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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy P32 RV/Van Chassis 🢒 Engine 🢒 Engine Controls - 6.5L (L65) 🢒 DTC P1125 Accelerator Pedal Position (APP) System

Object Number: 439258 Size: MF
Engine Controls Components
Cell 22: Engine Data Sensors and Wastegate Solenoid
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

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

Conditions for Running the DTC

The ignition switch in the on position.

Conditions for Setting the DTC

The PCM has recognized an intermittent APP fault and there are no other current APP faults stored.

Action Taken When the DTC Sets
    •  The Service Throttle Soon lamp will not illuminate when one APP DTC sets. The PCM will only illuminate the Service Throttle Soon lamp when multiple APP DTCs set.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Failure Records.

Conditions for Clearing the MIL/DTC
    • A History DTC will clear after forty consecutive engine warm up cycles, if this or any other emmision related diagnosic does not report any failures.
    • Use of a scan tool will clear the DTC codes.

Diagnostic Aids

There are no driveability issues associated with the APP module unless a DTC is present. The most likely cause of this DTC are poor connections or the sensor itself. The least likely is a PCM problem.

A DTC P1125 will set along with multiple APP DTCs. All other DTCs should be diagnosed first.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step determines if DTC P1125 is a hard failure or an intermittent condition.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing any DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure records for reference. The control module's data is deleted once the Clear Info function is used.

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Disconnect the APP sensor electrical connector.
  2. Ignition ON, engine OFF.
  3. With J 39200 DMM connected to ground, check all APP 5 volt reference circuits at APP harness.

Is voltage less than specified value?

4.8 V

Go to Step 4

Go to Step 3

3

DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored refer to the applicable DTC table(s) first.

Are any additional DTCs stored?

--

Go to the applicable DTC table

Go to Diagnostic Aids

4
  1. Turn the ignition switch OFF.
  2. Disconnect the PCM and check the 5 volt reference circuit for a short to ground.
  3. If the 5 volt reference circuit is shorted to ground, repair it as necessary. Refer to Wiring Repairs .

Was the 5 volt reference circuit shorted to ground?

--

Go to Step 6

Go to Step 5

5

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 6

--

6
  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the engine reaches normal operating temperature.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number which was set.
  6. Operate the vehicle, with the Condition for Setting this DTC, until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

--

Go to Step 7

Go to Step 2

7

Does the scan tool display any additional undiagnosed DTCs?

--

Go to the applicable DTC table

System OK