GM/Detroit 6.5L ENGINE CONTROLS – DTC P0225 APP Sensor3 Circuit

Circuit Description
The accelerator pedal position (APP) module provides a voltage signal that changes relative to accelerator pedal position. There are three sensors located within the APP module that are scaled differently.

Conditions for Running the DTC
• The PCM performs this DTC diagnostic continuously.
• The ignition switch in the ON position.

Conditions for Setting the DTC
• The reference voltage on the APP 3 sensor is less than 4.8 volts.
• All of the diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets
• The PCM will turn ON the Service Throttle Soon lamp and limit power.
• Multiple DTCs will be present.

Conditions for Clearing the MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures
• The use of a scan tool.

Diagnostic Aids
An intermittent may be caused by the following:
• Poor connections
• Rubbed through wire insulation
• Broken wire inside the insulation
All 5 volt reference circuits must be checked for proper reference voltage. Voltmeter accuracy is important.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. This step will check all 5 volt reference circuits.


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