OBD2 code P0685: Engine computer - Internal error
Internal engine computer error.
Detected Root Component
Powertrain Component
Observed Symptoms
- Engine light on (MIL/Check Engine)
- Unable to start
- Dashboard errors
Possible Causes
- Faulty engine computer (ECU)
- Discharged or defective battery
- Alternator not charging
- Damaged wiring
Tools Required
Interactive Diagnostic
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Parts likely to be the cause (Moteur (général))
Moteur (général)
Photo d'illustration : Moteur (général)
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Frequently asked questions about code P0685
What does code P0685 mean? ▾
OBD2 code P0685: Engine computer - Internal error. Internal engine computer error.
What are the symptoms of code P0685? ▾
Code P0685 may cause: Engine light on (MIL/Check Engine), Unable to start, Dashboard errors. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code P0685? ▾
The most common causes of code P0685 are: Faulty engine computer (ECU), Discharged or defective battery, Alternator not charging, Damaged wiring. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code P0685? ▾
Yes, code P0685 is critical (Critical). Avoid driving and consult a professional promptly to prevent major damage.
How do I fix code P0685? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Faulty engine computer (ECU), Discharged or defective battery, Alternator not charging, Damaged wiring. Difficulty: Medium · Estimated time: 30-60min.