Megane 2 cc throttle problem - DF008

[e5rthuj]

Hello,
My Megane 2 cc 1.9 dCi behaves quite sluggishly for its 120hp. Between 1000 and 2000 rpm no matter how strongly I press the throttle pedal the car accelerates only gradually and sluggishly. The car is much more responsive above 2000 rpm and can easily reach high speeds.

Initially I thought the problem was with the injection because on startup it shows "Check injection". However. the message disappears after a short drive but the Service light remains lit.

The diagnostics in the garage showed the following errors:
- DF008 Pedal potentiometer circuit track. Jammed accelerator pedal detected
- DF017 Preheating unit control circuit open circuit
- DF025 Preheating unit diagnostic connection

The garage told me the throttle pedal is to be replaced and this is what's causing the lack of acceleration. They said the other errors require the glow plugs and the glow relay to be replaced. The latter two errors supposedly caused the "Check injection" message and had an effect on the car only with startup at negative temperatures, so nothing to do with acceleration.

Reading online I am concerned the problem might not be the pedal itself but the wiring between the pedal's potentiometer and the ECU. Are there schematics online which can help me measure the resistance and volts on the different wires coming to the pedal? I already took the pedal off but I am not sure what and where to measure.

By the way, the external temperature sensor shows wrong temperatures. It claims -37C when it is around 10C. Could this be causing the glow plugs errors?

Any advice on how to proceed is very welcome!

[CptEgert]

Hey, I also have a code DF008

Problem with Pedal potentiometer, did replacing the pedal work. Or was wiering bad/corroded somewhere?

What fixed the problem?

[e5rthuj]

Hi, I replaced the pedal and as far as I remember it fixed the error code. It’s an easy job involving only 2-3 bolts. The pedal was from an automatic car with a kick-down but it worked perfectly and only cost £25.

The loss of power though was due to a bad mass flow sensor.
Good luck!