DTC P0685
Precautions: General safety (00)
DTC Detecting Condition and Trouble Area
| DTC detecting condition | Trouble area |
|---|---|
|
P0685: ECM / PCM Power Relay Control Circuit / Open Any of the following conditions is met.
•Measured voltage of main relay drive circuit is higher than specified value even when command signal of main relay is ON. (1 D/C detection logic)•Measured voltage of main relay drive circuit is lower than specified value even when command signal of main relay is OFF. |
•Main relay and/or its circuit
•ECM |
Circuit Diagram
| [A]: | ECM connector (View: [a]) | B2: | ECM power supply circuit | 1. | ECM |
| A1: | Main relay power supply circuit (coil side) | B3: | ECM power supply circuit | 2. | Main relay |
| A2: | Main relay power supply circuit (switch side) | C1: | ECM ground circuit | 3. | “FI” fuse (30 A) |
| A3: | Main relay drive circuit | C2: | ECM ground circuit | ||
| B1: | ECM power supply circuit | C3: | ECM ground circuit |
DTC Troubleshooting
| Step | Action | Yes | No |
|---|---|---|---|
| 1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
|
|
| 2 |
Main relay power supply circuit (coil side) and main relay drive circuit check
1)Check “A1” and “A3” circuits according to Step 1 – 2 of Main Relay Operation Check:D16AA.
Is check result OK?
|
Go to Step 3.
|
Repair or replace defective wire harness.
|
| 3 |
Main relay check
1)Check main relay for resistance.
Is check result OK?
|
Replace ECM and recheck DTC.
|
Replace main relay.
|