C5, 2.2 Diesel Antipollution Code

[Guest REK]

Hi guys, hope you can help with 2004 (late series 1) C5 2.2 diesel manual estate, 50k one owner with full maintenance record.

Have the antipollution / ESP warning crop up several times over last several months, some 300 miles between faults appearing but seem to be getting shorter mileage between faults now.

Codes have been P1352 (noted each time), P0238 (noted 50% of time), P0234 (noted 50% of time). Motor is used mainly on longer hauls (50+ miles), generally lightly loaded.

Fault always appears under gentle acceleration and goes into limp mode most times.

Limp mode cancels after switching off once but error code / MIL on until either I have read and cleared faults with code reader or a dozen(ish) engine start ups.

So far have located broken swirl valve plastic rod connector (replaced with machined metal joint, rod moves under engine vacuum), removed and cleaned DPF, new EGR and cleaned out EGR pipework (which improved mpg by 20% on longer runs), checked all the numerous vacuum hoses, connections several times. Engine bay clean, correct oil used and changed recently, plenty of smooth power, perfect but for this occasional fault that is annoying the hell out of me !

[harry bozing]

Hi guys, hope you can help with 2004 (late series 1) C5 2.2 diesel manual estate, 50k one owner with full maintenance record.

Have the antipollution / ESP warning crop up several times over last several months, some 300 miles between faults appearing but seem to be getting shorter mileage between faults now.

Codes have been P1352 (noted each time), P0238 (noted 50% of time), P0234 (noted 50% of time). Motor is used mainly on longer hauls (50+ miles), generally lightly loaded.

Fault always appears under gentle acceleration and goes into limp mode most times.

Limp mode cancels after switching off once but error code / MIL on until either I have read and cleared faults with code reader or a dozen(ish) engine start ups.

So far have located broken swirl valve plastic rod connector (replaced with machined metal joint, rod moves under engine vacuum), removed and cleaned DPF, new EGR and cleaned out EGR pipework (which improved mpg by 20% on longer runs), checked all the numerous vacuum hoses, connections several times. Engine bay clean, correct oil used and changed recently, plenty of smooth power, perfect but for this occasional fault that is annoying the hell out of me !

Hi REK I have had a look oin my code list, p1352= ignition coil A primary circuit malfunction/ sid801 pre/post heatingrelay circuit-relay &pre-heat plugs not controlled. The p0238 and po234 codes I could not find listed. Hope this helps, regards, Brian.

[Guest REK]

Brian, Thanks for reply.

P1352 as you correctly say is pre / post heating relay but cannot see how this code relates to the fault, once engine is running would had thought the pre / post heat plug circuit would be out of the equation, fault only appears when engine is up to working temperature - anyone know different ?

Found a web site where code P0238 is given as 'turbo overboost sensor A circuit high' - anyone know what this means or what to check ?

Code P0234 apparently refers to 'turbo overboost condition' - can anyone know what this relates to and what to check ?

Seems codes are relating to turbo in some way - each time the code comes up it is as gentle acceleration is applied and probably around 1500rpm when I guess the turbo starts getting going, so thought it could be some vacuum control going outside it's designed parameters.

[Randombloke]

Code P0234 apparently refers to 'turbo overboost condition' - can anyone know what this relates to and what to check ?

 

This might be the manifold (absolute) pressure sensor sometimes referred to as MAP. Turbo overpressure used to be connected to the diesel pump by a thin hose but is now measured by a sensor. I'd treat this sensor as suspect if I could find it. It might be over reading.

 

That or there is a real problem cause by a jamming wastegate or similar. 2.2s have variable vanes turbos IIRC.

[Bassrock]

Brian, Thanks for reply.

P1352 as you correctly say is pre / post heating relay but cannot see how this code relates to the fault, once engine is running would had thought the pre / post heat plug circuit would be out of the equation, fault only appears when engine is up to working temperature - anyone know different ?

Found a web site where code P0238 is given as 'turbo overboost sensor A circuit high' - anyone know what this means or what to check ?

Code P0234 apparently refers to 'turbo overboost condition' - can anyone know what this relates to and what to check ?

Seems codes are relating to turbo in some way - each time the code comes up it is as gentle acceleration is applied and probably around 1500rpm when I guess the turbo starts getting going, so thought it could be some vacuum control going outside it's designed parameters.

 

 

I've had P1352 on my car for the last 2 years (Ok, it's the only code I've got listed, but car runs sweet), I therefore think you can forget about this one wrt your particular prob.

[Guest REK]

Bassrock, thanks for reply and I agree it may well be a red herring.

Have found the 'turbo sensor' on intercooler pipe (next to battery and in front of air filter box). Pipework in tact, no cracks / holes and electrical connector has clean and tight connection, no oil or gunge in pipe. When I disconnected this sensor i got warning up on dash and could read off code P0238 on scanner.

Have also read on a number of sites that the variable vanes on a turbo can get clogged up - VW and Audi have similar set up and appear to have an issue with this problem.

There are a few products on market claiming to clean the turbo - anyone know of this problem affecting Citroens or if any product is recommended (or not!).

Been on run today of 60 miles, no problems but felt as though driving through the gears at high rpm (up to 5000rpm) the engine performamnce felt flat when you changed up a gear until the turbo got going - could this be the vanes struggling to move easily. Don't normally drive hard but hoped to move some crude out of system with a bit of a thrash.

[Guest woodywoodpecker]

Hi guys, hope you can help with 2004 (late series 1) C5 2.2 diesel manual estate, 50k one owner with full maintenance record.

Have the antipollution / ESP warning crop up several times over last several months, some 300 miles between faults appearing but seem to be getting shorter mileage between faults now.

Codes have been P1352 (noted each time), P0238 (noted 50% of time), P0234 (noted 50% of time). Motor is used mainly on longer hauls (50+ miles), generally lightly loaded.

Fault always appears under gentle acceleration and goes into limp mode most times.

Limp mode cancels after switching off once but error code / MIL on until either I have read and cleared faults with code reader or a dozen(ish) engine start ups.

So far have located broken swirl valve plastic rod connector (replaced with machined metal joint, rod moves under engine vacuum), removed and cleaned DPF, new EGR and cleaned out EGR pipework (which improved mpg by 20% on longer runs), checked all the numerous vacuum hoses, connections several times. Engine bay clean, correct oil used and changed recently, plenty of smooth power, perfect but for this occasional fault that is annoying the hell out of me !

 

REK

I had the same fault as yours not had any faults since, look at my last post here

http://www.citroen-owners-club.co.uk/citroen/index.php?showtopic=8510&pid=41433&st=0entry41433