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P2127






P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW

Special Tools:










For a complete wiring diagram Refer to the Wiring Information.

- When Monitored:
With the ignition on and no other APPS No.2 DTCs present.

- Set Condition:
When the APP Sensor No.2 voltage is too low. Engine will only idle if the Brake pedal is Pressed or has failed. 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. Pre-Diagnostic Troubleshooting Procedure.

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

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

NOTE: If you are viewing data recorder information or Freeze Frame data the APP Sensor No. 2 is pulled low by the PCM as part of its system testing. This test happens every 320 milliseconds and may not show up on the scan tool but may show up on a data recorder or lab scope. It is acceptable to see the voltage close to zero with a normal sensor when using a data recorder/lab scope.

2. With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Go To 11

2. (F856) 5-VOLT SUPPLY CIRCUIT




1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (F856) 5-volt Supply circuit in the APP Sensor harness connector.

Is the voltage between 4.5 and 5.2 volts?

Yes

- Go To 3

No

- Go To 8

3. (K29) APP SENSOR NO.2 SIGNAL CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the PCM harness connectors.

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 (8815A) to perform diagnosis.

3. Measure the resistance of the (K29) APP Sensor No.2 Signal circuit from the APP Sensor harness connector to the appropriate terminal of special tool #.

Is the resistance below 5.0 ohms?

Yes

- Go To 4

No

- Repair the open in the (K29) APP Sensor No.2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. (K29) APP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (K29) APP Sensor No.2 Signal circuit in the APP Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (K29) APP Sensor No.2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. (K29) APP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO THE (K400) APP SENSOR NO.2 RETURN CIRCUIT




1. Measure the resistance between the (K29) APP Sensor No.2 Signal circuit and the (K400) APP Sensor No.2 Return circuit in the APP Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short between the (K400) APP Sensor No.2 Return circuit and the (K29) APP Sensor No.2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. (K29) APP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO THE (K167) APP SENSOR NO.1 RETURN CIRCUIT




1. Measure the resistance between the (K29) APP Sensor No.2 Signal circuit and the (K167) APP Sensor No.1 Return circuit in the APP Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short between the (K167) APP Sensor No.1 Return circuit and the (K29) APP Sensor No.2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 7

7. ACCELERATOR PEDAL POSITION SENSOR




1. Connect the PCM harness connectors.
2. Ignition on, engine not running.
3. Connect a jumper wire between the (F856) 5-volt Supply circuit and the (K29) APP Sensor No.2 Signal circuit in the Sensor harness connector.
4. With a scan tool, monitor the APP Sensor No.2 voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the jumper wire installed.

Does the scan tool display the voltage as described above?

Yes

- Verify that there is good pin to terminal contact in the APPS and the Powertrain Control Module connectors. Replace the APP Sensor Assembly if no problems were found with the connectors. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 10
- NOTE: Remove the jumper wire before continuing.


8. (F856) 5-VOLT SUPPLY CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the C1 PCM harness connector.

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 (8815A) to perform diagnosis.

3. Measure the resistance of the (F856) 5-volt Supply circuit from the Sensor harness connector to the appropriate terminal of special tool #.

Is the resistance below 5.0 ohms?

Yes

- Go To 9

No

- Repair the open in the (F856) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

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




1. Measure the resistance between ground and the (F856) 5-volt Supply circuit in the APP Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (F856) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain 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. Verify that there is good pin to terminal contact in the APPS and the Powertrain Control Module connectors.
4. Search for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

11. APP SENSOR SWEEP
1. Ignition on, engine not running.
2. With a scan tool, monitor the APP Sensor 2 voltage.
3. Slowly press the Accelerator pedal down.

Does voltage start at approximately 0.22 of a volt and go above 2.31 volts with a smooth transition?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test

No

- Replace the APP Sensor Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

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