Scutterpants

My 991.2 GTS developed a fault last November, dealer swapped-out the HP fuel pump and sensor. Three weeks later, after little use, it won’t start again. Now it’s been with the dealer for a month and they’re struggling to diagnose the error, which is something to do with the steering wheel module. The replaced the CAN bus but faults are persistent. Any ideas?

Here’s the list of 37 faults:

C1200B - Data bus – no message from steering wheel electronics control unit.
C1200F - Communication with steering wheel electronics (CAN comfort)
000603 - Load switch-off (eEm)
C12019 - Communication with A/C control unit
C12015 - Communication with TPM control unit
C12026 - Communication with stopwatch
C1200B - Communication with steering wheel electronics control unit (CAN chassis)
U0126 - Communication with steering wheel electronics control unit (CAN chassis)
U0212 - Communication with steering wheel electronics control unit (comfort CAN)
U0418 - Check PSM control unit fault memory content
P1023 - Fuel pressure/fuel quantity too low at start
C12085 - Check PSM control unit fault memory content
000125 - PSM activation by PTM
C1200B - Communication with steering wheel electronics control unit (CAN chassis)
000129 - PTM limp-home mode
00A150 - Warning: Parking brake
00A008 - Warning: PSM failure
C1200F - No communication with steering wheel electronics control unit
U112100 - CAN timeout error, steering-angle sensor
U112100 - No communication with steer. wh. electronics control unit (CAN drive)
C1200F - No communication with steering wheel electronics control unit (CAN bus, comfort)
C12013 - No communication with steering wheel electronics control unit
000040 - Parking brake function light (instrument cluster), electrical fault
C1200B - No communication with steering wheel electronics control unit (CAN bus, chassis)
C1200B - No communication with steering wheel electronics control unit (CAN bus, chassis)
C12085 - Check PSM control unit fault memory content
010040 - Open circuit in control unit power supply
C121A7 - Check all-wh. drive control unit fault memory content
C1219D - Check gateway control unit fault memory content
C1200B - No communication with steering wheel electronics control unit (CAN bus, chassis)
C1200B - No communication with steering wheel electronics control unit (CAN bus, chassis)
C1200F - Communication with steer. wheel electr. (CAN comfort)
C13132 - Communication with roof control unit (rear 1)
C1200B - Communication with st. wheel electronics (CAN chassis)
C1200F - Communication with steer. wheel electr. (CAN comfort)
880F0E - Left tail light faulty
C1200B - No communication with steering wheel electronics control unit (steering-angle sensor)

Jack F

Is car stock?

Andy515

I assume the battery is healthy? Could rodents have gotten to the wire harness somehow?

Scutterpants

Yes, completely stock. No mods or enhancements.

Scutterpants

Battery is fine and no rodent damage - the dealer has checked both.

desmotesta

Are you Nick Murray? @nmurray22

(apologies, my response is of no help)

Scutterpants

Ehh, nope, I’m not Nick Murray!

Does he have a fault code?

Porsche Techniker

I’d be taking a close look at the column harness, have seen these chafe before and short to ground.

Scutterpants

OPC is now waiting for delivery of a second HP fuel pump, they think a sensor on it might be causing the CAN bus errors, but not sure.

The pump is due from Germany on Friday and the OPC will fit straight away (they’re being very good about it, in fairness, and call every couple of days with an update). Let’s hope this solves the problem.

Scutterpants

Well, OPC has installed the 2nd HP fuel pump but unfortunately the errors have prevailed with low fuel pressure readings still showing, which is why the pump was replaced.

The thinking now is that the DME (‘ECU’) might be faulty, but the decision to replace this will be made after some further diagnostic trials in the next day or two.

Fingers crossed!

Scutterpants

So, this is week 15 and there’s no sign of my GTS being repaired. Still with the dealer, they’ve no idea what’s wrong. They pulled apart and reassembled various pieces of the engine, electrical system, etc etc. and the fault codes are appearing intermittently. Any advice?

RP4S911

Honestly, when I hear something that wild, maybe its the one telling the story that's not right. Possibly bad ECU in general, that's getting all the inputs and determining them, not the components.

VII7

Man that dealer is bad, or at least you got a horrible tec.
Of course it's not the sensor or pump creating a CANBUS problem because neither are on CANBUS!
These idiots are not going to repair your car they will slowly replace it with another one!
Also a CANBUS cannot be replaced, it's a comm network not a module.
You either have a bad control unit spamming the CANBUS (check with a sniffer) or a wiring problem (rodents?).
​​​​​

barncobob

im going for the rodents

2-Rotor

Do you have anything aftermarket wired into the car? Like for example rader detector/ jammer? Aftermarket stereo or dash cam? These cars dont like things spliced into the factory wiring harnesses.