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Home >> Cadillac >> 2005 >> XLR >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (DTC P0638 To P2095) >> DTC P0641 >> Test Description
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Test Description

The number below refers to the step number on the diagnostic table.

  1. 5:  This step will determine if the APP sensor 1 is at fault, or if another device or circuit condition is at fault.
DTC P0641

Step Action Values Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 3  Go to Intermittent Conditions
3
  1. Turn OFF the ignition.
  2. Disconnect the accelerated pedal position (APP) sensor electrical connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the 5-volt reference circuit of the APP sensor 1 harness connector to a good ground with a DMM.
Is the voltage within the specified range?		 4.8-5.2 V Go to Step 5  Go to Step 4 
4 Is the voltage more than the specified value? 5.2 V Go to Step 8  Go to Step 6 
5 
  1. Connect the APP sensor electrical connector.
  2. Disconnect the manifold absolute pressure (MAP) sensor.
  3. Measure the voltage from the 5-volt reference circuit of the MAP sensor harness connector to a good ground with a DMM.
Is the voltage within the specified range?		 4.8-5.2 V Go to Intermittent Conditions Go to Step 9 
6
  1. Monitor the DMM while disconnecting all other devices connected to this 5-volt reference circuit one at a time.
  2. If the voltage changes when one of the components is disconnected, replace the component. Refer to the appropriate replacement procedure.
Was a component replaced?		 - Go to Step 11  Go to Step 7 
7 Test this 5-volt reference circuit for a short to ground or a short to any sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct a condition?		 - Go to Step 11  Go to Step 10 
8
  1. Turn ON the ignition, with the engine OFF.
  2. Test the following circuits for a short to voltage:
Did you find and correct a condition?		 - Go to Step 11  Go to Step 10 
9 Replace the APP sensor. Refer to Accelerator Pedal Position (APP) Sensor Replacement .
Did you complete the replacement?		 - Go to Step 11  -
10 Replace the engine control module (ECM). Refer to Control Module References in Computer/Integrating System for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 11  -
11
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 12 
12 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK
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