STEP 1. Check the throttle actuator control motor relay.
STEP 2. Measure the power supply voltage at throttle actuator control motor relay harness side connector
STEP 3. Measure the power supply voltage at throttle actuator control motor relay harness side connector.
(1) Disconnect the throttle actuator control motor relay connector and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal coil power supply line and ground.- Voltage should be battery positive voltage.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is battery positive voltage (approximately 12 volts) present?
Go to Step 4. Repair or replace the connector(s), or check and repair the harness of short to ground and open circuit in coil power supply line between MFI relay connector and throttle actuator control motor relay connector. Then go to Step 11.
STEP 4. Measure the power supply voltage at ECM harness side connector.
(1) Disconnect the ECM connector and measure at the harness side.
(2) Short-circuit the terminal C/R of the ECM harness connector to the ground.
(3) Measure the voltage between terminal C/RL and ground.- Voltage should be battery positive voltage.
Is battery positive voltage (approximately 12 volts) present?
Go to Step 5. Repair or replace the connector(s), or check and repair the harness of short to ground and open circuit in C/RL line between throttle actuator control motor relay connector and ECM connector. Then go to Step 11.
STEP 5. Measure the power supply voltage at ECM harness side connector.
(1) Disconnect the ECM connector and measure at the harness side.
(2) Short-circuit the terminals C/R and C/RL of the ECM harness connector to the ground.
(3) Measure the voltage between terminal RSB and ground.- Voltage should be battery positive voltage.
Is battery positive voltage (approximately 12 volts) present?
Go to Step 8. Go to Step 6.
STEP 6. Check of short to ground and open circuit in RSB line between throttle actuator control motor relay connector and ECM connector.
STEP 7. Check of harness damage in coil power supply line between MFI relay connector and throttle actuator control motor relay connector.
STEP 8. Check of harness damage in battery power supply line between battery and throttle actuator control motor relay connector.
STEP 9. Check of harness damage in RSB line between throttle actuator control motor relay connector and ECM connector.
STEP 10. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
caution | To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III). |
(1) Connect scan tool (M.U.T-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) . (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 P0657 stored?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 11. 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 .
STEP 11. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
caution | To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III). |
(1) Connect scan tool (M.U.T-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) . (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 P0657 stored?
Retry the troubleshooting. The inspection is complete.