FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

DTC 14

DTC 14: Throttle Position Sensor System (Maladjusted Sensor)






CIRCUIT OPERATION
^ When the throttle valve shaft rotates from the idle position to the fully opened position, the resistance between the TPS output terminal (terminal 3) and ground terminal (terminal 1) will increase according to the rotation.
^ With the ignition switch in the "ON" position, voltage at pin 78 increases from around 0.7 volts at closed throttle to about 5 volts at wide open throttle.

DTC SET CONDITIONS
If TPS output voltage is 0.2 volts or lower or if it is 1.2 volts or higher when the engine is idling, the TPS adjustment is judged to be incorrect and diagnostic trouble code number "14" is set.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set:)
^ Malfunction of the throttle position sensor circuit
^ Damaged harness, connector
^ Malfunction of the PCM

DIAGNOSIS

Required Special Tool: MB991502: Scan Tool (MUT-II)





STEP 1. Using scan tool MB991502, read the A/T diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Read the A/T diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is A/T diagnostic trouble code number "11" or "12" set?
YES: Refer to code number 11: Throttle Position Sensor System (Short Circuit), code number 12: Throttle Position Sensor System (Open Circuit).
NO: Go to Step 2.





STEP 2. Using scan tool MB991502, check data list item 11: Throttle Position Sensor.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to data reading mode for item 11: Throttle Position Sensor.
^ With the throttle valve in idle position, voltage should be between 335 and 935 mV.
^ With the throttle valve in full-open position, voltage should be between 4,400 and 5,300 mV.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: This malfunction is intermittent.
NO: Go to Step 3.

STEP 3. Check the sensor output voltage at throttle position sensor connector B-3 by backprobing.





1. Do not disconnect connector B-03.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 1 and ground by backprobing.
^ With the throttle valve in idle position, voltage should be between 0.335 and 0.935 volts.
^ With the throttle valve in full-open position, voltage should be between 4.4 and 5.3 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 4.
NO: Go to Step 8.

STEP 4. Check the sensor output voltage at PCM connector C-116 by backprobing.





1. Do not disconnect connector C-116.





2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 78 and ground by backprobing.
^ With the throttle valve in idle position, voltage should be between 0.335 and 0.935 volts.
^ With the throttle valve in full-open position, voltage should be between 4.4 and 5.3 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 5.
NO: Go to Step 7.








STEP 5. Check connectors B-03 at throttle position sensor and C-116 at PCM for damage.
Q: Are the connectors in good condition?
YES: Go to Step 6.
NO: Repair or replace the defective connectors.





STEP 6. Using scan tool MB991502, check data list item 11: Throttle Position Sensor.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to data reading mode for item 11: Throttle Position Sensor.
^ With the throttle valve in idle position, voltage should be between 335 and 935 mV.
^ With the throttle valve in the full-open position, voltage should be between 4,400 and 5,300 mV.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: This malfunction is intermittent.
NO: Replace the PCM.








STEP 7. Check connectors B-03 at throttle position sensor and C-116 at PCM for damage.
Q: Are the connectors in good condition?
YES: Repair harness open circuit or damage between throttle position sensor connector B-03 terminal 1 and PCM connector C-116 terminal 78.
NO: Repair or replace the defective connectors.

STEP 8. Check the power supply voltage at throttle position sensor connector B-3 by backprobing.





1. Do not disconnect connector B-03.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 3 and ground by backprobing.
^ Voltage should be between 4.9 and 5.1 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 13.
NO: Go to Step 9.

STEP 9. Check the power supply voltage at PCM connector C-118 by backprobing.





1. Do not disconnect connector C-118.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 46 and ground by backprobing.
^ Voltage should be between 4.9 and 5.1 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 10.
NO: Go to Step 11.








STEP 10. Check connectors B-3 at throttle position sensor and C-118 at PCM for damage.
Q: Are the connectors in good condition?
YES: Repair harness open circuit or damage between throttle position sensor connector B-03 terminal 3 and PCM connector C-118 terminal 46.
NO: Repair or replace the defective connectors.








STEP 11. Check connectors B-3 at throttle position sensor and C-118 at PCM for damage.
Q: Are the connectors in good condition?
YES: Go to Step 12.
NO: Repair or replace the defective connectors.








STEP 12. Check the harness for short circuit to ground between throttle position sensor connector B-03 terminal 3 and PCM connector C-118 terminal 46.
Q: Is the harness wire in good condition?
YES: Go to Step 6.
NO: Repair it.

STEP 13. Check the ground voltage at throttle position sensor connector B-03 by backprobing.





1. Do not disconnect connector B-03.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 2 and ground by backprobing.
^ Voltage should be 0.5 volt or less.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 17.
NO: Go to Step 14.

STEP 14. Check the ground voltage at PCM connector C118 by backprobing.





1. Do not disconnect connector C-118.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 57 and ground by backprobing.
^ Voltage should be 0.5 volt or less.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 15.
NO: Go to Step 16.








STEP 15. Check connectors B-3 at throttle position sensor and C-118 at PCM for damage.
Q: Are the connectors in good condition?
YES: Repair harness open circuit or damage between throttle position sensor connector B-03 terminal 2 and PCM connector C-118 terminal 57.
NO: Repair or replace the defective connectors.





STEP 16. Check connector C-118 at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 6.
NO: Repair or replace it.





STEP 17. Check connector B-3 at throttle position sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 18.
NO: Repair or replace it.

STEP 18. Check the throttle position sensor.





1. Disconnect connector B-03 and measure at the sensor side.





2. Measure the resistance between terminal 2 and 3.
Standard value: 3.5 - 6.5 k Ohms





3. Measure the resistance between the throttle position sensor side connector terminals 1 and 2.
4. Move the throttle valve from idle position to full-open position.
^ Resistance should change smoothly in proportion to opening angle of the throttle valve.
Q: Is the resistance normal?
YES: Go to Step 19.
NO: Replace the throttle position sensor.





STEP 19. Check connectors C-116, C-118 at PCM for damage.
Q: Are the connectors in good condition?
YES: Go to Step 20.
NO: Repair or replace the defective connectors.








STEP 20. Check the harness for short circuit to ground or damage between throttle position sensor connector B43 terminal 1 and PCM connector C-116 terminal 78.
Q: Is the harness wire in good condition?
YES: Go to Step 21.
NO: Repair it.

STEP 21. Check the connector and the harness for short circuit to ground between the throttle position sensor connector and the auto-cruise control-ECU connector.
Q: Is the harness wire in good condition?
YES: Adjust the throttle position sensor.
NO: Repair it.