View Full Version : Removing the ECM

07-13-2010, 06:20 PM
how do I remove the ECM?

Or at least, where is it?

07-14-2010, 12:09 AM
I don't know where it is on 6th Gen's, but on 5th Gens, it is below the dash, in front of the console. If you pulled the carpet back just a little to the right of where the console ends, and where the heat duct is, it is right there in the middle. But again, this is on 5th Gens, not sure about yours.

Why are you looking to find the ECU anyway?

07-14-2010, 12:37 AM
I'm thinking that maybe this whole thing is possibly caused by the ECU. I'm going to see if I can see anything visibly wrong with it.

07-14-2010, 12:46 AM
What do you mean, "thinking this whole thing is possibly caused by the ECU."? Do you have a problem stated somewhere in a different thread?

07-14-2010, 02:36 AM
Well the problem that you commented on before, and the intermittent cutting off, and the random throwing of codes 12, 13, 14, and some other also random codes. and now it's not even throwing any codes.

07-14-2010, 11:57 AM
Ah, you are the one that has the very fast idle with the loud sucking sound coming from the IAC valve. Now I got it.

Codes 12, 13 & 14 are all ignition signal codes relating to inputs to the ECM. Sure, your ECM could be on its way out, but I haven't heard of too many ECM defects in Toyotas. If you can get the correct matching ECM for your car and see if everything clears up, that would be great.

Otherwise, I would concentrate on wiring issues between the distributor/igniter and the ECM. Could be that your wiring harness is at fault here. A person previously could not keep is engine running, and the problem was trace to the IGF or IGT wire (can't remember which) that was getting interference by some other wire in the harness, so the ECM could not pick up the signal any further. The solution was to cut this wire from the source (igniter) and end (ECM), and run a new wire between these two points outside of the harness. With no interference, the signal got to the ECM, and solved the problem. You may be experiencing something like this, especially if you have done work involving the igniter, ECM, or distributor that might have caused old & crumbling wire insulation to break off.

07-14-2010, 02:44 PM
Interesting. So you're saying I should try to run new wire to the ECM, from the points of the codes, ex. IGF from igniter to ECU, just run a new wire?

07-14-2010, 08:54 PM
Interesting. So you're saying I should try to run new wire to the ECM, from the points of the codes, ex. IGF from igniter to ECU, just run a new wire?

Only if you have a specific code, and did a complete diagnostics on that source wire to determine there was some kind of interference coming across it by the time it reaches the ECU that wasn't there at the source. I don't think you've done that yet, and I wouldn't recommend this fix unless verified by diagnostics. Otherwise, you are just asking for more problems down the road.

07-15-2010, 12:37 AM
okay. I have a feeling that there isn't a problem in the wiring anyways. I just have this gut feeling it might be distributor or ECU.

Out of curiosity, does this site have a wiring diagram for the 94 celica?

07-15-2010, 01:26 AM
does ur car ramdomly die sometimes if so dat was happening to me and it was the distributor

07-15-2010, 02:14 PM
^ yes. very randomly. and then it may or may not start up with lots of trouble.

07-15-2010, 03:33 PM
did you find the ECU? like mentioned its in the center section behind and below the radio. if you pull back the carper on the passenger foot area, you will see it. its mounted with 2 brackets and a few screwes. its tought to get out, but you can easily pull the plugs out and plug them into another ECU.

07-15-2010, 05:27 PM
yeah I found it. But I'm thinking that johnny's right. the codes it's throwing related the missing signal from the G and NE circuit, which leads to be either the dizzy or the ECM. So i'll replace the dizzy first, and if that doesn't fix the problem, I know what to blame.