OBD-II Generic Error Code P0690: How to Fix It

Q: Can I drive with error code P0690?

It is not recommended. The error can cause erratic engine behavior, stalling, or no-start conditions. Have it diagnosed and fixed as soon as possible.

Q: What causes P0690?

Common causes include a bad main relay, blown fuse, faulty battery or alternator, corroded wiring, or a failing ECM/PCM.

Q: Will clearing the code fix P0690?

Clearing the code with an OBD2 scanner may turn off the check engine light, but if the underlying issue isn't fixed, the code will return.

Q: How much does it cost to fix P0690?

Cost varies: replacing a relay or fuse is under $20; a new battery $100-200; alternator $300-600; ECM replacement can be $500-1000+ including programming.

Q: What tools do I need to diagnose P0690?

You'll need a multimeter, OBD2 scanner, and basic hand tools. A wiring diagram for your vehicle is also helpful.

Abstract

Error code P0690 indicates a high voltage condition in the ECM/PCM power relay sense circuit. This typically means the powertrain control module has detected an abnormal voltage from the main relay or wiring issue. It can cause drivability problems and should be addressed promptly.