Signal Too Low - Permanent Fault

ECM-9520 ACCELERATOR PEDAL (AP) POSITION SENSOR, FAULTY SIGNAL
SIGNAL TOO LOW - PERMANENT FAULT

Checking component and wiring






Check accelerator pedal (AP) position sensor connector for defects, incorrect installation etc.

Check cable between engine control module (ECM) # B25 (# B35) and accelerator pedal (AP) position sensor # 2 for a short-circuit to supply voltage according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check cable between engine control module (ECM) # B25 (# B35) and accelerator pedal (AP) position sensor # 2 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check the power supply cable between accelerator pedal (AP) position sensor # 1 and the fuse (see the wiring diagram) for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault also check that the fuse has not blown.

Check the ground lead between accelerator pedal (AP) position sensor # 3 and the ground terminal (see wiring diagram) for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Remedy as necessary

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the accelerator pedal (AP) position sensor, Accelerator Pedal Module, Replacing
- The signal from accelerator pedal (AP) position sensor # 2 is a pulse width modulation (PWM) signal, # 2 is power supply (12V) and # 3 is the ground terminal.
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


Verification



Hint: After carrying out the repair, check that the fault has been remedied.

- Ignition off.
- Reinstall connectors, components etc.
- Ignition on.
- Read of the pulse modulated signal. Try depressing and releasing the accelerator pedal (AP). The value is between 6-9% when the accelerator pedal (AP) is unaffected and 85-90% when the accelerator pedal (AP) is fully depressed.

Do the values correspond?
Yes - Testing Complete.
No - Continue below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault tracing for this diagnostic trouble code (DTC) or make another attempt.