Did I just fry my ECU on my new car?

[snb778 5,000+ posts]

Ohhhhhhhhh boy..start the flame fest, but I do reallllly need help badly

So I accidentally hooked up the battery terminals on the opposite posts for like 30 secs..... I know, stupid me, im an idiot, how did I do that.. blah blah blah... ITS DONE.... noticed my headlights were on, which is weird because the switch was off...

ANYWHO... i noticed it, changed it to the proper hook-up, and now NOTHING on my car works. weird thing is, as I said, when it was hooked up reverse, the headlights were on, and did work......now they don't

I'm confused on testing the fuses, because 9/10 of them don't light up, but they all appear to be fine... There are a few here and there that do light up. Doesn't this happen on reverse polarity cars? (or negative polarity)

anybody know how I can check my ECU to see if its fried?

any suggestions TO FIX IT or troubleshoot would be great

Click to read more...

 

[fatboyracing 10+ year member]

do you have a mm if so pull each fuse and chech them with ohms

 

[shizzzon 10+ year member]

on a newer car, i would lean toward the computer NOT being damaged. there are so many fuses on newer cars these days that there are fuses for the fuses and fuses for the fuse box which hold the fuses to prevent the other fuses from fusing...hehe.

Seriously though, you may have more than 1 fuse panel, i do in my car.

Check under the hood for the MAIN one. this is the one that will at least start your car i believe.

Check under the steering column or glove box for the other fuse box. This one normally controls interior lighting, etc...

 

[snb778 5,000+ posts]

isnt there a way to do it while they are in the car?

 

[snb778 5,000+ posts]

on a newer car, i would lean toward the computer NOT being damaged. there are so many fuses on newer cars these days that there are fuses for the fuses and fuses for the fuse box which hold the fuses to prevent the other fuses from fusing...hehe.
Seriously though, you may have more than 1 fuse panel, i do in my car.

Check under the hood for the MAIN one. this is the one that will at least start your car i believe.

Check under the steering column or glove box for the other fuse box. This one normally controls interior lighting, etc...

its not a newer car.. its an 01 escape

I know where the one under my hood is.. .just getting really weird test results.... 2/10 light up, but the ones that don't-- appear to be just, fine, and NONE of the ones inside my car light up...which leads me to believe either A. I fried my ECU, or B. The car is negative polarity

 

[shizzzon 10+ year member]

oh man, i had a 7.5 A fuse blow on me not too long ago. visibly it looked fine but had no continuity. If it doesnt pass the ohm check, it's BAD.

Replace ALL fuses that have no reading.

 

[snb778 5,000+ posts]

oh man, i had a 7.5 A fuse blow on me not too long ago. visibly it looked fine but had no continuity. If it doesnt pass the ohm check, it's BAD.
Replace ALL fuses that have no reading.

what reading should I get on ohms?

 

[whitedragon551 5,000+ posts]

Are you sure it didnt discharge the battery and its not just dead because it had a bad ground?

 

[snb778 5,000+ posts]

yep... still at 12.78

Just took out 1 fuse that didnt go on with test light, and 1 fuse that DID go on with test light... both read 0.0 @ohms in AND out of car

 

[shizzzon 10+ year member]

It should read 0.0 ohms.

If u have a multimeter that consistency reads 0.0 ohms until u try to measure a load, then it must be able to make a sound if u get a real 0 ohms or else u wont know if its good or not.

 

[shizzzon 10+ year member]

oh and ur batt reading 12.78, that doesnt mean it's fine.

I've measured normal lead acid batts at 12.5v that couldnt even power the interior dome light!

if u cant start the car with symptoms that sound like battery discharge, you NEED the batt tested at AutoZone.

They can run a discharge simulator based upon the CA rating of the batt. If it doesnt recover to a certain voltage after the simulation, then the batt is damaged and cant hold a charge anymore.

 

[snoopdan 5,000+ posts]

does the vehicle try to start when you turn the key? how about wipers, headlights, break lights...etc? does that still work?

 

[HeadCase 10+ year member]

Your ECU is perfectly fine. Your ECU does not control any of the electronics that are not related specifically to the engine.

Your issue lies else where.

 

[SicAudio 5,000+ posts]

use a test light hook the clip to ground and probe both sides of each fuse or manually pull each fuse and visually look at it. you probably just blew the main cb fuses.

 

[snoopdan 5,000+ posts]

just read what you wrote again, have fun looking for fuseable links!