DTC P0687 ECM Power Relay Control Circuit High (4JJ3 without DPD)

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Diagnostic system check-engine controls".

2. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Inspection for short to power supply in ECM main relay power supply circuit.

No

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 without DPD) intermittent conditions of engine".

3. Inspection for short to power supply in ECM main relay power supply circuit

1) Turn OFF the ignition switch for 1 minute or more.

2) Remove the ECM main relay.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is DTC P0685 set?

Yes

=>Go to Inspection for short to power supply in ECM main relay control circuit.

No

Repair the short to the battery power supply in the battery power supply circuit between the ECM (pins 2, 3, 4, 5, and 6 of C9) and the ECM main relay (pin 2 of Fuse and Relay Box (Engine Compartment) ECM MAIN).

=>Go to Repair verification.

4. Inspection for short to power supply in ECM main relay control circuit

1) Turn OFF the ignition switch for 1 minute or more.

2) Replace the ECM main relay with a known good relay.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

Repair the short to the battery power supply in the control circuit between the ECM (pins 1 and 2 of C8) and the ECM main relay (pin 3 of Fuse and Relay Box (Engine Compartment) ECM MAIN).

=>Go to Repair verification.

No

Replace the ECM main relay.

=>Go to Repair verification.

5. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool.