Glow Plug Circuit Fault: P0672 & P0673 Codes

Hello everyone,

I'm facing a problem where I can't pinpoint the exact cause of the error.
The following text is about the vehicle:
Golf 5
2.0 TDI BKD
Manufactured in 2004.
205,000 km

Background:
I disconnected the battery in order to replace the steering wheel. Before the steering wheel was installed, I realized that something was still missing, so I stopped the process and reconnected the battery.

Then I went to get gas (filling the tank completely with 50 liters took an unusually long time, about 10 minutes) --> This information is important for my conspiracy theory .


Symptoms:
- The car doesn't start easily/starts very poorly when warm (and this isn't referring to the well-known warm start issue).

- If I force the car to start, I have to make the starter motor work for 6-15 seconds.

- The engine stalls while driving, especially when the RPM drops. Sometimes it idles up to 800-900 RPM, but sometimes it just stalls (e.g., at a traffic light or intersection --> which is very annoying because it then gurgles for a long time before restarting).

- If the car stands for several hours and cools down completely, it starts immediately without any problems. However, once the engine reaches its operating temperature of 90°C, the car starts to stall again at unpredictable intervals.

- Incorrect fuel combustion, the car smells like soot.

- At 2000 RPM, there are noticeable jolts or jerks when the accelerator pedal is held steady.


VCDS log.
I can't shake the feeling that I can't rely on the logbook... because when the engine is warm, I don't need glow plugs to start it.
I think there's something wrong with one of the sensors (temperature, fuel injection system).

Code:

Adresse 01: Motorelektronik        Labeldatei: RKS\03G-906-016-BKD.lbl    Teilenummer SW: 03G 906 016 KC    HW: 028 101 190 3    Bauteil: R4 2,0L EDC G000SG  9971     Revision: 12345678    Seriennummer: VWZ7Z0D0829192    Codierung: 0000072    Betriebsnr.: WSC 44458 136 85911    VCID: 6ED589C6799CF06E79B-803B 2 Fehlercodes gefunden: 17056 - Glühkerze Zylinder 2 (Q11)             P0672 - 000 - elektrischer Fehler im Stromkreis              Freeze Frame:                     Drehzahl: 798 /min                     Drehmoment: 70.0 Nm                     Geschwindigkeit: 0.0 km/h                     Last: 0.0 %                     Spannung: 14.14 V                     Binärwert: 00101100                     Temperatur: 16.2∞C                     Binärwert: 10110000 17057 - Glühkerze Zylinder 3 (Q12)             P0673 - 000 - elektrischer Fehler im Stromkreis              Freeze Frame:                     Drehzahl: 798 /min                     Drehmoment: 70.0 Nm                     Geschwindigkeit: 0.0 km/h                     Last: 0.0 %                     Spannung: 14.14 V                     Binärwert: 00101100                     Temperatur: 16.2∞C                     Binärwert: 10110000 Readiness: 0 0 0 0 0

My thoughts on the cause:

Temperature sensor defective.
- The fuel pump is not providing enough fuel.
- The engine is reporting as cold, even though it is warm.

Idle speed is incorrect.
- Sensor malfunction?
- Adjustment/locking options?

Fear: Preheating system?


I found the error code again, but the topic isn't very extensive.
/viewtopic.php?t=26204&highlight=17056


Here are a few instructions and tips regarding glow plug issues:
http://forums.tdiclub.com/showthread.php?t=79819

Hi,
It is unclear whether the excerpt from the scan refers to a warm or cold engine.
Defective temperature sensors can be identified by comparing all temperature readings together and with the environmental conditions. To do this, either view the corresponding measurement blocks or a suitable compilation of individual measurements and post them here.
The problem is probably less related to the glow plugs, even if some are defective, because it's not just a starting problem.
I would also consider the throttle valve in this situation.
Sure, here's a car scan:
[Car Scan]
Make: Toyota
Model: Camry
Year: 2018
Mileage: 75,000 miles
Engine: 2.5L 4-cylinder
Transmission: Automatic
Fuel: Gasoline
Color: Silver
VIN: 1234567890ABCDEFG

This scan shows the basic information about a Toyota Camry. It includes the make, model, year, mileage, engine, transmission, fuel, color, and VIN.
hg
Herbert.

Hello,

Quote:

2 error codes found: 17056 - Glow plug, cylinder 2 (Q11) P0672 - 000 - Electrical fault in circuit. Freeze Frame: Speed: 798 RPM Torque: 70.0 Nm Speed: 0.0 km/h Last: 0.0% Voltage: 14.14 V Binary value: 00101100 Temperature: 16.2°C Binary value: 10110000 17057 - Spark plug, cylinder 3 (Q12) P0673 - 000 - Electrical fault in the circuit. Freeze Frame: Speed: 798 RPM Torque: 70.0 Nm Speed: 0.0 km/h Last: 0.0% Voltage: 14.14 V Binary value: 00101100 Temperature: 16.2°C Binary value: 10110000

That is not a log, but the content of the error memory of the engine control unit.

