for the C150 DME communication error on the PSM module. And then today the whole dash going mad and all dials are just going up and down - however, the engine ran absolutely fine, just the dash went crazy and all warning lights were on.

I'll do a scan and see...

 

[Alex]

If a wheel sensor goes it can cause all sorts of havoc as that signal can be used on many different items - cruise control, spoiler deployment, speedo. You fault says DME communication error - hence it can't get a reading from a sensor. It doesn't say DME error does it.

 

[remarklima]

OK, code are... Take a breath.

DME
U0129 - Communication ride hight control unit
P0564 - cruise control input A circuit
P1614 - steering angle sensor, no communication
P1603 - airbag module, no communication
U0155 - lost communication with instrument cluster module
U0146 - communication gateway (CAN drive)
U0073 - CAN drive communication
P0503 - vehicle speed signal
P1608 - timeout cruise control message
P0074 - ambient temperature via can
P1610 - air conditioning module, no communication
P0502 - vehicle speed signal


PSM
C150 - communication DME control unit
4223 - fault in DME
C111 - fault in Drive CAN
4440 - steering angle sensor faulty
C101 - control unit faulty
C153 - communication steering wheel control unit (drive)

Instrument cluster has communication errors, gateway is OK, AC module has DME communication errors as does the front system...

Luckily, the car was running absolutely fine the whole time... Which is good and could then pull over, restart and all was well. And this only happened after a few hours driving.

 

[Alex]

Sounds like a Can bus wiring fault. Have a good read of the post I posted above and thoroughly read Demort's post on it.

 

[remarklima]

Thanks Alex, will have a read!