I was wiring an amplifier today and my hex head slipped and came in contact with the ground and positive, it ark'd and immediately set off the car alarm. i used the key fob to stop it, but then when i tried to start the car it would turn fine but not fire up. now the key fob will not open the doors/trunk. Just about every light on the dash is on as well as the 2 front interior lights even with the key not in the ignition. Please tell me i didn't cook the ecu or some BS. i just got this car and cant afford this. the dealer wants $115 to reset the key, or $105 for an hour of diagnostic. nevermind if i fried the ecu. Has any one seen/heard of this before?

 

Check your fuses. Not sure which wire you grounded, but inspect them all. The fuses are there to protect the electronics from surges like you created.

 

The negative battery cable should have been disconnected before starting any electrical work.

Yes, check the fuses first. I would guess at the very least, the No. 7 (10A) fuse in the driver's side under dash fuse relay box is blown.

I think there is more possibility of damage to the driver's side Multiplex Integrated Control Unit (MICU) than the ECU in this case. The MICU is part of the driver side fuse/relax box assembly. The lights staying on may indicate a problem with the MICU. But, check the fuses first to see if it resolves the problems.

There are cases of people installing aftermarket electronics on their car, where the ECU/Immobilizer no longer recognize the keys and needs all the keys to be reprogrammed again; but, they usually don't have the other symptoms you have, other than the car not firing up.

 

BAM!! and im back! i had a buddy come pick me up with jumper cables and for ****s gave it a shot after i pulled the 40amp fuse for the amp, and with a jump it fired right up. still confused how/why the gauges and lights were powered up with no key, but everything is good for now.

 

Yeah, remove battery cables. I learned that after welding my wristwatch band onto the back of the cigarette lighter. It's amazing how hot that gets.

Fortunately for me, it was a 72 Datsun with a wiring schematic that would fit on a 3x5 card. Shorting stuff like that isn't healthy for computers.