The glow plugs can and will be activated in operating conditions other than during cold starts to achieve better exhaust emissions in relatively modern engines.
That is to say, it doesn't really tell us much at first.

Your starting problems could very well be related to an incorrect temperature reading.
In measurement block 7 of the engine control unit (or the corresponding value in the extended measurement blocks), you will find the coolant temperature. This value is relevant for the starting process, so check it and see if it seems reasonable.
The coolant temperature indicator on the instrument cluster is relatively independent of the temperature sensor, which has two sensors: one for the engine and one for the display.

Unfortunately, the coolant temperature sensor can sometimes provide normal readings for a short period and then suddenly give completely incorrect values. Therefore, if you suspect a problem, it's best to replace it. It costs less than 10 EUR from most auto parts stores.

Unfortunately, other factors can also be the cause, such as air or exhaust gases in the fuel system or in the corresponding areas for fuel supply in the cylinder head, Hall sensors, etc.

See also:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

and

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Thank you in advance for the information.

- The intake manifold flap has only been installed for 2,000 kilometers (it was only replaced due to a defect).

- I once analyzed the temperature sensors using extended data blocks. Indeed, I'm getting some strange readings (see the images in the attachment). These occur sporadically, meaning that sometimes the normal value is displayed, and sometimes I get signals with 0°C or "not available."
--> The values change in real-time, updating every second.


I have attached the VCDS Autoscan showing the error related to the glow plugs. I had cleared those errors after the last scan, but this time they didn't reappear; instead, other errors appeared. I have also attached the new Autoscan.

I'm also measuring the resistance on the glow plugs to get a clearer picture of their condition.

Quote:

Address 03: Brake Electronics Label file: RKS\1K0-907-379-MK60-F.lbl Part number: 1K0 907 379 K Component: ESP FRONT MK60 0104 Encoding: 0023170 Operating number: WSC 00028 028 00104 VCID: 3A7D759675546CCE953-806F "One error found:" 00668 - Voltage at terminal 30. 002 - Lower limit exceeded - Intermittent.

Along with the strange temperature readings (erratic values would indicate a faulty sensor or cable, but the °C values are not being converted into volts or a bitmask) in the diagnostics, is the power supply okay?

Please check the battery, fuses, fuse box, terminals, etc.
If the car doesn't start, please pay close attention to the warning lights on the dashboard to see if any are lit up or not lit up compared to a normal start.

Search the forum for "Relais 109" (it might have a different number for you).

Best regards, Rainer.

I've also read about the issue with relay 109.
I will first check the fuses and other components, and then, as a precaution, I will replace the temperature sensor and relay 109.

If the problem persists, I will start working on the glow plugs/wiring harness - I think that's the most logical approach.

I'll get back to you with new information - thanks so far!

Status update:

The following items have now been replaced:
- Glow plugs (two were actually defective).
--> I measured the resistance with a multimeter, and after removing them, I checked again by applying 12V to the glow plugs. Two of them were completely unresponsive.

- Temperature sensor (replaced as a precaution).
--> There's a leak with the coolant, for those who want to replicate: place a drip tray underneath .

- Replaced the relay for the MSG (as a precaution).
--> In the Golf 5 GT (manufactured in 2005), there is no more relay 109. I replaced relay 460 (terminal 75) here.

Cleaned:
- LMM, following the instructions below: https://community.dieselschrauber.org/en/viewtopic.php?t=3347
"Indeed, the hole behind the sensor has had some effect, but not yet 100%. I have analyzed the readings at idle and full load. The idle readings are within range (between 150-300mg), but the values drop significantly under full load (full load = 500-550mg)."

I placed an order based on a hunch.
- Crankshaft sensor (being replaced as a precaution).
--> These symptoms are consistent with the car stalling (engine speed at idle) and the difficulty starting.

- After the crankshaft sensor, a new mass airflow sensor (MAF) may be necessary (if the values are truly not within the acceptable range --> for this, I would need the experience of someone with years of expertise).


Conclusion based on the points currently being implemented:
- Jerking/Hesitation at a constant pedal position = fixed.
- Warmstart = reduces time (felt, not measured).

If the crankshaft sensor has been replaced, I will let you know.

EDIT:
Unfortunately, this error still persists. Do you have any suggestions on how I could test it?

