Technical Jeep compass with Fiat 2 litter multi-jet engine

[Jowel]

Dear Team,
I am seeking your assistance in resolving an issue with my Jeep Compass, which is equipped with a 2.0L Fiat Multijet diesel engine. The vehicle has clocked 150,180 km on the odometer and has been maintained regularly as per the routine schedule.
Recently, the car started displaying a Check Engine warning on the dashboard, accompanied by limp mode activation. Upon diagnosing the issue with a diagnostic tool, the following error code was retrieved:
• P0238: Positive boost pressure governor deviation (low pressure, signal calculation failure). Description: Turbocharger control positive drift (low pressure) - signal calculation failure (active), warning lamp triggered by the Power Train Module (DIESEL).
I conducted a thorough inspection of the entire inlet network but found no leaks. The maximum pressure reading I observed was 220 kPa in 4th gear at 110 km/h, leading me to believe that there are no signs of a weak turbocharger.
Also noticing that the p0238 will reappear if the vehicle in low speed under 3rd and 4th gear if it is climbing heights
After driving a few hundred kilometres,(mean while I cleared the p0238 and I controlled the driving pattern means not to too stress the vehicle ) another error code started appearing, related to the DPF system (the vehicle is fitted with a DPF but does not have AdBlue requirement ):
• P2455: DPF Pressure Sensor Circuit High.
However, all reference data appears to be within permitted levels. You can see the attached output for reference.
One peculiar behaviour I noticed is that clearing the P2455 code causes it to reappear within 90 seconds, regardless of whether the engine is idling or running at higher RPMs (tried at 1500 RPM and 2500 RPM).
I would greatly appreciate your guidance on how to proceed with diagnosing and resolving these issues.

 

[bugsymike]

No claims to be diagnostic expert, however I had a P0238 which in the end was an air leak on inlet manifold where EGR pipe connects, but that gave black smoke then would go to limp mode and you say "I conducted a thorough inspection of the entire inlet network but found no leaks" so probably rules that out.
Another thing is the 70.98% Soot mass and also the "Forced Regen Terminated Successful...No.
This would make me suspicious of a DPF issue, especially if your driving is generally short low speed town usage?
If that is the case maybe try a DPF cleaner additive at next fill up of diesel, then with a warm engine do a decent run for around 30 miles with about 2000-3000rpm without stopping.
I have had that work on other makes of vehicle.

 

[porta]

Does the engine, front left side looking at it, make a slight buzzing noise after switching off?

 

[Jowel]

Does the engine, front left side looking at it, make a slight buzzing noise after switching off?

No

 

[Jowel]

No claims to be diagnostic expert, however I had a P0238 which in the end was an air leak on inlet manifold where EGR pipe connects, but that gave black smoke then would go to limp mode and you say "I conducted a thorough inspection of the entire inlet network but found no leaks" so probably rules that out.
Another thing is the 70.98% Soot mass and also the "Forced Regen Terminated Successful...No.
This would make me suspicious of a DPF issue, especially if your driving is generally short low speed town usage?
If that is the case maybe try a DPF cleaner additive at next fill up of diesel, then with a warm engine do a decent run for around 30 miles with about 2000-3000rpm without stopping.
I have had that work on other makes of vehicle.

Thank you for pointing out the soot quantity. I restarted the forced regeneration using the Multiecuscan software with the vLinker FS Bluetooth adapter. After performing the procedure, the soot mass reduced to 11%, and I cleared all error codes. Following this process, the vehicle stabilized, and its performance was restored. Additionally, the P0238 error has not reappeared.

 

[bugsymike]

Thank you for pointing out the soot quantity. I restarted the forced regeneration using the Multiecuscan software with the vLinker FS Bluetooth adapter. After performing the procedure, the soot mass reduced to 11%, and I cleared all error codes. Following this process, the vehicle stabilized, and its performance was restored. Additionally, the P0238 error has not reappeared.

Sounds right direction.
I would still use the DPF cleaner additive in fuel regularly and the method I suggested.

 

[Jowel]

Sounds right direction.
I would still use the DPF cleaner additive in fuel regularly and the method I suggested.

Yes that is one of the regular thing I should do I already ordered liqui moly dpf cleaner and waiting for the delivery

 

[porta]

Well the wife’s car is fixed and now behaving itself, it was the EGR and, apparently, can set off random faults everywhere…well done to Turin Motors, Leeds, again for a great result