I think i broke my ECU

[ModifierMR]

ok, this is a continuing problem for me.

Ive been getting 19MPG on my 2003 Toyota Camry LE. I should be getting at least 30MPG. I have a 4 Cylinder Engine for crying out loud!!! I have done a full tune up. High Flow K&N Filter. and removed extra weight. But all in vain!!!

I think this problem started Back in January when i tried to install a Air/Fuel Ratio gauge. But i never got it working and i got impatient so i tried wires blindly coming off the 02 Sensor on the Exhaust Manifold. And i think i may have damaged the ECU . The reason i say this is because everyone is telling me that because my car is a new one, that it would give me a Check engine or error codes. But it doesnt.

So im thinking i damaged the ECU itself. I also blew a fuse to the ECU B4 too. Now if this is the case... How do i fix it? Can i re-program it? Or where can i find a replacement?

Thanks in advance!

Hope somone can help

[drunken_panda]

Does the CEL come on when you turn the key on?

[ModifierMR]

CEL? Does it say CEL or is it a Icon?

[95WhiteCamry]

CEL is an acronym for "check engine light."

the icon should be orange and should say "check" and have a little thing under it.

should be similar...

[ModifierMR]

The reason i say this is because everyone is telling me that because my car is a new one, that it would give me a Check engine or error codes. But it doesnt.

And again, it didnt give me a CEL. Thats why this is such a dilemma. ive run out of ideas. and no i dont drive like a nut. I drive slow...lol

[chronoti]

if you blew the fuse it wouldnt start, check to make sure your wired it back up good, or try and replace the sensor.

[ModifierMR]

lol Autozone said the Sensor was $400...... And when the Fuse blew it was a 15A mini fuse. My clock and guage lights wouldnt work. And a few other things. The Fuse Panel was labeld ECU-2 for the fuse that blew.

[SnakeyeS]

Blowing a fuse is a good thing becuase it will prevent damage to the ECU. Try resetting the ECU by undoing the negative lead on your battery. Let it sit for a half hour or so. When you start it up, drive like you normally drive the the ECU will reprogram itself to your driving habits.

[ModifierMR]

Thanks alot, i will try that

[Cyorke]

Originally Posted by drunken_panda

Does the CEL come on when you turn the key on?

What he is asking is does the light that 95WHiteCamry posted turn on when you turn the key to the on position? It should come on temporarily when you turn the key on. It comes on as the ECu is doing a check of the system and then turns off once the check is done.

You may want to have it checked for codes. SOmetimes there can be codes in the ECu that do not turn on the CEL.

[ShawnM]

Fuses are ment to protect the wiring in a circuit, not the component. The excessive current has to pass through the circuit before the fuse will heat up and blow. So the component (in your case the ECU) could still have been damaged. Anything is possible but I would think the check engine light would be on if you had any serious problems. You could take it to a shop and have them check the O2 sensor readings through the scanner to see if there is anything unusual going on.

[ModifierMR]

Im getting a Oil change today from my mechanic i will ask him to check the codes.

The CEL does come on and then shut off

Also I tried that thing where you disconnect the Negative battery terminal and let it sit for an hour and then re-connect it and try the ecu again. Well it didnt work. Im still getting 19MPG

[SnakeyeS]

^How would you know unless you already burned a full tank of gas?? Calculating MPG must be done right after a full tank fill up. If you recall, the fuel gauge actually goes significantly above the F mark on your fuel gauge when you fill you tank. This means that the half mark is not actually half a tank as there is an offset in the system.

Try calculating like this: Fill up until the gas pump shuts off. Record miles on your trip and note your amount of city/highway driving. Drive it down until you're very close to E. Fill up again and record the # of gallons put into the tank. Take your tank capacity (18.5gal???) - what you just put in which equals the # of gallons left in your tank from your test run. Then you know exactly how many miles driven and exactly how many gallons burned.

[ModifierMR]

i know how to calculate that, but i just know because the needle still moves way to fast throught the gauge

[SnakeyeS]

^ Yeah i figured you did. I'm just saying cause I thought I was having the same problem but i was just calculating it wrong. Before you take in it do a calculation by burning a whole tank. You may be surprised by the results.