Diesel injector woes

[21TonyK]

Having posted on the other thread a price of 650 to replace an injector on 21Jnrs GTD the damn started playing up again this morning. A quick scan is showing the same code on a different injector, Jnr is most definately not happy and its going back to the garage tomorrow.

Whats the chances its not the injector itself but something else causing the code? He's not relishijng the idea of another 650 for another injector!

And, that aside, am I right in thinking its not that big a job to replace them? 650 so swap a part seems a bit OTT but then I really dont know whats involved?

I have a 5 day weekend coming up and happy to get the spanners out.

[normalbloke]

Possible early demise of the HPFP?

[21TonyK]

I think this is the problem. Having just spent 650 having one injector done it sounds like another has gone (although that sounds very suspect) or, as you say could just be a symptom of a failure elsewhere or he needs all 4 injectors replaced.

Either way its a crap thing for car with 50K on it if he faces a 2K bill to fix it

[normalbloke]

Have you spoken to Dark side for an opinion?

[stevemcs]

Have you had all the injectors pulled out and had then all tested or just replaced one based on a fault code ?

[21TonyK]

so far just one based on a code, its back in to the same garage today

[E-bmw]

It could be that they have managed to disturb the plug on the second one.

[Richard-D]

What was the code? Most injector codes relate to the control side, so can't be related to a HPFP breaking down. With a bit more information (engine type and code stored) I (or someone else) might be able to point you in the right direction (or avoid accusing a garage of something silly and souring the relationship).

[21TonyK]

I’ll post up the code etc when I get home. Any steer on it would be appreciated.

[Richard-D]

Just had a look at your other thread which had the fault code on (P1264).

P1264 is a short between the high side and the low side of the injector circuit on cylinder 4. If the code you now have is P1264 then there is either a fault in the loom, the ECU or you have a faulty injector.

If you have fault code P1261-63 then the ECU believes there is a short between the high and low side of the injector on the corresponding cylinder. There is also the potential for a fault in the loom or ECU as above.

What I would do in either case is the same. I would clear the code and ensure it reappears straight away to confirm the short is present. I would then swap the plugs on the injector with a fault and the one next to it then clear the code again. Then turn the ignition on (don't start it). The ECU will then perform a test of the engine circuits. If the fault stays on the same cylinder the wiring or ECU is faulty (almost always wiring). If the fault moves to the adjacent cylinder the injector is faulty.

This fault (codes above) has no relation to the HPFP.

Edited by Richard-D on Thursday 23 January 17:31

[21TonyK]

This the the OBD report... if anyone can shed any light it would be appreciated.

Car Scanner ELM OBD2
Version: 1.114.9/1.114.9/iOS
DTC report
Connection profile: Volkswagen MQB, PQ26: Diesel DPF var.3Date: 1/16/2025 6:43:47 PM
VIN: WVWZZZAUZJW281493

======================

OBD-II
No DTC found.

======================

19. CAN Gateway
No DTC found.

======================

09. Onboard supply control unit
No DTC found.

======================

03. ABS control unit
No DTC found.

======================

01. Engine control unit01. Engine control unit
DTCs: 1

---

21089 [0x005261] Archive (inactive)
P020200: Cylinder 2- Injector Circuit
Status bits: 1
Priority: 2
Frequency: 1
Unlearning index: 255
Odometer: 92348 km
Date, time: 2025.01.15 23:50:13
Engine RPM: 1305 rpm
Calculated engine load value: 52.55 %
Vehicle speed: 49 km/h
Engine coolant temperature: 48 ℃
Engine oil temperature: 44 ℃
Barometric pressure: 103 kPa
Klemme 30 voltage: 14
Paramteric values: 20 96 27 10 6C 03 11 A6 01 C9 11 39 04 F6 10 FB 14 2B 16 25 0A D3 12 FB 0B CF
Status: Test failed since last DTC clear, Test not completed during this operation cycle

======================

04. Power steering
No DTC found.

======================

08. Heater and climate08. Heater and climate
DTCs: 2

---

1048834 [0x100102] Archive (inactive)
B10CD00: Function limitation due to energy management
PTC-Reduzierung durch BCM
Status bits: 1
Priority: 7
Frequency: 1
Unlearning index: 207
Odometer: 92017 km
Date, time: 2025.01.10 10:26:22
Paramteric values: 02 86 8D 27 C1 D3
Status: Confirmed

