The Lemon IndexThe relay that powers the engine computer has a circuit fault.
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
Failed main relay. Then: wiring fault.
Owners named P0685 in 11 complaints to the U.S. government, most often on the Ford Escape.
Cars owners report it on
Complaints that name P0685, by model. Raw counts, not a failure rate: popular models get more complaints.
Years owners report it on most: 2007 Honda Accord
The details
What P0685 means
The relay that powers the engine computer has a circuit fault.
Can I drive with P0685?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
55% of the owner complaints that name P0685 also say the car brakes or ABS act up. A complaint can describe more than one problem, so this doesn't prove the code caused it.
Common causes of P0685
- Failed main relay
- Wiring fault
A shop should confirm the cause with a scan and tests before replacing parts.
What owners describe
- Brakes or ABS act up: 55% of complaints
- Loses power or goes into limp mode: 45% of complaints
- Warning lights and electrical faults: 36% of complaints
- Stalls or shuts off: 36% of complaints
Share of complaints naming the code whose text also mentions each problem.
Model years that report P0685 most
2007 Honda Accord (2).
Related codes
P068A P069E P0657 P06B8 P0651 P0638 P06DA P06DD
Quick answers
What does P0685 mean?
ECM/PCM Power Relay Control Circuit/Open. The relay that powers the engine computer has a circuit fault.
Can I drive with P0685?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
What causes P0685?
Failed main relay; Wiring fault.
Counts: NHTSA owner complaints whose text names P0685. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.