C5 X7 THP -11 Running rich? Codes P2279 & P0134. Suspension and Engine Cooling fan

[Sami_R]

I managed to get hydraulic pump going, but it blows the fuse again. Also rear end of the car raises too high and it is rock solid when driving. Is it possible that sensor is bad in rear axle? Sensor looks old but that little arm is new.

When I turn off the engine, pump is sounding like it’s going really slow and struggling to spin. But I don’t know how it is supposed to sound when it is okay.

[GiveMeABreak]

Great one problem down at least!

[Sami_R]

Update.

Cooling fan is now working properly. It was resistor located in fan housing. I switched it to a new one and it started working fine.

[Sami_R]

…about the check engine light. The car is obviously running rich. Exhaust gas smells like it is not burning all the fuel properly. I checked the fuel trim with scan tool and short term fuel trim is high negative, about -15 to-20. Upstream oxygen sensor is showing 0,020v to 0,6v. I’m thinking if it is upstream lambda or MAP sensor?

[Sami_R]

Downstream oxygen sensor is showing steadily about 0,450v - 0,455v.

[Sami_R]

Hi, good news aout suspension. It is working again. Rear ride height sensor was so far off from its right position that it was the reason why rear suspension was topmost position all the time and asking for more from hydraulic pump. I guess that was the reason why pump blow the fuse eventually. I have now adjusted the rear ride height about the right position by the eye. It seems to work and no more blown fuses so far. I guess it needs to be fine tuned later.

There is still one problem with the engine, but I think i'm starting new topic about that. Suspension and cooling fan is okay so far. Thanks for your support.

[Sami_R]

Hi all,

My new to me Citroen is giving me grey hair to understand why it is not happy. Here is what I have noticed so far, if somebody can give me a hint what to check next?

- Error codes P2279 & P0134
- "Engine fault repair needed"
- SERVICE light on dash all the time
- Sometimes engine light, but I can reset it by erasing error codes
- Exhaust gas is smelling like it is running rich
- Yesterday I was changing the oil to the car and old oil was smelling fuel really much. (It was probably very old also)
- Little bit long start. I do not know if it is normal or not?
- Engine is running little too cold. About 75c when driving and when idling about 85c. (I think it should be about 100c when normal)
- Short therm fuel trim is sometimes high negative. About -15 to -20% when idling and engine temperature ~80c.

Done so far:

- Try to find some air leak from the intake and other pipes (no luck)
- Changed the intake manifold pressure sensor (no change)
- Changed the MAP sensor (no change)

What I'm thinking:

- Can thermostat be bad and cause the running rich condition or is the low temp just because the car is sensing something is wrong (like safe mode)?

[Paul-R]

You haven't mentioned the air intake filter. Has it been checked and/or replaced?

[Sami_R]

You haven't mentioned the air intake filter. Has it been checked and/or replaced?

Hi Paul-R,

intake filter is new, clean and original part.

[Sami_R]

I forgot to mention that the Upstream lambda voltage is changing between 0,020V to ~0,6V.

[Paul-R]

What was the condition of the old filter?

[Sami_R]

What was the condition of the old filter?

I do not know. I was bought the car like this. I guess the previous owner have tried to solve this case already and put the new filter in.

I wonder if the upstream lambda is bad because there is error code for that? But how to diagnose it?

[Sami_R]

Which pins are for heater function in upstream lambda connector plug?

[GiveMeABreak]

I have merged this topic with the existing topic that related to some of these faults to avoid duplication. Please keep everything related to these issues and fault codes on THIS thread.