Exhaust pressure sensor 1 (G450): Short circuit to positive terminal

Last week, I replaced the mass airflow sensor (MAF) as a precaution due to various issues.

Since this morning, the engine check light has been on, and the display shows 'Exhaust system - workshop!'

I read the error codes from the system.

001139 - Exhaust gas pressure sensor 1 (G450): Short circuit to positive terminal.
P0473 - 000 - - - Intermittent.
Environmental conditions:
Error status: 00100000
Error priority: 0.
Error frequency: 34
Mileage: 127305 km
Time: 0.
Date: 2000.00.00
Time: 11:15:59

Environmental conditions:
Speed: 0 RPM.
Speed: 0.0 km/h
Last: 0.0%
Voltage: 12.08 V
Mileage: 370 km
Temperature: 84.0°C
Pressure: 1744.2 mbar.

It seems like the differential pressure sensor is broken now too.
The wiring appears to be visually okay, at least.

The warning light didn't come on until 40 km later (at 127,345 km), shortly after a cold start. Why this delay?

Is it sufficient to just replace this sensor, or is an update of the engine control unit (ECU) required?

Most of the time, people are talking about the Passat, but in my case, it's a Golf 5 with the BLS engine.

I also read that the connection lines of the DPF should be blown out with compressed air.

What do you think?

Quote:

Is it sufficient to replace this sensor, or is an update of the engine control unit necessary?

Then you should also tell us which control unit and software version are involved.

Normally, if a sensor is defective, replacing it and recalibrating it is usually sufficient.
In theory, it's also possible that a weasel gnawed on the wiring causing the fault.

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.

Best regards, Rainer.

Software status: I hope you can make use of this information.

Address 01: Engine Control Module
Label file: DRV\03G-906-021-BLS.lbl
Control unit part number: 03G 906 021 HB. Hardware: 03G 906 021 HB.
Component and/or version: R4 1.9L EDC G000SG 9000.
Encoding: 0000071
Operating number: WSC 00028 028 00001.
VCID: 66DD786728E1

What does 're-calibrate sensor' mean?
Is a simple switch really enough?
It's just the sensor; it should only provide a voltage or current, or a resistance value.

Currently, the old differential pressure sensor, type 3G...xxx, is still installed.

I don't want to be taken advantage of by the friendly people.

I feel like I'm going to throw up.

Quote:

What does "re-calibrate sensor" mean?

Okay, I understand. Please provide the German text you want me to translate into English. I will only provide the translation.

In theory, no learning process would be necessary if the engine control unit is cleverly programmed.
Because you could use the "differential pressure" during a cold start/ignition as a reference point.

I don't know why they didn't do it, or if there are any reasons that would prevent them from doing so.

Quote:

It's just the sensor; it should only provide a voltage or current, or a resistance.

No. Please see my links.

Well, I was hoping that replacing the sensor would be enough.

Unfortunately, I only have a KEY-USB adapter from my old Golf 4.

Would that adjustment work?

Does the car run without any modifications? Or definitely not?

If not, I can go directly to the Volkswagen workshop and make an appointment.


Whether I would buy another diesel car is questionable.

If you can retrieve the ECU information, it will probably work...

Before anyone suggests getting a diagnostic system without CAN for the G5, it's likely that only the engine control unit is accessible via the K-line.
All G5 engine control units (ECUs) communicate exclusively via CAN bus, except for the R32 models, which seem to have an exception.

Hello everyone,


I've already read through all the posts related to this problem. I now understand how the sensor works and what steps should be taken for certain errors.
However, I couldn't find an answer to my specific problem.

Here's how everything started with my Passat 3C TDI 2.0, 140 hp, manufactured in 2006:
Approximately 2 weeks ago, I had an error code in the engine control unit: "Exhaust gas pressure sensor 1 (G450) - implausible signal."

After that, I replaced the differential pressure sensor and re-initialized it using VCDS. I cleared the error code beforehand.

Then there was about 10 days of peace. No more error messages.

After that, the engine check light came back on again.

The error log now showed:

Address 01: Engine Control Module
Label file: DRV\03G-906-021-BMM.clb
Control unit part number: 03G 997 021 J. Hardware version: 03G 906 021 MR.
Component and/or version: R4 2.0L EDC G000SG 3898.
Encoding: 0000072
Operating number: WSC 45497 142 83351
VCID: 30692F69A3A3F7C159-8064
3 error codes found:

009299 - Differential pressure sensor for diesel particulate filter.
P2453 - 000 - Implausible signal.
Environmental conditions:
Error status: 01110000
Error priority: 2
Error frequency: 1.
Lost Count: 255
Time: 0.

Environmental conditions:
Speed: 0 RPM.
Speed: 0.0 km/h
(no unit): 20.40
(no unit): 10.20
(no unit): 0.0
Temperature: 210.0°C
Temperature: 17.1°C

001138 - Exhaust gas pressure sensor 1 (G450).
P0472 - 000 - Short circuit to ground.
Environmental conditions:
Error status: 01110000
Error priority: 2
Error frequency: 1.
Lost Count: 255
Time: 0.

001137 - Exhaust gas pressure sensor 1 (G450).
P0471 - 000 - Implausible signal.
Environmental conditions:
Error status: 01110000
Error priority: 2
Error frequency: 1.
Lost Count: 255
Mileage: 306,410 km
Time: 0.
Date: 2017.05.24
Time: 17:44:40

Environmental conditions:
Speed: 1470 RPM.
Speed: 51.0 km/h
(no unit): -81.60
(no unit): 15.30
(no unit): 84.0
Temperature: 252.0 °C
Temperature: 20.7°C


Readiness: 1 1 0 0 0


I have deleted these errors. However, one remains.

