Blowing Fuses?

[Kingdom934]

Hey folks.

I'm having some issues with a Gen1 1985 Camry. Since now I'm using my grandparents car more often, I ended up cleaning and doing some checks to the car. I so happen to find a blown (bridge cut inside) blue 15A fuse laying around in the car. I decided it must have come from the fuse panel inside so I checked and I found that the ECU-IG was missing a fuse, apparently the one that I found was suppose to be in there. Having a strange feeling that there was an issue with that, I bought a pack of another set of 15A blue fuses and when I installed a new one in the ECU-IG, it blew right when I turn the key to 'on' (did not start the car though).



The car starts and runs without that ECU-IG fuse, everything to do with car lights seem to be working well (except dome light, opening door doesn't turn on light, have to set it to 'on' to turn on the dome)

Not sure where else I should look, Anybody has an idea on what could be causing the problem? Does having a missing ECU-IG cause issues with the transmission or gas milage?

[TBayToyotaBoy]

Well, the wiring diagram seems to indicate that the ECU-IG fuse has to do with the Overdrive function, and with the ECT (electronically controlled transmission, or something...I drive 5-speeds). Have you had the car on the highway recently? Have you noticed that a) it only has three gears, and b) it shifts gears at a high rpm?

If the car is just for in-town, you'll probably be okay. If you want to cruise the highway, you may have issues...but I may be wrong!

Oh yeah, and your gas mileage may suffer a bit if o/d and the ECT aren't working properly.

[Kingdom934]

Originally Posted by TBayToyotaBoy

Well, the wiring diagram seems to indicate that the ECU-IG fuse has to do with the Overdrive function, and with the ECT (electronically controlled transmission, or something...I drive 5-speeds). Have you had the car on the highway recently? Have you noticed that a) it only has three gears, and b) it shifts gears at a high rpm?

If the car is just for in-town, you'll probably be okay. If you want to cruise the highway, you may have issues...but I may be wrong!

Oh yeah, and your gas mileage may suffer a bit if o/d and the ECT aren't working properly.

Oh my gosh, that hit the spot DEAD ON

I was thinking...ECU is related to the electronic system. About 2~3 years ago the transmission started to have some issues, Drive and 2 gears have a lot of engine revving and little acceleration. I think that was also the time where I started to see that burned 15Amp fuse in the car.


Currently, It feels like both the Drive and 2 are stuck in what ever the highest gear they are in. What I have to do is launch the car in 'L' to get it up to around 20~25MPH before I switch to '2'. Steep hills are impossible, I was flooring it in '2' and I ended up stop going up and had to throw it in 'L' to climb. Merging from onramps can be quite dangerous at times.

If I do go from a stop to 60MPH in either '2' or 'D', it appears that there is no gear shifting going on, just a lot of revving and time consuming process.

I talked to another friend of mines and he said that the problems I had sounded like something wasn't engaging correctly or something to that line. Problem with the ECT fits that right on the spot.

O/D is non-existent by the way.


Is there any fix to this problem? Blowing out that fuse doesn't sound like something is going right, like a short in the system. I know for a fact that the fuel economy is down at lease by 40%~70% as I have gone down low as 150 miles traveled and used up nearly the whole tank.

Thankyou for your reply!

[timebuilder]

Fuses are there to protect wiring and components. Something is causing a high current draw, and you'll have to take it a step at a time with the diagram to find it.

[TBayToyotaBoy]

Timebuilder's right...you'll have to a) visually inspect the wiring harness for any obvious signs of fire/damage (unlikely), then start testing the wiring. Maybe start by locating the grounds for that part of the system. There may be a corroded/broken ground wire on the transmission or ECU itself...just be patient.