2015 DS3 - service light limp mode

[Jonathangaillard]

Hi
I am hoping someone can help me here. My son has a DS3 1.6 diesel and it initially came up with the engine light staying on and a message on the screen saying 'engine fault'. After a few minutes of driving once the engine seemed to get warm, the Service light would come on and it would remain in limp mode.

I took to a local garage to have it scanned and it came up with P2562 Turbocharger: Position incorrect relative to required. Not enough Turbo.

After doing some investigation it seemed from forums that the Turbo pressure Solenoid valve could be the problem. Part number 9811643880. So I replaced it today with a genuine PSA part.

We now have a totally different outcome. When you start the engine the engine light goes out as it should and there is no message of a fault on the cars screen. Initially the car drives without issue however after a few minutes - seems to be when the car has got up to temperature Service light comes on an it goes straight into limp mode (still not engine warning light on). I have been to the garage this afternoon and the only codes present are:
P0694 - Engine Cooling fan unit: Short circuit to positive or open circuit on the fan assembly control 2
P0495 Electric Cooling Fan unit. Twin Speed, Incoherent between the reference value (high speed) and the status of the fan assembly.

The garage have said it could be the MAF however I would expect to see a code pointing in this direction. I also cannot see how a fault with the fan could cause it to go into limp mode.

If anyone has experienced such an issue in the past like this i would really appreciate some pointers!
Many Thanks
Jonathan

[GiveMeABreak]

Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff. Then I can relate the faults directly to the correct engine ECU.

[Jonathangaillard]

Hi Marc. The VIN is VF7**************[VIN obfuscated, can be read by forum staff]
Thanks for your help

[GiveMeABreak]

Here's the relevant descriptors for those fault codes as they relate to your engine management system:

Fault Code:	P2562
Description of Fault:	Turbocharger: Position incorrect relative to requirement, not enough turbo. The position measured is greater than the reference by more than 20 % for 4 seconds. Conditions of activation of the diagnostics The following conditions have to be met: - engine running - Engine speed between 1500 and 4000 rpm
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	-
Symptoms:	Noise Smoke from the exhaust Lack of power Loss of braking
Suspect Areas:	Turbocharger Turbocharger fixed geometry control electrovalve Turbocharger fixed geometry position repeat sensor EGR exchanger with bypass EGR exchanger bypass control solenoid valve Vacuum pump Electrical harnesses

Fault Code:	P0694
Description of Fault:	Electric cooling fan unit: Short-circuit to positive or open circuit on the cooling fan control 2. Electrical fault detected for 5 s.
Conditions for Fault to clear:	Engine running hot for 5 minutes with the cooling fan activated
Downgrade Modes whilst Fault is active:	-
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light Absence of automatic stopping of the internal combustion engine (Vehicle equipped with "stop and start")
Suspect Areas:	Fan assemblies Fuse Electrical harnesses Connectors

Fault Code:	P0495
Description of Fault:	Dual speed Fan Assembly : Incoherence between the reference value (high speed) and the status of the fan assembly. Incoherence between the reference value (high speed) and the status of the fan assembly (For 5 seconds).
Conditions for Fault to clear:	Driving for 5 minutes from a cold engine, until the coolant temperature reaches 90°C
Downgrade Modes whilst Fault is active:	Deactivation of the particle filter regeneration forced by the diagnostic tool Switching on of the warning lamp and/or warning message: "SERVICE" warning lamp
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light Absence of automatic stopping of the internal combustion engine (Vehicle equipped with "stop and start")
Suspect Areas:	Fan assembly Electrical harnesses Connectors

[Jonathangaillard]

Hi
Thanks for putting up the full details of the fault codes i mentioned. Once I replaced the Turbo Pressure Solenoid, cleared and rescanned only two codes remain:
P0495 & P0694 which both seem to relate to the cooling fan and once the car seems to get to temperature, the SERVICE light comes on and it goes into limp mode.

Looking at the fault descriptions the only one that references SERVICE light coming on is P0495. I also dont think the start stop is working as the green ECO light seems to flash when you first start the car. So I guess i need to look at Fan assembly, Electrical Harness and Connectors?

Can anyone give me some tips on how to check this? What is the fuse location for the fan? Can i test the fan with a 12v source to ensure it works?

Any help appreciated.
Thanks
Jonathan

[Jonathangaillard]

I should add something further.. Maybe totally irrelevant but may be something.

My son has just mentioned that up until a few months ago when he got home he would get out the car and the fans would occasionally be running for 5-10 minutes. He only has a circa 3 mile drive from school therefore I wouldn't expect it to be because the engine got too hot during such a short journey. The fans have not come on when he has got home from school for the past 3 or 4 months.

Could this be related to anything experienced?

[PaulC5]

The engine fan being on could mean it was doing a regen of the DPF when the engine was switched off.

[Paul-R]

Or that air conditioning was switched on.

[Jonathangaillard]

Or that air conditioning was switched on.

Just for clarity: Would the fan continue to run after the engine had been switched off if the Air Conditioning had been in use?

[Jonathangaillard]

The engine fan being on could mean it was doing a regen of the DPF when the engine was switched off.

Thanks Paul. How often would you expect it to do a DPF regen? 5 days a week it does very short runs (like 6 miles a day) and then longer approx 15 miles on a Saturday? If it hasnt done a regen for a few months will it cause any issues? I guess if the fan isnt working then it cant do a DPF regen..

Any ideas on how to test the fan? Is there a specific fuse i should be checking? Are there any known issues i should be looking for? Is there a way of introducing a 12v source to test the fan works or a mulitmeter test?

Thanks for your help,

[Paul-R]

Just for clarity: Would the fan continue to run after the engine had been switched off if the Air Conditioning had been in use?

I honestly don't know. Certainly if the engine is hot but if it's barely at working temperature...?

[PaulC5]

I think the DPF regen history can be checked with a diagnostic as well as how blocked it is.
The fan running when the air con is on might be switched by the refrigerant pressure rather than engine temperature. When the engine is switched off the compressor will not be running so the pressure will drop and the fan not be needed.

[Jonathangaillard]

Thanks for all the replies. I think the first thing i need to confirm is if the fan is working or not as this is 1) what the fault code P0495 points to the fan assembley and 2) if the fan is not working it wont do DPF regen anyway - not that i have a fault for anything DPF related currently.

Any tips on how to test the fan? Is there a specific fuse that could have gone? Any help appreciated

[GiveMeABreak]

When they go, they go. Water can get into the fan electronics and cause corrosion or just general internal failure. Check all the connections on the fan assembly (but beware the fan can engage with the engine and ignition switched off!). As per the code guide in my previous post, there's not much else to check apart from the electrical connection, the harness. At least the control unit is available separately.

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[Jonathangaillard]

Hi All
I just thought i would post a bit of an update with this post. The final issue was that as soon as the car got up to temperature is would go into limp mode and would remain in limp mode until the car cooled again. After testing the fan and a few other bits I tried testing the Radiator Fan Resistor. Now i would get different resistance readings across the 4 pins which are obviously the outputs to switching fan etc so in essence you would think it was testing Ok, however figured that with no other potion i would just buy a cheap one of amazon and see what the readings were like on that.

The readings were totally different therefore i put it on. Cleared the fault! Been on some long drives to fully test and it seems to have done the job. It was only a £15 part for the dodgy amazon one so dont know how long it will last but we will see. Part number 9662872380

Car has not done a DPF regen for a long time now, hopefully it will just do one shortly unless there is a way i can force a regen??

Anyway fingers cross issue now resolved

Cheers all