Hey guys,

Just recently, I keep blowing this fuse (Number 8 in the picture) and im not too sure why it keeps blowing?



When it does blow, the car will cut out and drop back to reds so im not too sure what it correlates too.As soon as I replace it, car starts up again no problems. If I dont replace it, you will hear the car crank but obviously wont fire up. Didnt test for spark but simply replaced the fuse which fixed the problem. Note that its about 30mins worth of driving for it to re-occur.

So not too sure what fuse #8 is but is it fuel pump? Or is it spark?

Further, what would this problem be as nothing has changed other than having to pull out the centre console and putting it back?

Cheers

 

That's the ECU fuse, commonly pulled to reset the fuel trims.

Honestly I can't tell you what else is on the circuit, but is there anything aftermarket wired into the ECU or that circuit?

 

hmmm

 

Only other things wired to the ECU harness include the Wideband AEM and my EVC 6...

So that particular fuse definitely is the ECU? Then what is the big one labelled ECU?

 

Sounds like a wire may have cut and shorted to b+ or b-... That is if no other wires have been touched since this started happening... My bet is a short... If the console is the last thing you touched before this started happening i would personally remove it again and insure all wires are intact and wire sheilding is also not comprimised.. If that fails i would reccomend looking up the circuit and actually measuring resistance for shorts or opens while shaking the harness... Good luck

 

Looks like I may have to pull out all the wiring behind the stereo as the EVC and Wideband both get there power from there.

From memory now that I think of it, the wideband isnt connected to the ECU, only the EVC. The wideband however does have a PC connection in which the grounding wire goes onto the metal bracket holding the ECU case?

Still curious if it definitely is the ECU 20a fuse I keep shorting given there is a big ECU sign in the bottom right corner?

I will test tomorrow as I pulled out the centre console and checked over. All looks good there?

 

The ecu sign in the bottom right displays ecu transistor... As for the fuse it definently for the ecu and protects at least one circuit for the ecu... Do you have a evo 8 or 9. If you have a 9 i will look at the wiring diagram for you as the 8 may have slight differences... Then you will kbow what circuits/ components that fuse protects... I still think you may have shorted a wird out to ground as the only change was removing the console...

 

As stated above, something on that circuit is causing that fuse to blow. I would remove all aftermarket parts to isolate the problem then go from there.

 

Thanks for the advice guys. Im going to have a look into it this evening as there were some stereo wiring changes 2 weeks back that I will just go over to be on the safe side.

Cheers

 

Fuse #8

Cooling system
Immobilizer system
Manual Air Conditioning system
MFI system

 

Ok so I checked all the wiring behind the stereo and made it more tidy.

Replaced the fuse and took it for a drive. All went well then the fuse went again. Ive noticed its on exiting out of a corner on low speed where the fuel on the wideband pegs far rich.

Is this a mechanical issue with the fuel pump which is causing the fuse to short? Everytime it shorts its when the fuel pegs rich and the revs dip

 

Fuse #8 protects the following...
crank sensor
egr solenoid valve
engine control module
evap vent solenoid
evap purge solenoid
exhaust cam sensor
fan relay
fuel pressure solenoid
heated o2 sensor
idle air control motor
immobilizer-ECU
intake cam sensor
injector resistor
MFI relay
oil feed control valve
turbo wastegate solenoid
volume airflow sensor


As you can see it protects alot but does not protect the fuel pump as was in question for issue (fuse 15 protects the fuel pump)

One of those above circuits is causing your issue...

 

is ignition stock?
what changes did you make to trigger this problem?

 

It is your rear O2 sensor. The wires are frayed and its grounding out on the chassis. Get under the car and fix it.

Typically becomes more noticeable when it rains and the water helps complete the short circuit.

 

Had the same problem and this was the cause.