Check engine light on and off, radio goes off for a few seconds and reboots

Honda accord( 2005), Engine lights off and on, Radio goes off a few seconds and then reboots by itself , ABS lights off and on, car still runs, power seems to be down slightly when engine lights comes on , stalled twice, but restarted right away. Relay switch replaced, PCM replaced( Diagnosis suggested) , problem continues.
What should I check next ?? please advise.

What code is being set when the check-engine light comes on? Many auto parts stores will read the code for free.

Has anyone tested the battery and alternator and made sure that all battery and ground connections are tight and not corroded?

hi just got code…#po685 thankyou


Faulty Engine Control Module (ECM) power relay

  • ECM power relay harness is open or shorted
  • ECM power relay circuit poor electrical connection
  • Faulty (ECM)

I’d think you have a wire shorted somewhere…probably under the dash. Has anyone been working under the dash lately. Replacing the Radio maybe.

Or you could check the battery connections for corrosion.


I would start by inspecting all the wiring around your battery and and cleaning any corrosion from your battery terminals and other connection points for hot and ground wires, and making sure you have tight, solid connections there. Also check the aforementioned relay, make sure it is well seated in its connector, and that all the wiring there and the relay socket is in good shape.

In the under hood fuse and relay box, look for the fuse marked radio. This fuse provides keep alive power to the radio and the PCM (ECM) for their memories. It may have a crack in the element or maybe a corroded terminal.

My guess is a burned or corroded connection at a connector involved with that relay.

When you say the relay switch was replaced, do you mean the relay (a type of switch) was replaced? If so, even more would I say this is a wiring harness or connector problem. An experience auto-electric tech could probably find out what is wrong without too much trouble, just by following the wiring diagram and tracing out some test points at a time when this was happening.

Are you able to reproduce this effect at will?

"What should I check next ??"
What have you checked so far?

To me it sounds like a possible bad battery cable connection.

My guess would be battery cables, if you recently had your oil changed or car serviced at a dealership that have a bad problem of not tightening the cables back down I would start there.

Sounds like you’re losing main power intermittently. Check battery cables etc as others suggest…