Car Starting Problem (ECM/PCM Fuse)

[LD_Mart]

I need help with my car, about 75% of the time i turn my car off and lock it and then come back to start it, it wont start. It has only happen in the last 2 days. Have done no mods in this time period.

Everything is fine such as battery and stuff. It just wont even crank over.
But i go to the fuse box pull out the ECM/PCM Fuse and plug it straight back in and the car will start fine.

Anyone know what could be causing this problem?

Cheers

[JPR28610]

does it still crank when it doesnt start?

[stndrd]

Could possibly be the engine main relay sticking (if its a honda), tho don't hold me to it. If it's for your WRX it could possibly be keypad alarm related & I would take it back to the dealer

[Setanta]

I don't know about the model of your car, but on older Hondas in hot weather it is often a case that that the solder in the main relay has dried out and the heat exacerbates the issue as there is a lack of connectivity. A good electrician can re-solder the connectors (this is what I did on my EF9 Civic), cleaning up all of the joints. There is a how-to here: http://www.tegger.com/hondafaq/mainrelay.html

On that note, it's the only thing I can think of and doesn't explain the fact that your car will start once you have reset the fuse.

[LD_Mart]

its 2000 EK civic.
nah doesnt crank at all when it doesnt start, almost like the immobiliser is stopping it from starting.
it could be coming from my after market central locking/alarm system. other wise i have no idea.

but thanks for the tips Setanta ill have play around tomorrow.

[Banana_hammock]

The fuse isn't making a solid connection that's why you're not cranking at all. The problem could be as simple as having a dusty fuse/connection and blowing it off can solve the problem

[ECU-MAN]

does the green key flash on the cluster when it wont crank ?

[LD_Mart]

Nup, Just oil, battery, handbrake light come up.

Been playing around with stuff all day and havent found the problem

[ECU-MAN]

do you get 12v at the starter motor solenoid when cranking ?

[LD_Mart]

not sure but i definitely think its the immobiliser, because i unplug it from under the dash and plug it back in and the car will start.

what are your thoughts?

[ECU-MAN]

you need to replace that back box, sounds like it is failing.

[LD_Mart]

if i just replace it with any black box will it work? or is it coded?

[ECU-MAN]

it is coded


its coded to both your black keys and the red key, its also coded to your ECU.


If your 100% sure this is the cause of your problems, I can sell you one and code it up for you. You can also get a new one from a Honda Delaer and have them code it for you as well.