CEL on, no codes stored?

[TwIzTeD_3kGt]

This just started happening out of the blue. Hadn't flashed anything for a couple days, then yesterday afternoon I start it and the CEL is on. I used a scan tool to check the code, no DTC's found. I cleared it, it was gone on the next start up. The next start up, it was back again, no DTC's found again. I drove it, drove it hard, CEL went out. Next startup it's back on.

Any ideas?

[Greg E]

Evoscan 2.9?

[TwIzTeD_3kGt]

Evoscan 2.9?

Yes. I checked the codes with a hand-held scanner though, not Evoscan if that's what you mean. I know it doesn't read codes correctly.

[Greg E]

The scan tools don't know how to read all the CEL codes. I used to remember what the codes were that your average scan tool couldn't read...

Anyway, what is your periphery 2 setup?

[Autochef]

Same problem here, I also use 2.9 and use a scanner, but it pops back on

[TwIzTeD_3kGt]

Used my Solus Pro, same thing.

P2 is bits 12-15 off, the rest enabled.

Nevermind its back on.

[TwIzTeD_3kGt]

I disabled knock on CEL and it's stayed off so far. Why now when I had no problems with it before?

[Greg E]

It's a coincidence.

[TwIzTeD_3kGt]

It's a coincidence.

Indeed it is, its on right now. What to do? If my Solus Pro can't read the code stored, what will?

[Jimvr4]

Codes can be read manually. Count number of slow flashes and number of fast flashes. Slow count = tens digit and fast count = ones digit.

[Greg E]

Indeed it is, its on right now. What to do? If my Solus Pro can't read the code stored, what will?

Is your stock boost control solenoid still plugged in?

If not, disable it in periphery 3.

[FluffyCow]

That might be why my CEL is on as I have no way of reading CELs other than evoscan.

[TwIzTeD_3kGt]

Is your stock boost control solenoid still plugged in?

If not, disable it in periphery 3.

Hmm I'll check, I remember seeing it plugged in and thinking there was no reason to have it plugged in, just can't remember if I left it plugged in or not.

I just discovered this is the same problem I had when I first installed the ECU. If I turn the key to on, then start the engine, I'll have a CEL. If I turn it off and turn it back on within, say, 5 seconds, the CEL is gone. Originally this problem went away after I disabled bits 13-15 in periphery 2, but now the problem is back. The bits are still disabled. I wonder if another one needs to be disabled? Like a monitor that the ECU would test last, since my daily commute is so short my monitors can take weeks to run...

First things first, check the BCS.

[TwIzTeD_3kGt]

Bcs is plugged in. Its just weird that if I cycle the key on/off/on there's no light. Almost like the bulb check is getting stuck on.

[Greg E]

Disable all the periphery tests in 2 thru 4 (leave periphery 0 alone). That will disable all the DTC checks. Clear the CEL, drive a while report back.

If it stays off, you have a bad sensor. If it comes back on, my curiosity is peaked. I had an old old beta ROM that would do this but I fixed it for the final release. Wonder if you somehow got your hands on that beta ROM.

[TwIzTeD_3kGt]

Disable all the periphery tests in 2 thru 4 (leave periphery 0 alone). That will disable all the DTC checks. Clear the CEL, drive a while report back.

If it stays off, you have a bad sensor. If it comes back on, my curiosity is peaked. I had an old old beta ROM that would do this but I fixed it for the final release. Wonder if you somehow got your hands on that beta ROM.

Will do.

[TwIzTeD_3kGt]

Disable all the periphery tests in 2 thru 4 (leave periphery 0 alone). That will disable all the DTC checks. Clear the CEL, drive a while report back.

If it stays off, you have a bad sensor. If it comes back on, my curiosity is peaked. I had an old old beta ROM that would do this but I fixed it for the final release. Wonder if you somehow got your hands on that beta ROM.

Been a few days with those periphery tests disabled, the CEL hasn't come back so it must be a sensor error. Only problem is, how will I figure out which one without the code? Is there a better way than 1 by 1 enabling those peripheries?

[Greg E]

The 99 manual goes thru a couple ways to pull the CEL codes manually. After you get the code, there is a list of all of them in the same section.

This section helped me map the peripheries out. :)

[twinspoolin94]

This just started happening out of the blue. Hadn't flashed anything for a couple days, then yesterday afternoon I start it and the CEL is on. I used a scan tool to check the code, no DTC's found. I cleared it, it was gone on the next start up. The next start up, it was back again, no DTC's found again. I drove it, drove it hard, CEL went out. Next startup it's back on.

Any ideas?

I Have the exact same problem. Just got my flash up and running.

[striker2]

I now have this problem as well. Its been fine for several months and now after installing the 450cc injectors and flashing for them it started this. i also cant connect my scan tool to even check for codes (it wont even turn on when plugged in) but haven't tried the tactrix yet. Has anyone figured out what was causing this?

[Greg E]

The 99 manual goes thru a couple ways to pull the CEL codes manually. After you get the code, there is a list of all of them in the same section.

This section helped me map the peripheries out. :)

Got missed the first time...

[striker2]

I feel dumb. Turns out my scan tool took a shit. Hooked it up at work and it read codes just fine. :facepalm:

[NOMIEZVR4]

So I've go the same issue as OP, but here is whats been happening with mine ever since I started using v2.

On 1st start the CEL will just stay on from the moment the key is put to the on position. Light never goes off. However, if I cycle the key back off and then back on, the light disappears and doesn't turn on while driving. Only if i turn the car off and leave it off for a few hrs when i turn the key to the on position to start it, the CEL illuminates and stays on. I checked the code once, it was p0300 but it threw it even before the car was started..LOL

[NOMIEZVR4]

Also, KNOCK CEL is enabled but it doesn't light up if/when the car knocks...?? Its set for 5 counts..

EDIT: I'm reading thru the thread again this time, not in a rush...I'll try what the OP did and report back...

[Greg E]

Unplug your ECUs for 10-20 min to reset the RAM. Sometimes people forget to disable CELs in the peripheries and a code is tripped. They then disable the periphery and reflash.

This makes the code ignore that flag entirely. Disabling a periphery will not clear the code. You have to reset the ECU to clear it.