is my ecu fried ? need help !!

[247shuer247]

ok guys so i need your help

when i get in my car and turn on the battery i hear the incredibly loud
buzzing noise under the hood. coming from multiple locations. sounds like it could be coming from the pgm-fi box and the fuse box.

also all of my lights on the dashboard come on and stay on nd my rpm meter shoots up to 3000 rpms

im scared to even try and turn it on i dont want to fry anything.
one of the members suggested i disconnect my idle control valve but i wanna get some second opinions first

my ecu took a hard hit a few days ago which is why i suspect it is the ecu

has anybody else had a similar problems let me know thanks guys

[POS carb]

I suspect a bad battery to chassis ground. follow the negative cable to the body. try cleaning up the mounting points.
i don't think the IAC has anything to do with it.

[ShyBoyCA6]

Car wouldnt turn on with the ecu fried. Do what pos carb posted and post back what happens after. All the lights are on? Check for codes that may lead to 3k rpm.

[gp02a0083]

what do you mean by a hard hit? I agree with POOS carb as well, i would suspect the battery. The buzzing sounds could be the mechanical relays trying to work from not getting enough voltage. Many people think ecu's are made of glass or something, they are for the most part through hole components and are fairly sturdy

[POS carb]

1. get a volt meter.
2. turn on parking lights. check voltage at the battery posts (make sure you're on the battery posts, not the cable terminals)
3. if less than 12v recharge and recheck. if voltage is ok go to step 4
4. Ground check: check voltage between positive battery terminal and chassis bare metal. if voltage is significantly lower you have bad/corroded connections on the negative. if voltage stays close to original value check between the batt positive and negative to the valve cover bolt. if voltage drops you have a bad engine ground strap.

5. Positive check: check voltage between battery negative and positive on main fuse. If battery voltage is significantly lower you have corroded positive terminals.

[POS carb]

there is no code that will cause 3000 rpm. when you have bad grounds all the power tries to find it's way through whatever it can, like relays and gauges

[247shuer247]

just an update guys i found the problem it was a grounding failure lol.

so the car starts right up and idles a little high
but my main concern is should the ecu lights blink even when nothing is wrong ?

because i wanted to check the ecu codes but no led lights flashed ??

is there something wrong with this ? should i look into it ?

[247shuer247]

1. get a volt meter.
2. turn on parking lights. check voltage at the battery posts (make sure you're on the battery posts, not the cable terminals)
3. if less than 12v recharge and recheck. if voltage is ok go to step 4
4. Ground check: check voltage between positive battery terminal and chassis bare metal. if voltage is significantly lower you have bad/corroded connections on the negative. if voltage stays close to original value check between the batt positive and negative to the valve cover bolt. if voltage drops you have a bad engine ground strap.

5. Positive check: check voltage between battery negative and positive on main fuse. If battery voltage is significantly lower you have corroded positive terminals.

thanks for this it really help alot