So the other day I was getting my car pulled to a friends house to have him weld me a down pipe, and half way there, me ECU started making a loud buzzing noise. It's only when I turn the key all the way forward. I haven't tried to start my car yet because I don't know if I should. Does anyone know what the problem could be?

C'mon. Someone has to know

Never heard of the car ECU buzzing. Probably the start to the self-destruct-sequence.

WDRacing wrote:Never heard of the car ECU buzzing. Probably the start to the self-destruct-sequence.

So... I guess I need to get a new ECU. Do you thing pulling the car could have had anything to do with it. Also, when I turn the key all the way forward, my tach goes up to 4k and stays there.

Do you think it would be ok if I tried to start my car

I'd be willing to bet money on it being one of the relays over there and that you have a bad ground. Double check your grounds and see if anything happens.

the converted wrote:I'd be willing to bet money on it being one of the relays over there and that you have a bad ground. Double check your grounds and see if anything happens.

Thanks I'll check my grounds when I get off work.

I was also thinking that it had something to do with me using the brakes while the car wasn't running. If i press the brakes while the key is turned forward, it will make my tachometer jump and the sound will get louder until I let off

That is without question a grounding issue. Good luck finding it.

the converted wrote:That is without question a grounding issue. Good luck finding it.

Well, I just got done checking all of my grounds with a multimeter and they were all fine

A multimeter isn't a good way to test because it won't account for the amount of current flowing through a ground. Disconnect the grounds and sand them down to see if anything changes.

the converted wrote:A multimeter isn't a good way to test because it won't account for the amount of current flowing through a ground. Disconnect the grounds and sand them down to see if anything changes.

Ok thanks, will do.

I ok, I sanded down all of my grounds and I'm still having the same problem.

Really strange. So tach jumps when you hit the brakes, and there is a relay buzzing by the ecu. Are there any other odd symptoms that you have noticed? I'm about to go look at the electrical diagram and see if there's anything the might be obvious from that point of view.

Also, have you checked the chassis to battery and engine grounds under the hood?

abs?? i dont think there are any relays in the ecu... there may be some around it. try to pin point the sound. feel exactly where its coming from. i would agree with "the converted", somewhere grounding is going crap. loose connections, weak battery, i had this once coz i had a phone charger connected to the phone and turned the key off.
Modified by trackslut240 at 4:22 PM 10/8/2009

the converted wrote:Really strange. So tach jumps when you hit the brakes, and there is a relay buzzing by the ecu. Are there any other odd symptoms that you have noticed? I'm about to go look at the electrical diagram and see if there's anything the might be obvious from that point of view.

Also, have you checked the chassis to battery and engine grounds under the hood?

Whenever I turn the key forward my tach automatically goes up to 3-4k and if I press my brake pedal it will go up even farther. IDK what is buzzing, but it is coming directly from where the ECU is. When I go to start the car, the noise dies down, but it won't start. It will crank though. I will check the chassis to battery and engine grounds tomorrow, what should it read exactly. I appreciate the help

Should I just get a new ECU. I don't want to put in a new ECU and have the same thing happen again (whatever the problem is )

Exactly, don't swap in a new ECU until we find out what happened, hell might not even BE the ECU.

Unfortunatly I absolutely hate wiring issues. When I get them, I rewire whatever is broke or disconnect whats broke. Obviously not an option in your case.

OK, so your car was in running condition, then you started installing a turbo. The only changes made being exterior bolts ons right? No SAFC, No MAF swap, No injector clips...etc, right?

WD

The more and more I think about it, the more I'm thinking Chassis to battery ground issue. The only way that I could find that the brake lights which ground out in the trunk would effect the tach is if the whole chassis was back feeding through the engine wiring harness to get to a ground. Did you move your battery to the trunk when you did the turbo install?

chassis harness over the front passenger tire? have you moved it after lowering the car? If not check for a short there.

WDRacing wrote:Exactly, don't swap in a new ECU until we find out what happened, hell might not even BE the ECU.

Unfortunatly I absolutely hate wiring issues. When I get them, I rewire whatever is broke or disconnect whats broke. Obviously not an option in your case.

OK, so your car was in running condition, then you started installing a turbo. The only changes made being exterior bolts ons right? No SAFC, No MAF swap, No injector clips...etc, right?

WD

Yeah, my car was in perfect running condition before I started to turbo it. The only change I made besides exterior bolt ons was extending the wires coming from the MAFS so it could reach over to where my TB is.

the converted wrote:The more and more I think about it, the more I'm thinking Chassis to battery ground issue. The only way that I could find that the brake lights which ground out in the trunk would effect the tach is if the whole chassis was back feeding through the engine wiring harness to get to a ground. Did you move your battery to the trunk when you did the turbo install?

Nope, battery is still in the stock location.

MagikDragon wrote:chassis harness over the front passenger tire? have you moved it after lowering the car? If not check for a short there.

I'm sorry but I don't really know what your talking about.

The ground wire from the battery to the chassis is where I would look. Sean is talking about the wiring harness in the wheel well. Some of the slammed crowd has issues with the tires rubbing through the insulation on those wires.

the converted wrote:The ground wire from the battery to the chassis is where I would look. Sean is talking about the wiring harness in the wheel well. Some of the slammed crowd has issues with the tires rubbing through the insulation on those wires.

Oh, alright. Yeah my car isn't that low. Do you think it's because I extended the wires coming from the MAFS?

Unless you shorted them out, I really don't see how it could be possible. And just for the hell of it, have you checked the voltage in the battery?

opps i meant over the driver side not passenger side.. But yeah My car rubbed through some wiring, but only after intense race sessions. Its worth a shot. My Gauge cluster buzzes now because of it so I would double check for wear.

the converted wrote:Unless you shorted them out, I really don't see how it could be possible. And just for the hell of it, have you checked the voltage in the battery?

Battery voltage is good, I've double checked every ground and I still have the problem It's really weird how the car was fine and then like half way down the road it justed started buzzing really loud.

Like I said earlier, I had my car pulled to a friends house to get a downpipe made. Eventually after I used my brakes for a few minutes, the pedal got super stiff and shortely after was when the buzzing started. Also, when I jacked the front end of my car up earlier this week, I noticed that my front wheels are almosted locked and if I try to spin them, I hear scrapping noises, like my brakes are locked or something.

Is there some kind of light or something that is suppose to light up on your ECU when you turn the key forward. I thought there was suppose to be some kind of red ring or something because mine has nothing.

If I can't figure it out by next week, I'll probably take it to a shop

If it's any help, I can video tape what I'm talking about, and then tomorrow, post the video on here.

Reset your ECU. Disconnect the battery (-) cable for an hour and reconnect it. If it still buzzes. Try turning your car on, it wont hurt it. When you turn the key to the acc. position it sends power to the ecu anyway. I have a 95 ECU in my 97 and It used to buzz. I flicked it really hard and it stopped.

Hola. Tengo el mismo problema con mi Altma 2000. Accidentalemente hice un corto con los 3 cables del MAF y ahora cuando pongo la llave en ON el relay de la ECM zumba y el tachometer va a 7k RPM y el coche no arranca. Ya he desconectado el MAF y cambie la ECM y sigue el mismo problema ¿alguien sabe algo de este tema?

Hi. I have the same problem with my Altma 2000. Accidentally I made a short with the 3 cables of the MAF and now when I turn the key to ON the relay of the ECM buzzes and the tachometer goes to 7k RPM and the car does not start. I have already disconnected the MAF and change the ECM and follow the same problem does anyone know anything about this issue?