Engine Warning Light - P1351 & P0102

Recently I have had the engine warning light come on and a few beeps on start-up, in my 04 C3 mk1.

I have an OBDII Vehicle Fault Code Reader and the warnings that are coming up are as follows:

P1351 – IDM Input Circuit Malfunction/ Ignition Coil Control Circuit High Voltage
P0102 – MAF or VAF a circuit low input

Has anyone come across this before or knows how to resolve it? Also is it a stop driving the car until fixed or can I carry on driving for a bit until fixed?

P1351 – IDM Input Circuit Malfunction/ Ignition Coil Control Circuit High Voltage

Your generic scanner is misleading you. There are not ignition coils on a diesel engine.

P1351 is going to be the glow plug / pre heat relay not supplied

P0102 – MAF or VAF a circuit low input

It is a MAF on the diesels, so that's more generic reader codes.


You get better diagnostic codes with lexia

You can drive the ok, but does it drive ok? P0102 may mean it's lacking power?

P1351 is quite common and often not worth repairing, depending on how cold it is where you are.

Thanks for the clarification.

With the P1351 code is there any guide on how to fix/replace? I would look at trying to do it myself, but if it comes to it I may take to a garage to sort out.

I did recently have the seals on the injectors replaced. Would that be anything to do with it?

Ukphiltr7 wrote: ↑Wed Nov 24, 2021 11:52 am Thanks for the clarification.

With the P1351 code is there any guide on how to fix/replace? I would look at trying to do it myself, but if it comes to it I may take to a garage to sort out.

I did recently have the seals on the injectors replaced. Would that be anything to do with it?

Don't do the P1351 unless you are in a very old climate.

The work is to test and potentially replace the 4 glow plugs and replace the relay at the same time, after some electrical testing.

It is a very big job full of potentially snapped glow plugs that will require head removal to sort out, with no improvement in the running and only the code cleared. It is a different story in serious sub zero, then you will find the glow plugs running in post-heat mode for a short time.

But basically, check the resistance of the 4 glow plugs and if not similar to a new set, change them, and at the same time, check the relay behind the front bumper and change that.

No, the injector seals do not impact on the glow plugs.

Arfur Dent wrote: ↑Wed Nov 24, 2021 12:06 pm Don't do the P1351 unless you are in a very old climate.

But basically, check the resistance of the 4 glow plugs and if not similar to a new set, change them, and at the same time, check the relay behind the front bumper and change that.

Thanks, so to clarify you are saying:

check the resistance of the 4 glow plugs and if not similar to a new set, change them
check the relay behind the front bumper and change that

Does the front bumper have to come off to change and what is the relay called, so I can track it down?

Thanks

Ukphiltr7 wrote: ↑Wed Nov 24, 2021 12:46 pm

Arfur Dent wrote: ↑Wed Nov 24, 2021 12:06 pm Don't do the P1351 unless you are in a very old climate.

But basically, check the resistance of the 4 glow plugs and if not similar to a new set, change them, and at the same time, check the relay behind the front bumper and change that.

Thanks, so to clarify you are saying:

check the resistance of the 4 glow plugs and if not similar to a new set, change them
check the relay behind the front bumper and change that

Does the front bumper have to come off to change and what is the relay called, so I can track it down?

Thanks

Glow Plug Relay (pre/post heat relay) location

Yes, you have to at least check both parts because a bad relay will damage the glow plugs and a bad glow plug can damage the relay. so the safest thing is to do it all. But the glow plugs are very difficult to remove without breaking them and it is best to leave the P1351 alone.

One thing that I was told is that the engine management light will result in a fail in the MOT, is that correct?

Ukphiltr7 wrote: ↑Mon Dec 27, 2021 10:00 pm One thing that I was told is that the engine management light will result in a fail in the MOT, is that correct?

The examiner at the MOT station will check all warning lights in a car to see if the ESP, ABS, SRS, and TPMS lights are functioning correctly, and to make sure that they are not permanently lit up on a car.

No, MIL will not currently fail the MOT, but the others listed can/will.

Lol I see that you cannot edit posts once they are sent.

MIL - Management Information Light.
Others can - I take it you mean the ones you listed such as PAS and ABS.

Took the car to the garage today and they did not help much.

I am now thinking of replacing the MFA sensor to try and remove that one warning.
Then looking at the glow plugs.

The garage said that they think it is the Electronic Control Unit playing up. Is this easy to replace and in fact worth it?