GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC P42 Commercial Chassis 🢒 Engine 🢒 Engine Controls - 6.5L (L57) 🢒 DTC P0225 Accelerator Pedal Position (APP) Sensor 3 Circuit

Object Number: 226926 Size: MF
Engine Controls Components L57 EFI
Engine Controls (Cell 22: Fuel Controls 5)
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 Setting the DTC
    • The reference voltage on the APP 3 is below 4.8 volts.
    • The condition was met for 2 seconds.

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 stores in the Failure Records.

Conditions for Clearing the MIL/DTC
    • A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle.
    • Use of a Scan tool will clear the DTC codes.

Diagnostic Aids

An intermittent may be caused by the following:

    • Poor connections
    • A rubbed through wire insulation
    • A broken wire inside of the insulation

All of the 5 volt reference circuits must be checked for a proper reference voltage. Voltmeter accuracy is important.

Test Description

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

  1. This step will check all 5 volt reference circuits.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing any DTCs, use the Scan Tool Capture Info to save freeze frame and failure records for reference, as the Scan Tool loses data when using the Clear Info function.

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

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

Is the voltage less than specified value?

4.8V

Go to Step 5

Go to Step 3

3

Are there any other APP DTCs set?

--

Go to the Applicable DTC Table

Go to Step 4

4

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

Are there any additional DTCs stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

5
  1. Turn the ignition OFF.
  2. Disconnect the PCM.
  3. Check the 5 volt reference circuit for a short to ground.
  4. If the 5 volt reference circuit is shorted to ground, repair as necessary.

Was the 5 volt reference circuit shorted to ground?

--

Go to Step 7

Go to Step 6

6

Replace the PCM.

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

Is the action complete?

--

Go to Step 7

--

7
  1. Using the Scan Tool, clear the DTCs.
  2. Start engine and idle at normal operating temperature.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle, within the Conditions for Setting this DTC, until the Scan Tool indicates the diagnostic Ran.

Does the Scan Tool indicate the diagnostic Passed?

--

Go to Step 8

Go to Step 2

8

Does the Scan Tool display any additional undiagnosed DTCs?

--

Go to the Applicable DTC Table

System OK