P0657

DTC P0657: Throttle Actuator Control Motor Relay Circuit Malfunction

CAUTION:
If DTC P0657 has been set, TCL related DTC U1120 is also set. After P0657 has been diagnosed, don't forget to erase DTC U1120.






















CIRCUIT OPERATION

- Battery positive voltage is applied to the throttle actuator control motor relay terminal (terminal No. 1).
- Battery positive voltage is applied to the throttle actuator control motor relay terminal (terminal No. 2) from the MFI relay (terminal No. 4).
- ECM [M/T] or PCM [A/T] (terminal No. 123) applies current to the throttle actuator control motor relay coil by turning ON the power transistor in the unit in order to turn the relay ON.
- When the throttle actuator control motor relay turns ON, battery positive voltage is supplied by the throttle actuator control motor relay (terminal No. 4) to the ECM [M/T] or the PCM [A/T] (terminal No. 122).

TECHNICAL DESCRIPTION

- When the ignition switch ON signal is input into the ECM [M/T] or the PCM [A/T], the ECM [M/T] or the PCM [A/T] turns ON the throttle actuator control motor relay.

DESCRIPTIONS OF MONITOR METHODS

Throttle actuator control motor relay circuit voltage is smaller than the specified value.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Not applicable

DTC SET CONDITIONS

Check Condition

- Battery positive voltage is higher than 8.3 volts.
Judgement Criterion

- The power line voltage of the electronic controlled throttle valve system should be 6.0 volts or less for 0.35 second.

OBD-II DRIVE CYCLE PATTERN

None.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- Throttle actuator control motor relay failed.
- Open or shorted throttle actuator control motor relay circuit, or connector damage.
- ECM failed.[ M/T]
- PCM failed.[ A/T]

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Check harness connector B-13X at throttle actuator control motor relay for damage.





Q. Is the harness connector in good condition?

YES Go to Step 2.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 14.

STEP 2. Check the throttle actuator control motor relay.

CAUTION:
Because it is not possible to distinguish the top and the bottom of the throttle actuator control motor relay, inspect it with the triangle mark printed on the relay facing upward.





(1)Remove the throttle actuator control motor relay.





(2)Check for continuity between the throttle actuator control motor relay terminal No. 2 and No. 3.

- There should be continuity (approximately 70 ohms).





(3)Use jumper wires to connect throttle actuator control motor relay terminal No. 2 to the positive battery terminal and terminal No. 3 to the negative battery terminal.
(4)Check the continuity between the throttle actuator control motor relay terminal No. 1 and No. 4 while connecting and disconnecting the jumper wire at the negative battery terminal.

- Should be less than 2 ohms. (Negative battery terminal connected.)
- Should be open loop. (Negative battery terminal disconnected.)
(5)Install the throttle actuator control motor relay.

Q. Is the measured resistance normal?

YES Go to Step 3.

NO Replace the throttle actuator control motor relay. Then go to Step 14.

STEP 3. Measure the power supply voltage at throttle actuator control motor relay harness side connector B-13X

CAUTION:
Because it is difficult to distinguish the top and bottom of the throttle actuator control motor relay connector at the wiring harness, inspect it by using triangle mark on the junction block as a reference.





(1)Disconnect the connector B-13X and measure at the harness side.





(2)Measure the voltage between terminal No. 1 and ground.

- Voltage should be battery positive voltage.

Q. Is battery positive voltage (approximately 12 volts) present?

YES Go to Step 4.

NO Check harness connector A-15 at intermediate connector for damage, and repair or replace as required. Harness Connector Inspection.
If intermediate connector A-15 is in good condition, repair it because of open circuit or short circuit to ground between battery and throttle actuator control motor relay connector B-13X (terminal No. 1). Then go to Step 14.

STEP 4. Measure the power supply voltage at throttle actuator control motor relay harness side connector B-13X.

CAUTION:
Because it is difficult to distinguish the top and bottom of the throttle actuator control motor relay connector at the wiring harness, inspect it by using triangle mark on the junction block as a reference.





(1)Disconnect the connector B-13X and measure at the harness side.
(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 2 and ground.

- Voltage should be battery positive voltage.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is battery positive voltage (approximately 12 volts) present?

YES Go to Step 6.

NO Go to Step 5.

STEP 5. Check harness connector B-16X at MFI relay for damage.





Q. Is the harness connector in good condition?

YES Repair harness wire between MFI relay connector B-16X (terminal No. 4) and throttle actuator control motor relay connector B-13X (terminal No. 2) because of open circuit or short circuit to ground. Then go to Step 14.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 14.

STEP 6. Measure the power supply voltage at ECM [M/T] or PCM [A/T] harness side connector B-22.





(1)Disconnect the connector B-22 and measure at the harness side.
(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 123 and ground.

- Voltage should be battery positive voltage.
(4)Turn the ignition switch to the "LOCK"(OFF) position.

Q. Is battery positive voltage (approximately 12 volts) present?

YES Go to Step 7.

NO Repair harness wire between throttle actuator control motor relay connector B-13X (terminal No. 3) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 123) because of open circuit or short circuit to ground. Then go to Step 14.

STEP 7. Measure the power supply voltage at ECM [M/T] or PCM [A/T] harness side connector B-22.





(1)Disconnect the connector B-22 and measure at the harness side.
(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 122 and ground.

- Voltage should be battery positive voltage.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is battery positive voltage (approximately 12 volts) present?

YES Go to Step 10.

NO Go to Step 8.

STEP 8. Check for open circuit and short circuit to ground between throttle actuator control motor relay connector B-13X (terminal No. 4) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 122).









Q. Is the harness wire in good condition?

YES Go to Step 9.

NO Repair it. Then go to Step 14.

STEP 9. Check for harness damage between MFI relay connector B-16X (terminal No. 4) and throttle actuator control motor relay connector B-13X (terminal No. 2).









Q. Is the harness wire in good condition?

YES Repair harness wire between throttle actuator control motor relay connector B-13X (terminal No. 3) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 123) because of harness damage. Then go to Step 14.

NO Repair it. Then go to Step 14.

STEP 10. Check harness connector B-22 at ECM [M/T] or PCM [A/T] for damage.





Q. Is the harness connector in good condition?

YES Go to Step 11.

NO Repair or replace it. Harness Connector Inspection.
Then go to Step 14.

STEP 11. Check for harness damage between battery and throttle actuator control motor relay connector B-13X (terminal No. 1).





Q. Is the harness wire in good condition?

YES Go to Step 12.

NO Repair it. Then go to Step 14.

STEP 12. Check for harness damage between throttle actuator control motor relay connector B-13X (terminal No. 4) and ECM [M/T] or PCM [A/T] connector B-22 (terminal No. 122).









Q. Is the harness wire in good condition?

YES Go to Step 13.

NO Repair it. Then go to Step 14.

STEP 13. Using scan tool MB991958, read the diagnostic trouble code
(DTC).





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)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.

Q. Is DTC P0657 set?

YES Replace the ECM or the PCM. When the ECM or the PCM is replaced, register the encrypted code. Immobilizer System.
Then go to Step 14.

NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

STEP 14. Using scan tool MB991958, read the diagnostic trouble code
(DTC).





(1)Connect scan tool MB991958 to the data link connector.
(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.

Q. Is DTC P0657 set?

YES Retry the troubleshooting.

NO The inspection is complete.