C250cdi limp mode no Mil light?

[Tonygw]

Hi Team

I know it needs to be plugged into STAR but thought I would test the water here to see if anybody else has experienced this?

Car is 2012 S204 C250cdi OM651 with 131K on the clock.

recently a few times after a short drive the car feels like it goes into limp mode, but no engine light? power is lost and I need to put the throttle fully down to accelerate but will still get up to motor way speeds.

If I cycle the ignition off on, car resets and normal power is restored. For how long? I haven't had time to test properly. Had the car 5 years running mostly 10-20 mile round trips (school runs work etc) with at least one decent motorway run per month.

Any clues?

Cheers

 

[sautah]

I suspect you’ll find your DPF is at 400% fill level.
If you get your own code reader you’ll be able to see what’s up. Mine revolved around a failing 12v battery as the diagnosis / Regen history showed “battery level too love to complete “

New battery and a reset of the codes and a good run out with the live data showing and it was sorted.

Good luck

 

[Tonygw]

Thanks Sautah

Yep it was DPF related, the DPF pressure sensor was failing. Star diagnosis confirmed. New one now fitted.

Was very strange how I got no Mil light though,

Anyway, big thanks to MB automotive Loughborough.. They are flat out busy and booked up for weeks, yet they managed to fit mine in on a Saturday (when they are officially closed!) And at super short notice.

 

[DAMO71]

Thanks Sautah

Yep it was DPF related, the DPF pressure sensor was failing. Star diagnosis confirmed. New one now fitted.

Was very strange how I got no Mil light though,

Anyway, big thanks to MB automotive Loughborough.. They are flat out busy and booked up for weeks, yet they managed to fit mine in on a Saturday (when they are officially closed!) And at super short notice.

Hi, have you had any issues since the pressure sensor replacement? I’m having similar issues even after having DPF professionally cleaned

 

[sautah]

Hi, have you had any issues since the pressure sensor replacement? I’m having similar issues even after having DPF professionally cleaned

If you are having issues then there is still a fault present. In my opinion there's no need to have the DPF cleaned at all as once the actual fault is repaired and the codes are cleared the car will perform the regen.

 

[pcthrillrider2]

normally a dpf sensor throws a code ,a blocked dpf is P2463

 

[DAMO71]

Hi All, what are the steps to be taken when replacing the sensor?

 

[mersum1es]

Did you clean sensor pipes too? Car won't start regen is fill % is over 400% (different readers may give different range here, rely on SDS).... You may need to force regen or if you truly clened whole thing, tell ECU it has 'new' DPF fitted so it will reset values.