Address 01: Engine Control Module
Label file: DRV\03G-906-021-BMM.clb
Control unit part number: 03G 997 021 J. Hardware version: 03G 906 021 MR.
Component and/or version: R4 2.0L EDC G000SG 3898.
Encoding: 0000072
Operating number: WSC 45497 142 83351
VCID: 30692F69A3A3F7C159-8064
Error codes have been cleared.

"One error found:"
001139 - Exhaust gas pressure sensor 1 (G450).
P0473 - 000 - Short circuit to positive.
Environmental conditions:
Error status: 01100000
Error priority: 2
Error frequency: 1.
Lost Count: 255
Mileage: 306,451 km
Time: 0.
Date: 2017.05.26
Time: 00:01:23

Environmental conditions:
Speed: 0 RPM.
Speed: 0.0 km/h
Last: 0.0%
Voltage: 12.39 V
Mileage: 160 km
Temperature: 12.0°C
Pressure: 969.0 mbar


I assume that the error message "implausible signal" is a consequence of a "short circuit to ground or positive voltage."

The error message "Short circuit to positive" cannot be cleared even when the pressure sensor connector is disconnected. Therefore, I suspect that there is a problem with the wiring or something further downstream.

Ich habe bereits die Leitung vom Sensor bis Steckverbindung (In der Nähe des Luftfilters) auf Kurschluss/Kabelbruch überprüft. AlOkay.
The wire from the plug continues into the wiring underneath the steering wheel. However, this section of the wire is fixed in place, and there's no visible damage on the outside. I believe that there shouldn't be any further issues with the cable itself.

I'm slowly running out of ideas. Can you give me one more tip?

Sure, no problem! Here's the translation:

"Thank you in advance!!"

Hello William,

When the ignition is turned on, the engine should be off, and the differential pressure sensor must read a pressure of 0.0 mbar, or at least result in zero when combined with its offset value.

If that's the case, either the sensor is faulty or there's a problem with the connector or wiring. I would check the cable for damage caused by rodents, as that area is particularly vulnerable.

Best regards, Rainer.

Hello Rainer,

Okay, after you reminded me about the pressure gauge, I observed it again while the engine was running. With the ignition on/engine off, the pressure gauge showed 0 bar (with offset). When the engine was idling, it still showed 0 bar. Then, I wiggled the cable directly in front of the pressure sensor's connector and watched the pressure gauge. It temporarily went up, and I was able to clear the error code.
Then I moved the cable again, and the error reappeared. Therefore, a broken wire is likely the cause. When I checked the wires for continuity, I probably had the cable in a position where the break was temporarily not present.

I will now try to replace the short section of cable from the connector towards the engine compartment. However, if the cable break is too close to the connector, I will probably have to buy a new connector with wiring.

Nevertheless, thank you very much, Rainer, for the quick response.

Thank you for your feedback!

The plug should actually be able to be disassembled because it's supposed to be similar to:
Okay, I'm ready. Please provide the German text you want me to translate into English.

It might take a little fiddling, but it should work with some patience.

Best regards, Rainer.

Hey, great! Thank you very much for the instructions!!!

Yes, that's a similar type of plug. I never would have thought this one could be disassembled.

Unfortunately, I won't be able to make it today. However, I will definitely try it out tomorrow and let you know how it goes.

Thank you very much, Rainer!

Okay, the thing with the plug worked perfectly thanks to your instructions, Rainer!

However, the error is still present: short circuit to positive.

It's definitely not a broken cable! I installed new cables directly from the plug to where they connect behind the motor, and I soldered them myself. I checked for continuity, and everything is fine.

If I unplug the sensor connector, the same error message appears.
Daher hatte ich vermutet, dass ich keinen richtigen Kontakt vom Stecker zum Sensor habe. Habe anschließend Leitungen direkt von den Pins des Sensors nach außen verlegt und mit dem Stecker verbunden. DThe error remained.


I suspect now that there's a loose connection in the pressure sensor. If that's the case, it's quite annoying because I recently bought a new sensor.

"Nevertheless, thank you, Rainer, for your advice!"

"No problem, the differential pressure sensor in your car outputs a voltage signal that is proportional to the pressure difference. The other two pins are ground and +5V."
You can easily test the sensor with a multimeter and check if the output signal is reasonable.

Best regards, Rainer.

Thank you, Rainer, for your tips!

Okay, I'm measuring 5V at pins 1 and 2; that's the power supply voltage.
Pin 3 is the sensor's output.

What I'm having trouble understanding right now is:

"Ignition on/Engine off, sensor connector disconnected."
Measurement at the output lead on pin 3 of the connector: 5.67 V.

Engine on, connector plugged into the pressure sensor.
Measurement at output pin 3: 4.97V.

In both cases, I have a pressure difference of 0 bar, including the offset.

What's confusing me is that I'm measuring 5.67 volts on the live wire at the outlet when the plug is disconnected. According to my understanding, there should be 0 volts there since the plug is unplugged.

Do you have any ideas?

The engine control unit (ECU) has an internal pull-up resistor for the input signal, which allows cable breaks to the sensor to be detected.

I don't know offhand what a voltage of "0 mbar" signifies. Besides a faulty sensor, if the reading is "short circuit to positive," it could also mean that the differential pressure within the DPF becomes excessively high during driving.
I've already encountered this issue at least with boost pressure sensors.

Ash mass and soot load from the DPF?

Best regards, Rainer.

The ash content is 8.0%, and the loading factor is 15%.

I was just watching a documentary about differential pressure sensors earlier.

Output signal of the pressure sensor: 0V corresponds to 0 mbar, and 5V represents the maximum mbar value.

So, in my case, it's essentially outputting the maximum voltage at the sensor's output.

Could the problem actually be due to an excessively high ash content?