STEP 1. Using scan tool MB991958, check data list item 13: Throttle Position Sensor (main).
caution | To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. |
(1) Connect scan tool MB991958 to the data link connector.
(2) Detach the intake air hose at the throttle body.
(3) Disconnect the connector of the electronic-controlled throttle valve.
(4) Use test harness special tool (MB991658) to connect only terminals No. 3, No. 4, No. 5, and No. 6.
(5) Turn the ignition switch to the "ON" position.
(6) Set scan tool MB991958 to the data reading mode for item 13, Throttle Position Sensor (main).- Output voltage should be between 300 and 700 millivolts when the throttle valve is fully closed with your finger.
- Output voltage should be 4,000 millivolts or more when the throttle valve is fully open with your finger.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
Is the sensor operating properly?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions . Go to Step 2.
STEP 2. Check harness connector B-12 at electronic-controlled throttle valve for damage.
STEP 3. Measure the sensor supply voltage at electronic-controlled throttle valve harness side connector B-12.
(1) Disconnect the connector B-12 and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 5 and ground.- Voltage should be between 4.9 and 5.1 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 4.9 and 5.1 volts?
Go to Step 6. Go to Step 4.
STEP 4. Check harness connector B-26 at ECM for damage.
STEP 5. Check for open circuit and short circuit to ground between electronic-controlled throttle valve connector B-12 (terminal No. 5) and ECM connector B-26 (terminal No. 12).
STEP 6. Check the continuity at electronic-controlled throttle valve harness side connector B-12.
STEP 7. Check harness connector B-26 at ECM for damage.
STEP 8. Check for open circuit and harness damage between electronic-controlled throttle valve connector B-12 (terminal No. 3) and ECM connector B-26 (terminal No. 13).
STEP 9. Using scan tool MB991958, check data list item 13: Throttle Position Sensor (main).
(1) Detach the intake air hose at the throttle body.
(2) Disconnect the connector of the electronic-controlled throttle valve.
(3) Use test harness special tool (MB991658) to connect only terminals No. 3, No. 4, No. 5, and No. 6.
(4) Turn the ignition switch to the "ON" position.
(5) Set scan tool MB991958 to the data reading mode for item 13, Throttle Position Sensor (main).- Output voltage should be between 300 and 700 millivolts when the throttle valve is fully closed with your finger.
- Output voltage should be 4,000 millivolts or more when the throttle valve is fully open with your finger.
(6) Turn the ignition switch to the "LOCK" (OFF) position.
Is the sensor operating properly?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions . Replace the ECM (Refer to, Removal and Installation ). Then go to Step 14.
STEP 10. Check harness connector B-26 at ECM for damage.
STEP 11. Check for harness damage between electronic-controlled throttle valve connector B-12 (terminal No. 5) and ECM connector B-26 (terminal No. 12).
STEP 12. Check for open circuit and harness damage between electronic-controlled throttle valve connector B-12 (terminal No. 4) and ECM connector B-26 (terminal No. 10).
STEP 13. Replace the throttle body assembly.
(1) Replace the throttle body assembly.
(2) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC P0123 set?
Replace the ECM (Refer to, Removal and Installation ). Then go to Step 14. The inspection is complete.
STEP 14. Using scan tool MB991958, read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the DTC has been deleted, read the DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC P0123 set?
Retry the troubleshooting. The inspection is complete.