P0622
Generator Circuit:
Connectors:
Connectors:
DTC P0622: Generator FR Terminal Circuit
CIRCUIT OPERATION
- The ECM (terminal No. 41)
TECHNICAL DESCRIPTION
- When the generator field coils are controlled, the generator FR terminal inputs signal to the ECM
- The ECM
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 or shorted generator FR terminal circuit, or harness damage, or connector damage.
- ECM failed.
- PCM failed.
DIAGNOSIS
STEP 1. Measure 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 No. 3 and go 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 Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0622 set?
YES: Replace the ECM or PCM. Then go to Step 11.
NO: It can be assumed that this malfunction is intermittent. Refer to INTRODUCTION, How to Use Troubleshooting/Inspection Service Points - How to - Cope with Intermittent Malfunctions.
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-115 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. Measure the voltage at generator harness side connector B-115.
1. Disconnect the connector B-115 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 4 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 9.
NO: Go to Step 7.
STEP 7. Check connector C-113 at ECM
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-115 (terminal No. 4) and ECM connector C-113 (terminal No. 41)
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-113 at ECM
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-115 (terminal No. 4) and ECM connector C-113 (terminal No. 41)
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 DTC P0622 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.