P2123-ACCELERATOR PEDAL POSITION SENSOR 1 CIRCUIT HIGH
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on.
- Set Condition:
The APP Sensor 1 signal circuit is above 4.6 volts for 0.32 seconds.
| Possible Causes |
| INTERMITTENT DTC |
| (K852) ACCELERATOR PEDAL POSITION SENSOR 1 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE |
| (K23) ACCELERATOR PEDAL POSITION SENSOR 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (K167) ACCELERATOR PEDAL POSITION SENSOR 1 SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE |
| (K23) ACCELERATOR PEDAL POSITION SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K852) ACCELERATOR PEDAL POSITION SENSOR 1 5 VOLT SUPPLY CIRCUIT OR (F856) ACCELERATOR PEDAL
POSITION SENSOR 2 5 VOLT SUPPLY CIRCUIT |
| (K852) ACCELERATOR PEDAL POSITION SENSOR 1 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE |
| (K23) ACCELERATOR PEDAL POSITION SENSOR 1 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| (K167) ACCELERATOR PEDAL POSITION SENSOR 1 SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE |
| ACCELERATOR PEDAL POSITION SENSOR |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. DTC IS ACTIVENOTE: If any Sensor reference or supply voltage DTCs are present, perform the applicable diagnostic procedure before continuing with this test.
NOTE: The APP Sensor is a device that contains two separate potentiometer type sensors. Each sensor has its own 5-volt supply circuit, sensor ground circuit and signal circuit. The APP Sensor no longer incorporates a low-idle switch.
NOTE: The APP Sensor 2 signal should always be approximately 1/2 the voltage of the APP Sensor 1 signal.
Ignition on, engine not running.
With the scan tool, clear DTCs in the Engine Control Module (ECM).
Fully depress and release the Accelerator Pedal several times.
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. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. ACCELERATOR PEDAL POSITION SENSOR CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Accelerator Pedal Position Sensor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the Main Relay.
Connect a jumper wire between cavity B7 and cavity B9 of the Main Relay Connector.
Turn the ignition on.
Measure the voltage of the (K852) Accelerator Pedal Position Sensor 1 5 Volt Supply circuit in the Accelerator Pedal Position Sensor harness connector.
Measure the voltage of the (K23) Accelerator Pedal Position Sensor 1 Signal circuit in the Accelerator Pedal Position Sensor harness connector.
Measure the voltage of the (K167) Accelerator Pedal Position Sensor 1 Sensor Ground circuit in the Accelerator Pedal Position Sensor harness connector.
Is there voltage present on any of the circuits?
Yes
- Repair the appropriate circuit that has voltage present.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 3
3. (K23) ACCELERATOR PEDAL POSITION SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE 5 VOLT SUPPLY CIRCUIT
Turn the ignition off.
Measure the resistance between the (K23) Accelerator Pedal Position Sensor 1 Signal circuit and the (K852) Accelerator Pedal Position Sensor 1 5 Volt Supply circuit in the Accelerator Pedal Position Sensor harness connector.
Measure the resistance between the (K23) Accelerator Pedal Position Sensor 1 Signal circuit and the (F856) Accelerator Pedal Position Sensor 2 5 Volt Supply circuit in the Accelerator Pedal Position Sensor harness connector.
Is the resistance above 10.0 ohms for both of the circuits?
Yes
- Go to 4
No
- Repair the shorted (K23) Accelerator Pedal Position Sensor 1 Signal circuit.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
4. ACCELERATOR PEDAL POSITION SENSOR CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (K852) Accelerator Pedal Position Sensor 1 5 Volt Supply circuit between the Accelerator Pedal Position Sensor harness connector and the Engine Control Module (ECM) harness connector.
Measure the resistance of the (K23) Accelerator Pedal Position Sensor 1 Signal circuit between the Accelerator Pedal Position Sensor harness connector and the Engine Control Module (ECM) harness connector.
Measure the resistance of the (K167) Accelerator Pedal Position Sensor 1 Sensor Ground circuit between the Accelerator Pedal Position Sensor harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms for each of the circuits?
Yes
- Go to 5
No
- Repair the appropriate circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
5. ACCELERATOR PEDAL POSITION SENSOR
Remove the jumper wire and install the Main Relay.
Connect the Engine Control Module (ECM) harness connector.
Connect a jumper wire between the (K167) Accelerator Pedal Position Sensor 1 Sensor Ground circuit and the (K23) Accelerator Pedal Position Sensor 1 Signal circuit in the Accelerator Pedal Position Sensor harness connector.
Turn the ignition on.
With the scan tool, Clear DTCs.
Fully depress and release the Accelerator Pedal several times.
With the scan tool, select View DTCs.
NOTE: The scan tool should display an Accelerator Pedal Position Sensor 1 low voltage or short to ground DTC with the jumper wire in place.
Does the scan tool display the DTC as described above?
Yes
- Replace the Accelerator Pedal Position Sensor in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 6
6. ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Accelerator Pedal Position Sensor and the Engine Control Module (ECM).
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.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Replace the Engine Control Module (ECM) in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)