Operation CHARM: Car repair manuals for everyone.

P0122






P0122 - APPS SIGNAL 1 CIRCUIT LOW





When Monitored and Set Condition

- When Monitored: With the ignition on and no other Accelerator Pedal Position (APP) Sensor 1 DTCs present.
- Set Condition: When the APP Sensor Signal 1 voltage is too low. Engine will only idle if the brake pedal is pressed or has failed. Acceleration rate and engine output are limited.







Diagnostic Test

1. PRE-DIAGNOSTIC CHECK OUT





NOTE: Always perform diagnostics with a fully charged battery.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

NOTE: Check for applicable TSBs related to the problem.

Turn the ignition on.

With the DRB III(R), read PCM DTCs.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.

Perform this procedure prior to symptom diagnosis.

Continue

- Go To 2

2. CHECK THE APP SENSOR VOLTAGE





Turn the ignition on.

With the DRB III(R), read the APP 1 voltage.

Is the voltage below 0.3 volt?

Yes

- Go To 3

No

- Go To 10

3. APP SENSOR 5-volt SUPPLY CIRCUIT





Turn the ignition off.

Disconnect the APP Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage of the APP Sensor 5-volt Supply circuit at the APP Sensor harness connector.

Is the voltage between 4.7 and 5.2 volts?

Yes

- Go To 4

No

- Go To 8

4. APP SENSOR





With the ignition on.

Connect a jumper wire between the APP Sensor 5-volt Supply circuit and the APP Sensor Signal 1 circuit in the APP Sensor harness connector.

With the DRB III(R), read the APP 1 voltage.

NOTE: Remove the jumper wire after this step has been completed.

Is the voltage above 4.7 volts?

Yes

- Replace the Accelerator Pedal Position Sensor.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

No

- Go To 5

5. APP SENSOR SIGNAL 1 CIRCUIT SHORT TO GROUND





Turn the ignition off.

Disconnect the PCM C4 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between ground and the APP Sensor Signal 1 circuit.

Is the resistance above 100 kohms?

Yes

- Go To 6

No

- Repair the APP Sensor Signal 1 circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

6. APP SENSOR SIGNAL 1 CIRCUIT SHORT TO SENSOR GROUND CIRCUIT(S)





With the ignition off.

Measure the resistance between the Sensor Ground circuits and the APP Sensor Signal 1 circuit.

Is the resistance above 100 kohms?

Yes

- Go To 7

No

- Repair the APP Sensor Signal 1 circuit for a short to the Sensor Ground circuit(s).
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

7. APP SENSOR SIGNAL CIRCUIT OPEN





With the ignition off.

Measure the resistance of the APP Sensor Signal 1 circuit from the APP Sensor harness connector to the PCM C4 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 9

No

- Repair the APP Sensor Signal circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

8. APP SENSOR 5-volt SUPPLY CIRCUIT OPEN





With the ignition on.

Measure the resistance of the APP Sensor 5-volt Supply circuit from the APP Sensor harness connector to the PCM C4 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 9

No

- Repair the APP Sensor 5-volt Supply circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

9. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

If there are no possible causes remaining, view repair.

Repair

- Replace and program the Powertrain Control Module.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

10. CHECK THE APP SENSOR SWEEP





With the ignition on.

With the DRB III(R), monitor the APP 1 voltage.

Slowly open the throttle from the idle position to the wide open throttle position.

Does voltage start at approximately 0.3 volt and go above 4.5 volts with a smooth transition?

Yes

- Go To 11

No

- Replace the Accelerator Pedal Position Sensor.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

11. INTERMITTENT WIRING AND CONNECTORS

The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

NOTE: Check for any Technical Service Bulletins that may apply.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

No

- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.