B2521

B2521 ECU CIRCUIT

DTC Logic


DTC DETECTION LOGIC







DTC CONFIRMATION PROCEDURE


1. DTC ERASE

Erase the DTC memory of AFS with CONSULT.
- GO TO 2.

2. DTC CONFIRMATION PROCEDURE

1.Turn ignition ON.
2.Select the self-diagnosis with CONSULT.
3.Check the self-diagnosis result. Refer to "DTC Index" Testing and Inspection.
Is DTC "B2521" detected?
YES- Refer to "Diagnosis Procedure" .
NO- Refer to "Intermittent Incident" Intermittent Incident.


Diagnosis Procedure


1. CHECK EACH SENSOR POWER SUPPLY

1.Turn ignition switch ON.
2.Check voltage between AFS control unit harness connector and ground.





Is the measurement value within the standard value?
YES- GO TO 2.
Less than the standard value -GO TO 3.
Higher than the standard value-GO TO 4.

2. CHECK EACH SENSOR SIGNAL

Check voltage between AFS control unit harness connector and ground.





Is the measurement value within the standard value?
YES- Replace AFS control unit. Refer to "Removal and Installation" Removal and Installation
Less than the standard value -GO TO 5.
Higher than the standard value-GO TO 6.

3. CHECK EACH SENSOR POWER SUPPLY SHORT CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect AFS control unit connector.
3.Check continuity between AFS control unit harness connector and ground.





Is the inspection result normal?
YES- Replace AFS control unit. Refer to "Removal and Installation" Removal and Installation
NO- Repair or replace harness.

4. CHECK EACH SENSOR POWER SUPPLY SHORT CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect AFS control unit connector.
3.Check voltage between AFS control unit harness connector and ground.





Is the inspection result normal?
YES- Replace AFS control unit. Refer to "Removal and Installation" Removal and Installation
NO- Repair or replace harness.

5. CHECK EACH SENSOR SIGNAL SHORT CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect AFS control unit connector.
3.Check continuity between AFS control unit harness connector and ground.





Is the inspection result normal?
YES- Replace AFS control unit. Refer to "Removal and Installation" Removal and Installation
NO- Repair or replace harness.

6. CHECK EACH SENSOR SIGNAL SHORT CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect AFS control unit connector.
3.Turn ignition switch ON.
4.Check voltage between AFS control unit harness connector and ground.





Is the inspection result normal?
YES- Replace AFS control unit. Refer to "Removal and Installation" Removal and Installation
NO- Repair or replace harness.