Q: car cranks but wont start. check engine light on. code p0685

asked by on October 04, 2016

Drove home from work, stopped on my way. car would crank but not start. my dash said "engine power reduced" i unhooked the battery and came back to the car an hour or so later and it started right up, I drove it about 3 miles and same thing, except this time it happened while i was driving. I called a tow truck driver and when he got there he jump started the car and it started right up on the first try. "Engine power reduced" warning went away but check engine light came on. I bought a code reader and it gave me p0685 "Ecn/pcm power control module relay/open". Car starts anytime i try to start it now, but i dont want to drive it anywhere and have to get it towed home again.

My car has 149000 miles.
My car has an automatic transmission.

Ignition Relay Replacement $89.03 - $216.75 Get a Quote

The code P0685 indicates a problem with Engine Control Ignition Relay Control Circuit. This may have a poor connection or need to be replaced. I would recommend having an expert from YourMechanic come to your home to diagnose and repair.

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