Throttle Position Sensor: Testing and Inspection
CHECKING THE THROTTLE POSITION SENSORS
For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.
1. THROTTLE FOLLOWER TEST
NOTE: Diagnose and repair any throttle position sensor or electronic throttle control motor DTCs before continuing.
1. Turn the ignition on.
2. With a scan tool, perform the Throttle Follower Test and monitor the TP Sensor 1 or 2 voltage as applicable.
3. Slowly press the throttle pedal down.
4. The voltage for sensor 1 should start at approximately 0.3 of a volt and increase to above 4.7 volts.
5. The voltage for sensor 2 should start at approximately 4.7 volts and decrease to approximately 0.3 of a volt.
Is the voltage within the range of the listed specification for the appropriate sensor?
Yes
- Test complete.
No
- Go to 2
2. WIRING AND CONNECTOR INSPECTION
NOTE: Perform the following procedures for each sensor that was not within the specified range as described in the previous step.
1. Turn the ignition off.
2. Verify that the harness connector is properly connected to the throttle body.
3. Disconnect the throttle body connector.
4. Inspect the wiring and terminals for any condition that would result in a poor connection.
5. Look for any chafed, pierced, pinched, or partially broken wires.
6. Look for broken, bent, pushed out or corroded terminals.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test.PCM Verification Test
No
- Go to 3
3. SENSOR VOLTAGE
1. Connect a jumper wire between the signal circuit and the sensor ground circuit in the throttle body harness connector.
2. Turn the ignition on.
3. With a scan tool, read the sensor voltage.
NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.
Does the scan tool display the voltage as described above?
Yes
- Go to 4
No
- Go to 5
4. THROTTLE POSITION SENSOR
1. Turn the ignition off.
2. Connect a jumper wire between the signal circuit and the 5 volt supply circuit in the throttle body harness connector.
3. Turn the ignition on.
4. With a scan tool, read the sensor voltage.
NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the jumper wire in place.
Does the scan tool display the voltage as described above?
Yes
- Replace the applicable throttle body.
- Perform the PCM Verification Test.PCM Verification Test
No
- Go to 5
5. SIGNAL CIRCUIT SHORTED TO THE 5 VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module harness connector.
3. Measure the resistance between the signal circuit and the 5 volt supply in the throttle body harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the signal circuit for a short to the 5 volt supply circuit.
- Perform the PCM Verification Test.PCM Verification Test
No
- Go to 6
6. SIGNAL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the signal circuit in the sensor harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the signal circuit for a short to ground.
- Perform the PCM Verification Test.PCM Verification Test
No
- Go to 7
7. SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
1. Measure the resistance between the signal circuit and the sensor ground circuit in the sensor harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the signal circuit for a short to the sensor ground circuit.
- Perform the PCM Verification Test.PCM Verification Test
No
- Go to 8
8. 5 VOLT SUPPLY CIRCUIT HIGH RESISTANCE
1. Turn the ignition off.
2. Connect the throttle body harness connector.
3. Using a voltmeter, perform a voltage drop test by backprobing the 5 volt supply circuit at the throttle body harness connector and at the PCM harness connector. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
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 fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
4. Start the engine.
Is the voltage below 0.5 volts?
Yes
- Go to 9
No
- Repair the 5 volt supply circuit for high resistance.
- Perform the PCM Verification Test.PCM Verification Test
9. SIGNAL CIRCUIT HIGH RESISTANCE
1. Turn the ignition off.
2. Connect the throttle position sensor harness connector.
3. Using a voltmeter, perform a voltage drop test by backprobing the signal circuit at the throttle body harness connector and at the PCM connector. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
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 fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
4. Start the engine.
Is the voltage below 0.5 volts?
Yes
- Go to 10
No
- Repair the signal circuit for high resistance.
- Perform the PCM Verification Test.PCM Verification Test
10. SENSOR GROUND CIRCUIT HIGH RESISTANCE
1. Turn the ignition off.
2. Using a voltmeter, perform a voltage drop test by backprobing the sensor ground circuit at the throttle body harness connector and at the PCM connector. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
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 fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
3. Start the engine.
Is the voltage below 0.5 volts?
Yes
- Go to 11
No
- Repair the sensor ground circuit for high resistance.
- Perform the PCM Verification Test.PCM Verification Test
11. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the throttle body and the PCM. Refer to the system schematic.
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 a DTC to set during the wiggle test.
6. Search for 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 the PCM.
- Perform the PCM Verification Test.PCM Verification Test