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P0622

DTC P0622: Generator FR Terminal Circuit Malfunction

Generator Circuit Part 1:




Generator Circuit Part 2:






CIRCUIT OPERATION
- The ECM (terminal 41) or PCM (terminal 54) apply a battery positive voltage into the generator FR terminal 4 via resistance inside the unit.

TECHNICAL DESCRIPTION
- When the generator field coils are controlled, the generator FR terminal inputs signal to the ECM or PCM
.
- The ECM or PCM
detects the generator output with the input signal, and controls the idle air control motor according to the generator output.

DTC SET CONDITIONS

Check Conditions
- Engine speed is higher than 50 r/min.

Judgement Criteria
- Input voltage from the generator FR terminal has continued to be approximately battery positive voltage for 20 seconds.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set area:)
- Open circuit in generator FR terminal circuit.
- ECM failed.
- PCM failed.


DIAGNOSIS

STEP 1. Check the voltage at generator intermediate connector B-13 by backprobing.

1. Do not disconnect the connector B-13.
2. Start the engine and run at idle.




3. Measure the voltage between terminal 3 and ground by backprobing.
a. Engine: warming up
b. Radiator fan: stopped
c. Headlight switch: OFF to ON
d. Rear defogger switch: OFF to ON
e. Stoplight switch: OFF to ON
- Voltage should be drops.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the voltage normal?

YES: Go to Step 2.

NO: Go to Step 4.




STEP 2. Check connector B-13 at generator intermediate connector for damage.

Q: Is the connector in good condition?

YES: Go to Step 3.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

STEP 3. Check the trouble symptoms.

1. Carry out a test drive with the drive cycle pattern. Refer to Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).

Q: Is the DTC P1500 is output?

YES: Replace the ECM or PCM. Then go to Step 11.

NO: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.




STEP 4. Check connector B-13 at generator intermediate connector for damage.

Q: Is the connector in good condition?

YES: Go to Step 5.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.




STEP 5. Check connector B-45 at generator connector for damage.

Q: Is the connector in good condition?

YES: Go to Step 6.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

STEP 6. Check the voltage at generator harness side connector B-45.

1. Disconnect the connector B-45 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal 4 and ground.
- Voltage should be battery positive voltage.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the voltage normal?

YES: Go to Step 9.

NO: Go to Step 7.




STEP 7. Check connector C-53 at ECM or connector C-54 at PCM
for damage.

Q: Is the connector in good condition?

YES: Go to Step 8.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.







STEP 8. Check for open circuit and short circuit to ground between generator connector B-45 (terminal 4) and ECM connector C-53 (terminal 41) or PCM connector C-54 (terminal 54)
.

Q: Is the harness wire in good condition?

YES: Replace the ECM or PCM. Then go to Step 11.

NO: Repair it. Then go to Step 11.




STEP 9. Check connector C-53 at ECM or connector C-54 at PCM
for damage.

Q: Is the connector in good condition?

YES: Go to Step 10.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.







STEP 10. Check for harness damage between generator connector B-45 (terminal 4) and ECM connector C-53 (terminal 41) or PCM connector C-54 (terminal 54)
.

Q: Is the harness wire in good condition?

YES: Replace the generator. Then go to Step 11.

NO: Repair it. Then go to Step 11.

STEP 11. Using scan tool MB991502, read the diagnostic trouble code (DTC).






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 DTC.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC P0622 is output?

YES: Retry the troubleshooting.

NO: The inspection is complete.