90 Honda Accord

did you replace it with a new one or a used one?

Ignition switch?

It sounds like you lost power to the ECU. There are multiple location where power enters the ECU. No power, no spark, no fuel. Does the check engine light comes on then goes off and able to retrieve codes? Secondly, got signal from the crank sensor?

When I turn on the ignition, the check engine lights stays on the whole time. How can I find out whether the ECU powers up?

Thanks for your help.

Burt S. wrote:

"Gero00 via CarKB.com" wrote in news:5616e315198b0@uwe:

If your Check Engine light comes on, your ECU *IS* "powered up".

Honda ECUs are reliable like the sun. Don't change it.

Check for error codes stored by the ECU: Pull carpet back from passenger footwell. See the red LED? Turn ignition to ON, but not to START. If LED flashes, codes are stored. Count flashes. There may be both long and short. Sequence will be separated by long pause. Multiple codes may be stored, so watch carefully.

Long blink=10 Short blink=1 Sequence long-short-short-short-short=code 14.

Your symptoms sound like a bad ignition switch or igniter. does your tach act oddly?

I checked the error codes stored by the ECU, and I found code 14, which is the Idle Air Control valve. The code was there before the car stopped working, though. I replaced the ignitor and the ignition coil, neither of which helped. I checked the ignition switch by turning it on, and the engine light, the battery light and the oil light came on. I still only get 1 click on the main relay.

If I ground wire 8 on the main relay, the fuel pump starts working. I still don't have a spark, though.

I'd appreciate it if you had any other ideas. Thanks!

TeGGeR® wrote:

"Gero00 via CarKB.com" wrote in news:56244fcf5b230@uwe:

That doesn't mean the ignition switch is OK.

It's still the main suspect.

I think I see your problem. If you turn on the ignition, you hear one click, the check engine lights stays on the whole time, no code

Honda ECU's use multiple power inputs for a reason. To warn us.

The main power to the ECU originates before the main fuse, near the battery. Check for corrosions or wiggle any wires to make the check engine light go out while the ignition is switched ON. Once the light goes out, it should start.