Carisma 1.9 Diesel 2002. Lack of power - Fixed!

[Geo]

Hi there.

Just got a 2002 Mitsubishi Carisma in. Symptoms are lack of power, particularly when pulling away from low revs. Once the turbo spools up it isn't so bad but at low revs the car is dangerously slow.

Anyway I plugged in launch and couldn't access the engine ECU through Mitsubishi. But these diesel Carismas have a Renault 1.9 DCI engine.

So I went in through Renault Megane and got the following code:

DF094 Thermoplunger memory relay N,open circuit or short circuit to earth.

There were no other codes.

Now I haven't got a clue what a thermoplunger is or if it would cause the symptoms this car is displaying 

Can anyone shed any light?

[Angus]

Geo

The thermoplungers are the immersion heaters that help warm up the heater.  Pretty usual code and not the problem.

Check the EGR valve isn't stuck open, or that it's head hasn't come off - DCi speciality.

[Geo]

Thanks for the reply Angus. I did some googling after posting the thread and realised that the thermoplunger code was unlikely to be the cause of the problem but thanks for the confirmation.

The EGR did give trouble on this car some months back and it was apparently removed completely.

I'll take a look at it tomorrow morning and see what exactly was done to remove it.

[Geo]

Ok the EGR is well and truly gone and blanked off so I doubt it is causing the problem.

I scanned the car again this morning and this time I got a MAF fault code:

DF019 Air flow sensor circuit, Coherence, engine running

Any ideas? Faulty MAF?

[Angus]

Geo

Coherence with engine running would suggest that there isn't a normal signal from the MAF at idle.

Measure it's voltage output and see what it's doing?

[Geo]

Thanks again Angus. Another thing I was thinking is that maybe there is an air leak on the inlet system after the MAF. That would also mean that the signal from the MAF would be seen as incorrect by the ECU?

[Geo]

Actually, I can read the MAF values from the live data using launch. Have anybody got an idea what a reasonable value should be so I have something to compare it to? I'm not too familiar with these cars.

[Geo]

I am getting 25 kg/h at idle. Does that sound about right?

[Angus]

Geo

Not too bad; what does it show revved hard?

[harveymotorcare]

Hi Geo,
Does this vehicle have a particle filter?
Regards Steve Harvey