P0685 - ECM/PCM Power Relay Circuit Open

ECM/PCM power relay circuit open.

Code Overview

ECM/PCM power relay circuit open.

Common Causes

• Component failure
• Wiring/connectors issue
• System condition causing fault

Diagnostic Steps

1. Check for related codes and freeze-frame data
2. Inspect wiring/connectors for damage/corrosion
3. Verify sensor readings on a scan tool if available
4. Clear code and road test to confirm fix

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

Browse the closest code-family pages when the same fault pattern often shows up nearby.

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.