What does fault code ECM-P21252F mean?

Diagnostic fault code details for ECM-P21252F (Volvo S60 (2011–), Volvo S80 (2007–), Volvo S80 (2007–)). Repair service at OBD Tuning.

VOLVO

ECM-P21252F - Throttle/Pedal Position Sensor/Switch E Circuit. General Signal Failures. Signal erratic

System

Engine Control Module (ECM)

Volvo models this fault code applies to

Applies to the following models:

3 models

S60 (2011–), S80 (2007–), V70 (2008–)

Show models by year and engine (9)

What does this fault code mean?

The central electronic module (CEM) has sent a fault message to the engine control module (ECM) reporting that the accelerator pedal signal is erratic. The signal itself may be unstable, or the CAN communication between the modules may be faulty. This is a follow-on code from CEM, so the CEM fault should be fixed first and this code erased afterwards.

Possible causes

Unstable signal from the accelerator pedal sensor
Fault in the central electronic module (CEM)
Fault in the CAN communication between CEM and the engine control module

What you can do

1Read the fault codes in the central electronic module (CEM) first, as the root fault is there
2Troubleshoot and fix the CEM faults as needed, starting with fuses and connectors
3Erase the code in the engine control module once the CEM faults are gone, then road test the car to check that it does not come back
4If you have a diagnostic tool, check whether the accelerator pedal value in live data jumps or stutters as the pedal is moved slowly up and down

Symptoms you may notice2

Poor response from the accelerator pedal
Cruise control does not work at all

What the fault can affect1

The accelerator pedal is out of action when the brake pedal is pressed

General guidance for car owners. Diagnosis on the car can point to a different cause.