X2J Computer

[klemklubfoot]

Hello all

I finally put a X2j computer into my car i had sitting around, and much to my dismay the check engine light came on when it was started.

i am almost positive every thing was taken apart and put together correctly. The car has been parked all winter and ran fine when parked.

So far I have never had this light on before, the car is a 1991 sho with 180 000 kms. and a c&l mass air sensor.

After work tomorrow i will check to see what codes I find.

was there something i should have done when hooking things up to acknowledge this swap?

Thanks for any input

 

[K-Dawg]

Not that I'm aware of. Check the codes. The car does not have EGR, correct?

 

[firstgen89sho]

You can take any MTX computer and swap them between years, now..... the only ones that would be different are the CALI cars as they had EGR on them, and would throw a CEL

 

[klemklubfoot]

Yep I live in canada and I bought the x2j from some guy in the states which would probably mean my car doesn't have an egr, does any body know what i would look for on this computer that would help me to figure out it was a california computer.

wow you guys are good

thanks so far

 

[K-Dawg]

X2J isn't set up for EGR (not a California computer).

 

[jonheese]

Look at your engine. If it has an EGR valve coming from the rear header and going to the rear intake surge tank, you have a CA car.

Or, post the ECU catch code (eg. B9B1) and someone here will tell you if it's a CA ECU.

 

[klemklubfoot]

Alright thanks for the help i will check things out afterwork tomorrow

 

[SHO Continental]

So.............. What's the code?

 

[SHOtime2511]

C&L maf might be the issue.

 

[jonheese]

True. The DTCs will tell the tale.

http://wiki.wikisho.com/wiki/EEC_Self_Test_Procedure

Edit:
The more I think about this, the more certain I am that the problem is probably related to the MAF.

According to my '90 EVTM and Probst book's wiring diagrams, pins 27 (PFE sensor) and 33 (EGR solenoid) would have just been ignored on a non-CA ECU.

In other words, if you put a non-CA ECU (eg. X2J) in a CA car (with the EGR system installed), it would not throw a code. It's not expecting any signal to come in from the PFE sensor on pin 27, and it's not going to complain about not being able to send a signal out to the EGR solenoid on pin 33. The EGR system will be dead weight, but it's "dumb", and doesn't know that the ECU is ignoring it and never telling it to do anything.

The opposite situation does throw a code: Putting a CA ECU into a car without EGR will cause the ECU to freak out when it reads 0 volts and inf resistance on the EGR and PFE pins.

Klemklubfoot: Did you have the C&L MAF installed and working properly before the ECU swap? If so, was there any LPM or chip installed to account for it? Did it have any codes then?

Until you get the codes, this is all guesswork, but I think the MAF is a better guess than the EGR stuff, given my understanding of how the latter works.

 

[klemklubfoot]

x2j continued

o.k sorry for taking forever,

as far as i can tell the car has no egr valve. i am pretty sure i found where it would be because it should be next to the brake filler. the intake in that area is a solid piece of aluminun with no holes, basically not drilled out.

so no egr.

and now I will re read some above posts and see what i can understand


thanks

tyrone

 

[klemklubfoot]

Oh yeah the car ran fine with the C&l before the ecu swap, but afterwards no luck.

"Putting a CA ECU into a car without EGR will cause the ECU to freak out when it reads 0 volts and inf resistance on the EGR and PFE pins."

i am thinking this is the case so far,

i have the x2j out right now, all of the stickers are intact except for the one that goes over the WARRANTY ITEM DO NOT OPEN one. half of the bar code is ripped off

the top code that goes into the harness says

EEC-IV SFI-MA22
F2DF-12A650-AA G
62SM22AM01 17736-58 5D18

hope that means something?

 

[K-Dawg]

I'm pretty sure that a stock X2J is for non-Cali cars only, so you're fine there.

Pulling the codes would probably go a long way to diagnosing your problem.

I think that it's your MAF, and even if it's not, I'd remove it anyway.

 

[klemklubfoot]

I think it is just odd as soon as i put this computer in the check engine light came on, and it has never been on for me in this car, even with the other computer.

I will look into the code thing again it is funny when i did it before i could swear it was giving me 3 digit flashes and beeps. I think it is my lack of understanding how to read what it is telling me. I will keep trying though.

thanks

 

[jonheese]

Oh yeah the car ran fine with the C&l before the ecu swap, but afterwards no luck.

