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ECM possible problem

Hello there, hope somebody can help me with this. The check engine light in my Tacoma '97 stopped working and the scanner cannot detect any signal from the ECM, also don’t have any spark. I have changed almost everything related to the ignition except for the igniter and the ECM. Is it possible that my problem is due to a malfunction of the ECM?

I have the same problem, except 01 pontiac grand prix. changed icm/igniter, coils, crank sensor, checked for bad connections…everything i can think of. question? does yours start at all? if it does start, does it run for a little bit and then die with no power after that to the coil packs causing no spark? i even put it on a scanner and came back without an answer. my next step is the ECM, let me know what yours is doing please. maybe between the two of us we can come up with a solution to our problem.

It’s also possible that your ECM isn’t getting any power due to a faulty wire, connector, switch, or blown fuse. Have you verified that it is getting all of the correct power and ground connections?

would the vehicle start at all if therre was a bad ground? and where do you find out what the power rating should be to the ECM?

I agree with Tardis’s thinking. This trouble sounds like a power supply issue. Check the power supply to the ECU and make sure that is ok. Check the fuses in the dash and under the hood as a first step.

Vernon… you need to start your own thread. Your Pontiac is a completely different system that has no relevence to this problem.

I know what is wrong with your car and I will be happy to help in your own thread.

I was answering for the OP’s problem, not yours. Yours is different.

thread is no spark. dated 1-21-10

If you have a V6 make sure your timing belt isn’t broken.

It’s certainly possible that the ECM has died, but it’s more likely that it is not getting power. ECMs are often on a power line that is fused, and the fuse often is labelled in a way that gives no real clue that the computer is on the line. On our 1995 Neon, the computer was on the “Radio” fuse. In our 1999 Toyota, it is, as I recall, one of the EFI fuses (There are two if my frequently faulty memory hasn’t failed me). I’d check all the fuses before I started dinking with the ECM. Better yet, find a wiring diagram and see if you can identify the fuse, or at least find a connector where you can check for power to the ECM using a cheap voltmeter or a test light.

“The scanner cannot detect any signal from the ECM”. Check the ADL connector, under the edge of the dash, where the scanner plugs into. Check pin #12 (white/red wire) for the presents of 12 volts when the ignition key is in RUN. If there is not 12 volts there, the ECM will not be powered, nor the scan tool.

Hey guys I really appreciated all the input. Well the only thing left for me is to check the power to the ECM, all the fuses had been checked, and yes the truck turn but it won’t crank, as soon as I fixed I’ll post what was the problem, maybe some else can use as reference. Again thank so much!

Hey there, sorry took me this long but I lost the freaking password, anyway, my truck still sitting still cannot find solution, but I tell you what do not buy de ECM just yet, it is expensive! Just make sure about everything else first. I got me a used ECM but didn’t solve my problem. Now the “checking engine” light is no even light. Now my problem is very similar to yours, so if you find a solution hit me back and shed some light on me, please! Good luck with your car.

You might check the AutoZone website for a wiring schematic. Personally, I don’t care for the AZ site as it’s a bit unwieldy and prone to lockups, along with inaccuracies.
A quick look shows the EEC system is powered through at least 5 different fuses and links so you need to make triple sure that all fuses and links are good; with a test light preferably.

The CEL light is powered through a fuse (so are the ignition coils) and through the ignition switch so if the CEL is not working that means there is a supply problem.
You should also consider the possibility of a failing ignition switch. (electrical part)

As hard as this may be to believe, it’s a fairly safe bet that this entire problem is going to be something very simple. It usually is.
(And this is assuming that used ECM is a direct match for the one you removed)

You have not stated that you have used a voltmeter, multimeter, or even a test light to check for power (12 volts). Does this mean that you haven’t, and that you won’t?

And you need the wiring schematics which show the power circuits. Have you made any efforts to get, and use, those?