View source for 18047/P1639/005689

== 18047/P1639 - Accelerator Position Sensor 1/2 (G79/G185): Implausible Signal ==

==== Possible Symptoms ====

* Malfunction Indicator Light (MIL) ON 
* Reduced Engine Output

==== Possible Causes ====

* Wiring Harness from Accelerator Pedal to ECM
* Faulty ECM
* Faulty Accelerator Pedal

==== Possible Solutions ====

* Check Measuring Block Readings for Accelerator Pedal
* Check Voltage Signals from ECM to Throttle Pedal (see factory repair manual)
* Check Wiring and Connectors from Accelerator Pedal to ECM

==== Special Notes ====

* There are 2 sensors in the accelerator pedal, both measure the same except that they are working in opposite directions. This means one counts from 0 to 100, while the other one counts from 100 to 0. 

* Accelerator Position Sensor faults can be caused by issues with the Oxygen Sensor(s) and it's wiring.  Please verify this '''BEFORE''' replacing the ECM or Accelerator Pedal.  Accelerator Pedal failure is very rare.



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[[Category:Fault Codes]]