---

1048835 [0x100103] Archive (inactive)
P171900: Function restriction by engine control module
PTC-Reduzierung durch MSG
Status bits: 1
Priority: 6
Frequency: 2
Unlearning index: 208
Odometer: 92017 km
Date, time: 2025.01.10 10:27:42
Paramteric values: 02 86 8D 27 C1 F3
Status: Confirmed

======================

10. Parking Assistant 2
No DTC found.

======================

13. Active cruise control13. Active cruise control
DTCs: 1

---

00836 [0x000344] Archive (inactive)
U112300: Databus error value received
FAULT_PREDICTIVE_ROUTEDATA_SIGNALERROR_RECEIVED
U112200: Databus implausible message
FAULT_CIM_ALV_BV1_Obj_03_C
Status bits: 1
Priority: 6
Frequency: 254
Unlearning index: 215
Odometer: 92070 km
Date, time: 2025.01.12 14:01:22
Paramteric values: 02 8D 3F 02 85 7D 10 11 00 00 10 12 00 00 10 2E 00
Status: Confirmed

======================

15. SRS
No DTC found.

======================

16. Steering column
No DTC found.

======================

17. Dashboard
No DTC found.

======================

42. Driver door electronic equipment
No DTC found.

======================

44. Power steering
No DTC found.

======================

52. Front passenger door electronics
No DTC found.

======================

5F. Electronic Information System 1
No DTC found.

======================

76. Parking assistant
No DTC found.

======================

A9. Structure-Borne Sound Actuator / Exhaust flaps (UDS)
No DTC found.

======================

4B. Multi-functional unit (29 bit)
No DTC found.

[Richard-D]

A P0202 is a slightly different fault to your previous one. It's also not a current fault, but a history code.

That code shows a break in the circuit through the injector. The fault could be in the wiring or the injector itself. There is a possibility that the connector was disturbed during the previous fault and not fully reconnected. Typically you wouldn't need to disconnect other injectors to replace one but I don't know this engine. I think it's very unlikely the garage has done anything to cause this.

The awkward thing is that it is an intermittent fault (must be as it's not a current code but is a history code). I would expect the engine light to turn itself off with the fault code shown. Is the engine light still on?

[21TonyK]

Richard-D said:

A P0202 is a slightly different fault to your previous one. It's also not a current fault, but a history code.

That code shows a break in the circuit through the injector. The fault could be in the wiring or the injector itself. There is a possibility that the connector was disturbed during the previous fault and not fully reconnected. Typically you wouldn't need to disconnect other injectors to replace one but I don't know this engine. I think it's very unlikely the garage has done anything to cause this.

The awkward thing is that it is an intermittent fault (must be as it's not a current code but is a history code). I would expect the engine light to turn itself off with the fault code shown. Is the engine light still on?

Thanks for looking, I think you might be looking at someone else's post though. I mentioned the cost elsewhere but not the codes.

I'll check with 21Jnr when hes back later as to the sequence of events, his car is still at the garage and he's borrowing mine now for a bit.

The garage have said they want more time to look to try to find the issue rather than just replacing injectors so thats a positive (I think)

[Richard-D]

You're right. I'd seen you had commented on a recent thread on injectors and assumed it was your car being talked about.

What I had posted still applies and the method I described above will answer the query of whether it's an injector or wiring/ECU fault. The issue you will have is chasing an intermittent fault though. Can't fix something that isn't broken.

[21TonyK]

Thanks for the time and advice.

Just spoken with Jnr and this code came up on cylinder 2, the injector replaced and the code cleared. a day later the same code on cylinder 3.

Smacks of something causing it?

[stevemcs]

As Richard said, scan it, clear codes, scan it and turn the engine on but don’t start it, if the code comes back then it’s most likely wiring, check the connects - we had one in a few weeks ago where mice had been dining.

[21TonyK]

Thanks again, I have passed this on and will report back. Might find the garage solve it tomorrow and its a simple thing. If not the cars will be back tomorrow and we'll go from there.