GPEC

P2138-ACCELERATOR PEDAL POSITION SENSOR 1/2 CORRELATION

For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on, battery voltage greater than 10.4 volts, and no APPS 1 and APPS 2 DTCs present.

- Set Condition:
The PCM detects that the correlation between APPS 1 and APPS 2 is not plausible. Idle may be affected when the brake pedal is pressed or if a brake switch circuit error is present. Acceleration rate and engine output are limited. One trip fault and the code will set within 5 seconds. ETC light is flashing.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

Diagnostic Test

1. DTC IS ACTIVE

NOTE: Diagnose and repair any APPS, system voltage, or sensor supply voltage DTCs before continuing with this test.

Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

With the scan tool, select View DTCs.
Is the status Active for this DTC?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC

2. (K855) 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

Turn the ignition off.
Disconnect the Accelerator Pedal Position Sensor connector.
Disconnect the Powertrain Control Module (PCM) connector.

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.

Measure the resistance of the (K855) 5 Volt Supply circuit between the Accelerator Pedal Position Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 3

No

- Repair the (K855) 5 Volt Supply circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.

3. (K23) APP SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.

Measure the resistance of the (K400) APP Sensor Ground 2 circuit between the Accelerator Pedal Position Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 8

No

- Repair the (K400) APP Sensor Ground 2 circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.

8. ACCELERATOR PEDAL POSITION SENSOR VOLTAGE
Turn the ignition off.
Connect the Accelerator Pedal Position Sensor connector.
Connect the Powertrain Control Module (PCM) connector.
Turn the ignition on.
Set up a lab scope to view two graphs simultaneously.
Using one channel on the lab scope, backprobe the (K23) APP Signal 1 circuit at the APP Sensor harness connector.
Using the other channel on the lab scope, backprobe the (K29) APP Signal 2 circuit at the APP Sensor harness connector.
Slowly press and release the Accelerator Pedal while monitoring the lab scope screen.
Does the scope pattern show any missing or erratic signals?

Yes

- Go to 9

No

- Go to 10

9. ACCELERATOR PEDAL POSITION SENSOR
Turn the ignition off.
Inspect the wiring and connectors between the Accelerator Pedal Position Sensor and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.

No

- Replace the Accelerator Pedal Position Sensor.
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.

10. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Accelerator Pedal Position Sensor and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test Ver. 1Powertrain Verification Test.