Code:

Adresse 03: Bremsenelektronik Labeldatei: RKS\1K0-907-379-MK60-F.lbl Teilenummer: 1K0 907 379 K Bauteil: ESP FRONT MK60 0104 Codierung: 0023170 Betriebsnr.: WSC 00028 028 00104 VCID: 3A7D759675546CCE953-806F 1 Fehler gefunden: 00668 - Bordspannung Klemme 30 002 - unterer Grenzwert unterschritten - Sporadisch

Quote:

- LMM, following the instructions below: https://community.dieselschrauber.org/en/viewtopic.php?t=3347 "Indeed, the hole behind the sensor has had some effect, but not yet 100%. I have analyzed the readings at idle and full load. The idle readings are within range (between 150-300mg), but the values drop significantly under full load (full load = 500-550mg)."

I would continue using that brand, specifically either the original brand or Bosch.
Prerequisites: The camshaft must be functioning correctly, the intake and exhaust passages must be clear, and boost pressure must be building.

This has nothing to do with the delayed starting. I would check the battery and, as mentioned before, the cable connections.

Okay, that's why I've become aware of the crankshaft sensor. The camshaft doesn't affect it, otherwise I would have completely different problems .

Battery delivers:
Motor ON = 13.97 V
Engine OFF = 12.7 V
--> Therefore, the battery is not the source of the problem.

The starter motor is also working properly because:
- The starter motor was only replaced 1.5 years ago (I hope nobody gets mad at me for saying that).
- Engine cold --> Does it start immediately?
- The starter motor isn't weakening; it's been running for a long time before the car starts.

Since the starting times vary with a warm engine (sometimes longer, sometimes shorter), it theoretically shouldn't be the starter motor, otherwise the starting time would always increase (I don't know of any starter that fixes itself ).

As soon as the parts are in, I'll provide more information. In the meantime, feel free to share any ideas you have – I welcome any input.

Quote:

Battery delivers: Motor ON = 13.97 V Engine OFF = 12.7 V --> Therefore, the battery is not the source of the error.

And under load, when starting?

12.7V can sometimes even revive a defective battery.

I apologize for the fact that no new information has been added here for some time.

Back to the topic.
I've also measured the battery recently, and the results are as follows:
Ignition off: 12.7V.
Ignition ON: 12.3V
Startup process: 10.xV (I mean I've seen versions like 10.0, 10.1).
Motor ON: 13.7V


Is the voltage during the startup process okay?
Just for your information: There's also an amplifier connected to the same battery, which only powers a subwoofer.

Over the past two weeks, I've noticed that when I don't use the car for a whole day, it takes a little longer to start.

A few weeks ago, we had a Touran, also with a BKD engine, that was very difficult to start when warm and had a lot of hesitation.

The cause was faulty power distribution units (PDUs). The power distribution cable harness was also replaced.

Unfortunately, this doesn't correlate with the steering wheel replacement that was performed previously.

The voltage drop doesn't seem critical at first... although I'm seeing about 10.5 volts at the starter when starting with a healthy battery. However, the starter motor speed is the crucial factor.

Schon mal geprüft ob der abgestellte warme Motor während der Fahrt mit eingelegtem Gang und der Kupplung (ganz kurzer Moment einkuppeln) anspringt...... geht am besten bei 50 km/h und 3. Gabbreviations

But be careful... don't remove the ignition key from the lock while driving...

If it's due to the starter motor, or a too-low starting speed, then...
It should start up on the first rotation of the crankshaft.

That sounds fine - so I don't have to replace the battery .

I hope it's not a problem with the power steering elements. It's "supposedly" unlikely, since they were "only" replaced about 90,000 to 100,000 km ago... or it could be (oh dear... the kilometers just fly by, I'm surprised myself).

ich prüfe das mal mit dem Anspringen bei 50km/h und 3. Gang.
--> The best approach here is to turn off the engine while driving, put it in 3rd gear, and briefly engage the clutch, correct?

Tomorrow, the heat exchanger needs to be checked, which I think will be a problem.

Quote:

--> The best approach here is to turn off the engine during the descent, put it in 3rd gear, and briefly engage the clutch, correct?

Correct ... very briefly.

P.S.: Has the KR filter already been in the vehicle for 100,000 km? If so, it might be a good idea to replace it to rule it out as a potential source of the problem. Clogged filters can also cause the engine to jerk or stumble.

The fuel filter has been replaced every 90,000 km .
I'll report again in a few days.

By the way, I haven't managed to replace the crankshaft sensor yet, as it's located directly behind the oil cooler .
I might need to jack up the car a bit higher, as my equipment at home isn't quite sufficient anymore.

Hi!

There was that thing about the starting speed, wasn't there?
The engine starts normally, but when it's warm and the engine speed is below a certain level, the starting process is blocked. It only starts after several seconds.
And at -15°C, the engine starts immediately.
I had that problem once; it was the battery.

Sometimes, when it takes a long time to start (especially when the engine is warm), it's helpful to check the engine speed using a laptop.
I don't remember the value anymore.