Codes, codes, codes. See the link I posted above if you don't know how to pull the diagnostic trouble codes from your computer.

"Putting a CA ECU into a car without EGR will cause the ECU to freak out when it reads 0 volts and inf resistance on the EGR and PFE pins."

i am thinking this is the case so far

Nope, that's not possible. The X2J is not a CA ECU. The CA ECUs have catch codes like B9B1 (I think) and maybe a couple others. X2J is definitely a 49-state ECU so what I said above does not, cannot, apply.

"i have the x2j out right now, all of the stickers are intact except for the one that goes over the WARRANTY ITEM DO NOT OPEN one. half of the bar code is ripped off

the top code that goes into the harness says

EEC-IV SFI-MA22
F2DF-12A650-AA G
62SM22AM01 17736-58 5D18

hope that means something?

Nope, that doesn't tell us anything, but I have a question: Why are you reading the stickers on the X2J? You already know it's an X2J (does it says X2J anywhere, by the way?)... What else do you hope to find out about it?

You were supposed to look at the catch code (should be a 3 or 4 character alphanumeric code printed in very prominent bold-print on a sticker mostly by itself) on your OLD ECU, not the new one. That would tell us whether it was a CA ECU or not, but if you don't have an EGR valve on your (stock) engine, then that's a moot point, because we know it's not a CA car at that point.

I think most 49-state '91s came with L0S catch-code ECUs, so that's my guess as to what it is.

I'm pretty sure that a stock X2J is for non-Cali cars only, so you're fine there.

Yup. IIRC, X2J is the stock '94-'95 MTX 49-state ECU.

Pulling the codes would probably go a long way to diagnosing your problem.

I think that it's your MAF, and even if it's not, I'd remove it anyway.

+1.

 

[jonheese]

I think it is just odd as soon as i put this computer in the check engine light came on, and it has never been on for me in this car, even with the other computer.

I will look into the code thing again it is funny when i did it before i could swear it was giving me 3 digit flashes and beeps. I think it is my lack of understanding how to read what it is telling me. I will keep trying though.

thanks

You realize that the codes are stored in and generated by the ECU, right?

If anything was going to cause a check engine light, the ECU would be right near the top of the list. But without the specific codes (and you must use the correct procedure to retrieve them, both KOEO and KOER), it's like someone teaching you to make Crème Brûlée by just pointing you towards the kitchen... You need more information or you're never going to just guess the answer.

 

[K-Dawg]

I will look into the code thing again it is funny when i did it before i could swear it was giving me 3 digit flashes and beeps. I think it is my lack of understanding how to read what it is telling me. I will keep trying though.

thanks

The X2J will give you 3 digit codes, so that's right.

 

[SHOtime2511]

correct me if im wrong but isn't the C&L maf the one where you use the stock electronics from your 55mm?

 

[klemklubfoot]

okay the codes i got are as follows

koeo
114 act out of self test range, 157 maf circuit below minumum voltage

koer
111 system pass
9 flashes o.k.

After i ran the koeo test several times to double check flashes, I unplugged the test lead started the car to make sure it was still warm but this time the check engine light did not come on. so I turned car off and set up test lead and proceeded to continue with the koer.

i've seen the code 114 on here before but i will do a search again.

Sounds like it is a good idea to take out the c and l sensor.

Pretty cool how these cars can do a self diagnostic test to tell of problems

thanks everybody

 

[jonheese]

Was it colder than 50°F (10°C) when you ran the self-test? I'm guessing that Quesnel is Quesnel, BC, so I'm guessing it was. If so, you can ignore the 114; it just means that the intake air charge temp sensor reported a <50°F temp. Also, 114 will not trip the CE light, so it's just an incidental code, not your real problem.

The 157 is definitely the primary issue, and as you guessed, it points to your MAF. Have you checked the MAF connector and made sure that it's clean and fully plugged-in? I'd suggest some contact cleaner (Radio Shack) and maybe plug and unplug it a few times. Give that a few run cycles, and if that doesn't help, you might want to visually check the wiring going from the MAF to the ECU, but IIRC the only place where it's really accessible is right at the MAF connector end.

Good luck.