Resolved 2014 Passat TDI - Multiple turbo trouble codes

[CapnMatt]

Took some time this evening to re-run the scans with the three different MAP sensors to compare readings. Significant differences between MAP sensors. I do notice that while completing the scans at idle the data reflects 000 engine RPM. That is not accurate as the engine IS running. Do you know what causes that? I would think I should see engine RPM listed correctly? Otherwise:

Sensor 1 Walker
1 Fault Found:
5168 - Altitude Sensor / Boost Pressure Sensor
P1592 00 [10100111] - Implausible Correlation
MIL ON - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 235114 km
Date: 2025.02.06.
Time: 09:26:10

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 36 C
Intake air temperature: 19 C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.800 V
Unlearning counter according OBD: 40
Charge air pressure: actual value: 2637 hPa
Engine status: COENG_READY
Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 1
_______________________________________________________________________

Sensor 2 OEM
1 Fault Found:
5170 - Manifold Pressure / Boost Sensor (G31)
P0237 00 [10101111] - Signal too Low
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 235114 km
Date: 2025.02.06.
Time: 08:36:10

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 29 C
Intake air temperature: 17 C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.040 V
Unlearning counter according OBD: 40
Charge air pressure: actual value: 200 hPa
Engine status: COENG_READY
Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 1

Readiness: 1 1 0 1 1

___________________________________________________________________________

Sensor 3 SMP
2 Faults Found:
5168 - Altitude Sensor / Boost Pressure Sensor
P1592 00 [10100111] - Implausible Correlation
MIL ON - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 235114 km
Date: 2025.02.06.
Time: 08:58:06

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 36 C
Intake air temperature: -40 C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.920 V
Unlearning counter according OBD: 40
Charge air pressure: actual value: 1182 hPa
Engine status: COENG_READY
Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 1

5282 - Intake Air Temp. Sensor (G42)
P0113 00 [10100111] - Signal too High
MIL ON - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 235114 km
Date: 2025.02.06.
Time: 08:58:06

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 36 C
Intake air temperature: -40 C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.920 V
Unlearning counter according OBD: 40
Exhaust gas temperature sensor 4: 52.7 C
Specified value of low pressure exhaust flap: 100.00 %
Actual value of low pressure exhaust flap: 100.01 %
Low-pressure exhaust flap: offset closed: 1.37 %
Low-pressure exhaust flap: status-Bits 0-7: 55
Low-pressure exhaust flap: status-Bits 0-7: 0
Low-pressure exhaust flap: status-Bits 0-7: 12
Low-pressure exhaust flap: status-Bits 0-7: 66
Exhaust flap: actual value: 4300.8 mV

Readiness: 0 0 0 1 1



SUMMARY: what do you all think? trying to learn from you all - It looks to me that sensors 1 & 3 are bad. If the OEM sensor is actually working correctly then we have an underboost problem. Maybe the bypass valve is bad?

 

[Dr Sheldon]

I'm shooting myself in the foot by purchasing non OEM sensors?

No shooting yourself in the foot with your diagnostic process

Your missing Schoolboy basics !!

5282 - Intake Air Temp. Sensor (G42)

Coolant temperature: 55 C
Intake air temperature: -40 C

Not saying that is the end of all your troubles !!

It is a nice easy fix !! It needs to be sorted as a Foundation to further testing !!

 

[SaVAGeSoot]

@Dr Sheldon
IAT & MAP are combined into a single sensor on that heap.

@CapnMatt
Use code tags. I've already explained to you why there's no RPM in the FF data.
You don't need to have engine on for these tests. Just ignition and scan.
You now need WDs.... it's starting to look like a potential wiring issue.

Lastly, had your ECU taken a shower or gone for a swim?

 

[CapnMatt]

Got it resolved. It was indeed the MAP. Swapped a brand new Bosch MAP and the car is back to normal. So the original assumption was correct. Stay away from any non OEM sensor. There were no issues with the wiring, ECU, vacuum solenoids, etc. All of the crazy codes were related to the different non-OEM MAPs.

 

[Uwe]

All of the crazy codes were related to the different non-OEM MAPs.

Common advice around here: If it has an electrical connector, buy it from the dealer, or from a reputable/trusted vendor that sells genuine parts.

-Uwe-

 

[SaVAGeSoot]

Huh? I thought #2 sensor was OEM! Was that a used OEM or what am I missing?

 

[Dr Sheldon]

Huh? I thought #2 sensor was OEM! Was that a used OEM or what am I missing?

Sensor 2 OEM

5170 - Manifold Pressure / Boost Sensor (G31)
P0237 00 [10101111] - Signal too Low
MIL ON - Confirmed - Tested Since Memory Clear

Engine RPM: 0.00 /min
Charge air pressure: actual value: 200 hPa = 0.2 BAR ??????

OEM means nothing anymore !
So much Counterfeiting going on now !

Most supply chains are corrupted now !! (UK)