B2521

B2521 ECU CIRCUIT

DTC Logic


DTC DETECTION LOGIC

[B2521] ECU circuit






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. Testing and Inspection.
Is DTC "B2521" detected?
YES- .
NO- Intermittent Incident.


Diagnosis Procedure


1. CHECK EACH SENSOR POWER SUPPLY

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





Is the measurement value within the standard value?
YES- Replace AFS control unit. 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 the ignition switch OFF.
2.Disconnect AFS control unit connector.
3.Check continuity between the AFS control unit harness connector and the ground.





Does continuity exist?
YES- Repair the harnesses or connectors.
NO- Replace AFS control unit. Removal And Installation

4. CHECK EACH SENSOR POWER SUPPLY SHORT CIRCUIT

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





Is the measurement value normal?
YES- Replace AFS control unit. Removal And Installation
NO- Repair the harnesses or connectors.

5. CHECK EACH SENSOR SIGNAL SHORT CIRCUIT

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





Does continuity exist?
YES- Repair the harnesses or connectors.
NO- Replace AFS control unit. Removal And Installation

6. CHECK EACH SENSOR SIGNAL SHORT CIRCUIT

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





Is the measurement value normal?
YES- Replace AFS control unit. Removal And Installation
NO- Repair the harnesses or connectors.