P2127

P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW

For a complete wiring diagram, refer to the Wiring Information. Electrical Diagrams

- When Monitored:
With the ignition on and the battery voltage greater than 10.4 volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the Accelerator Pedal Position Sensor input voltage is below the minimum acceptable value. One trip fault. Three good trips to turn off the MIL. ETC light is flashing.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE
1. 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 hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.

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

2. With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.

2. (F856) 5-VOLT SUPPLY CIRCUIT VOLTAGE

1. Turn the ignition off.
2. Disconnect the Accelerator Pedal Position Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F856) 5-volt Supply circuit in the Accelerator Pedal Position Sensor harness connector.

Is the voltage above 4.5 volts?

Yes

- Go To 5

No

- Go To 3

3. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

1. Turn the ignition on.
2. Disconnect the Powertrain Control Module (PCM) harness connector.
3. Measure the resistance between ground and the (F856) 5-volt Supply circuit in the Accelerator Pedal Position Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 4

No

- Repair the (F856) 5-volt Supply circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

4. (F856) 5-VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) harness connector.
3. Measure the resistance between ground and the (K29) APP Signal 2 circuit in the Accelerator Pedal Position Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 6

No

- Repair the (K29) APP Signal 2 circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

6. (K29) APP SIGNAL 2 CIRCUIT SHORTED TO THE (K167) APP SENSOR GROUND 1 CIRCUIT

1. Measure the resistance between the (K29) APP Signal 2 circuit and the (K167) APP Sensor Ground 1 circuit in the Accelerator Pedal Position Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 7

No

- Repair the (K29) APP Signal 2 circuit for a short to the (K400) APP Sensor Ground 2 circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

7. (K29) APP SIGNAL 2 CIRCUIT SHORTED TO (K400) APP SENSOR GROUND 2 CIRCUIT

1. Measure the resistance between the (K29) APP Signal 2 circuit and the (K400) APP Sensor Ground 2 circuit in the Accelerator Pedal Position Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 8

No

- Repair the (K29) APP Signal 2 circuit for a short to the (K400) APP Sensor Ground 2 circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

8. (K29) APP SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.

1. Measure the resistance of the (K29) APP Signal 2 circuit between the Accelerator Pedal Position Sensor harness connector and the appropriate terminal of PCM Pinout Box 8815.

Is the resistance below 5.0 Ohms?

Yes

- Go To 9

No

- Repair the (K29) APP Signal 2 circuit for an open circuit or high resistance.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

9. ACCELERATOR PEDAL POSITION SENSOR
1. Turn the ignition off.
2. Connect the Powertrain Control Module (PCM) harness connector.
3. Turn the ignition on.
4. With the scan tool, read the Accelerator Pedal Position Sensor signal voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus 0.1 of a volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes

- Replace the Accelerator Pedal Position Sensor.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Go To 10

10. POWERTRAIN CONTROL MODULE (PCM)
1. 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).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM VERIFICATION TEST. PCM Verification Test.