Go to an autoparts store and use their code scanner, it will plug into the OBD port and report back with what the code is.

You can check the check engine light manually, to do so get in your vehicle and have the key in the ignition. Turn the key to ACC then turn it back to the off position, do this three times in a row but on the third turn leave the key at ACC and watch your CEL. It should be illuminated for a few seconds then turn off and begin to blink. You'll need to count the number of times the CEL blinks in a row, every pause between blinking is a different CEL code being transmitted.

It is best to have a repair manual on hand to match the number of CEL blinks to the check engine code.

A ECU that is starting to go bad may still allow the vehicle to start but its highly unlikely, but like totaleclipse_05 mention just take it to a local auto parts store and use their scanner.

No need to jump to a bad ECU

my apologies I didn't check your profile to see what gen you were referring to. I've only done that trick on a 2gNT Eclipse never a 1g but you could give it a try.

Get yourself a 12v light bulb/buzzer and some wires, hook it up so if you complete the circuit on a 12v batt, the light illuminates or the buzzer sounds. Connect these two wire ends to pin 12 and 1 at the test port next to the fuse box, under the drivers side dash. Turn the key to the on position, and the light will flash/buzzer will sound long, then short sequences. Long are the first digit of codes, short-rapid flashes are the second digit. (e.g.- 3 long flashes followed by 1 short flash means: code 31)
Further codes will start after the first, then when the all codes have been gone through, it will repeat them, starting from the first code.

Pic for reference, courtesy of google.


For instance, I use a 12v led with two alligator clips.

totaleclipse_05 said:

Go to an autoparts store and use their code scanner, it will plug into the OBD port and report back with what the code is.

Click to expand...

Hes obd 1. Autoparts store wont do it.

tametalon92 said:

Get yourself a 12v light bulb/buzzer and some wires, hook it up so if you complete the circuit on a 12v batt, the light illuminates or the buzzer sounds. Connect these two wire ends to pin 12 and 1 at the test port next to the fuse box, under
the drivers side dash. Turn the key to the on position, and the light will flash/buzzer will sound long, then short sequences. Long are the first digit of codes, short-rapid
flashes are the second digit. (e.g.- 3 long
flashes followed by 1 short flash means: code 31)
Further codes will start after the first, then when the all codes have been gone through,
it will repeat them, starting from the first code.
Pic for reference, courtesy of google.

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For instance, I use a 12v led with two alligator clips.

Click to expand...

This is my problem when I touch my clips the the pins the light doesn't light up at all same with directly at the ecu I could biy a buzzer and try it but if there is no signal at the wires it won't do anything either correct?

Test with a multimeter at the pins to see if you have any voltage, use pin 12 as your meter ground. Check at the ecu pins as well, and check continuity between the ecu and diag. port to ensure you have the correct wires and they're not cut/broken.

If you still have no voltage at that point, the ecu may be damaged internally. It's entirely possible for the car to have a bad ecu and still run, leaking capacitors that corrode/damage the board is a major issue with these older dsm ecus.

talonbooster123 said:

This is my problem when I touch my clips the the pins the light doesn't light up at all same with directly at the ecu I could biy a buzzer and try it but if there is no signal at the wires it won't do anything either correct?

Click to expand...

Just curious you do have the key on?

tametalon92 said:

Test with a multimeter at the pins to see if you have any voltage, use pin 12 as your meter ground. Check at the ecu pins as well, and check continuity between the ecu and diag. port to ensure you have the correct wires and they're not cut/broken.

If you still have no voltage at that point, the ecu may be damaged internally. It's entirely possible for the car to have a bad ecu and still run, leaking capacitors that corrode/damage the board is a major issue with these older dsm ecus.

Click to expand...

I picked up an analog multimeter today and a another voltage detector with light and buzzing feature so I will try both of those again but I tried with a digital multimeter before and couldn't get any readings whatsoever

pauleyman said:

Just curious you do have the key on?

Click to expand...

yes I have the key turned to acc when I'm doing this

No. You must turn it to on.

talonbooster123 said:

yes I have the key turned to acc when I'm doing this

Click to expand...

pauleyman said:

No. You must turn it to on.

Click to expand...

Oi....well hopefully this solves the issue.

Well considering the ecu has no power otherwise

tametalon92 said:

Oi....well hopefully this solves the issue.

Click to expand...

Ahhhhh, I will try tomorrow hopefully that's the issue! Least it might be something simple for once.

So I tried it with the key turned to on and acc and no difference

Pull the ecu and have a look inside for obvious damage.

pauleyman said:

Pull the ecu and have a look inside for obvious damage.

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Okay I will try that next, might be a little while before the next update, never took an ecu out before either would obvious damage be something similar to a fried amp? Black pieces bad smell ect?

Yes. You need to find out if the wiring is intact. Something obvious has to be wrong

Only two possibilities I see are bad ecu or wiring issue between ecu and the port. Or you're checking the wrong pins....guess thats three

Hey guys sorry it's been so long since an update I'm in the middle of moving 6 hours away to another town so been really busy. I had time to tinker with it today and here are my results. Test light didn't work, test buzzer didn't work, analog multimeter wouldn't work. Managed to get some numbers with a digital multimeter but it's hard to read the pulses like that. I hooked it up to a speaker that's worked best so far but again very hard to hear/read. I'm going to look for a better analog multi meter tomorrow. Here us a video of the speaker if you guys would like to hear it or even possibley decode it for me that'd be great! Here is the link: https://vid.me/uKEF

You have got to be reading the wrong pins....and you just hooked up a coil to a voltage source? Bad idea.

pauleyman said:

You have got to be reading the wrong pins....and you just hooked up a coil to a voltage source? Bad idea.

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I'm reading pins 1 and 12 like the manual says, by coil you mean the speaker? Someone said to try it in another thread so thought id give it a try. Why isn't that a good idea?

What range are you using on the analog meter? Im starting to think this is user error.

pauleyman said:

What range are you using on the analog meter? Im starting to think this is user error.

Click to expand...

Nothing was working other than the speaker and the digital one before but
I picked up another analog meter today and this one actually works. What should it be set at? just put it to 10v as that moved the needle the most. I have a video of it but my camera wouldn't focus but you can still see could you take a look and tell me what you think? Heres the link: https://vid.me/DQcc

20 would be easier to read as 10 will bury thr needle. It will be obvious what works best

talonbooster123 said:

Nothing was working other than the speaker and the digital one before but
I picked up another analog meter today and this one actually works. What should it be set at? just put it to 10v as that moved the needle the most. I have a video of it but my camera wouldn't focus but you can still see could you take a look and tell me what you think? Heres the link: https://vid.me/DQcc

Click to expand...

Based on that video, you've got two codes: 12 for the mass air flow sensor and 31 for the knock sensor.

19Eclipse90 said:

Based on that video, you've got two codes: 12 for the mass air flow sensor and 31 for the knock sensor.

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I will look into those thank you!

pauleyman said:

20 would be easier to read as 10 will bury thr needle. It will be obvious what works best

Click to expand...

Okay I will try 20 next time thank you