Faulty Signal

ECM-9180 ACCELERATOR PEDAL (AP) POSITION SENSOR
FAULTY SIGNAL

Checking connectors
Check that the connector terminals for the accelerator pedal (AP) position sensor are OK. Check that there is voltage to the accelerator pedal (AP) position sensor from the fuse.

Checking status
Check the status to see if the fault is intermittent or permanent.
- Start the engine
- Press the accelerator pedal (AP) down at the same time as the brake pedal is depressed.

The fault is intermittent if the engine speed (RPM) increases.

The fault is permanent if the engine speed (RPM) does not increase.

Hint: Switch off the engine. Repeat the start procedure three times (to attempt to induce a permanent fault).

Note! In the event of an intermittent fault this is covered in the final check.

Is the fault permanent?
Yes - Continue below.
No - Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.


Reading off other diagnostic trouble codes (DTCs)
Note! If other diagnostic trouble codes (DTCs) such as ECM-9520/958F/959F/917F are stored, the wiring between the accelerator pedal (AP) position sensor and the engine control module (ECM) is faulty or the accelerator pedal (AP) position sensor is defective.

- Read off the other diagnostic trouble codes (DTCs). Check whether any of the specified diagnostic trouble codes (DTCs) have been stored.

Are any other diagnostic trouble codes (DTCs) stored?
Yes - Continue below.
No - Skip to "Checking accelerator pedal (AP) position sensor/engine control module (ECM)/electronic throttle module"


Checking components and wiring
Check the cable between engine control module (ECM) terminal #B25 (#B35) and accelerator pedal (AP) position sensor terminal #2. Check for an open-circuit. Check for a short-circuit to supply voltage or ground.

Remedy as necessary

Other information:
- To check the wiring, Checking Wiring and Terminals. Permanent Fault


Checking accelerator pedal (AP) position sensor/engine control module (ECM)/electronic throttle module
Check the cable between engine control module (ECM) terminal #A56 (#A56) and accelerator pedal (AP) position sensor terminal #1. Check for an open-circuit. Check for a short-circuit to supply voltage or ground.

Hint: If no fault is found in the wiring between the engine control module (ECM) and throttle unit the fault can be due to a defective accelerator pedal (AP) position sensor, defective electronic throttle module or defective engine control module (ECM).

Begin by trying a new accelerator pedal (AP) position sensor, then the electronic throttle module and finally the engine control module (ECM).

Note! Do not forget to reinstall fault-free components.
Remedy as necessary

Other information:
- To check the wiring, Checking Wiring and Terminals. Permanent Fault
- The signal from throttle unit terminal #2 is a pulse width modulated voltage of approximately Ubat and has a frequency of approximately 200 Hz.


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 approximately 7% when the accelerator pedal (AP) is unaffected and approximately 85% when the accelerator pedal (AP) is fully depressed.

Do the values correspond to movements of the accelerator pedal?
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.