Engine Code
P0122-THROTTLE POSITION SENSOR #1 LOWP0122-Throttle Position Sensor #1 Low:
WHEN MONITORED
With the ignition on. Battery voltage greater than 10 volts.
SET CONDITION
Throttle Position Sensor voltage at the PCM is less than 0.0978 of a volt. One Trip Fault.
POSSIBLE CAUSES
- (F855) 5 volt supply circuit shorted to ground
- (F855) 5 volt supply circuit open
- TP sensor internal failure
- (K22) TP signal circuit shorted to ground
- (K22) TP signal circuit shorted to (K900) sensor ground circuit
- Throttle position sensor
- PCM
Diagnostic Test
1. THROTTLE POSITION SENSOR BELOW 0.2 OF A VOLT
Ignition on, engine not running.
With a scan tool, read the Throttle Position Sensor voltage.
Q: Is the voltage below 0.2 of a volt?
YES: Go To 2
NO: Go To 10
2. (F855) 5 VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the TP Sensor harness connector. Ignition on, engine not running.
Measure the voltage of the (F855) 5 volt Supply circuit in the TP Sensor harness connector.
Q: Is the voltage between 4.5 to 5.2 volts?
YES: Go To 3
NO: Go To 7
3. TP SENSOR INTERNAL FAILURE
Turn the ignition off.
Disconnect the TP Sensor harness connector.
With the scan tool, monitor the TP Sensor voltage.
Ignition on, engine not running.
Q: Is the voltage above 4.5 volts?
YES: Replace the Throttle Position Sensor. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. (K22) TP SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the TP harness connector.
Disconnect the PCM harness connector.
Measure the resistance between ground and the (K22) TP Signal circuit at the TP Sensor harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (K22) TP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5
5. (K22) TP SENSOR SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
Turn the ignition off.
Disconnect the TP Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance between the (K22) TP Signal circuit and the (K900) Sensor ground circuit in the TP harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to (K900) Sensor ground in the (K22) TP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 6
6. PCM (K22) TP SIGNAL CIRCUIT
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. (F855) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the TP Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance between ground and the (F855) 5 volt Supply circuit in the TP Sensor harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (F855) 5 volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 8
8. (F855) 5 VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.
Disconnect the TP Sensor harness connector.
Disconnect the 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 miller special tool #8815 to perform diagnosis.
Measure the resistance of the (F855) 5 volt Supply circuit from the TP Sensor harness connector to the appropriate terminal of special tool #8815.
Q: Is the resistance below 5.0 ohms?
YES: Go To 9
NO: Repair the open in the (F855) 5 volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
9. PCM (F855) 5 VOLT SUPPLY CIRCUIT
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
10. THROTTLE POSITION SENSOR SWEEP
Ignition on, engine not running.
With the scan tool, monitor the Throttle Position Sensor voltage.
Slowly open the throttle from the idle position to the wide open throttle position.
Q: Does voltage start at approximately 0.7 of a volt and go above 3.5 volts with a smooth transition?
YES: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace the Throttle Position Sensor. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test