CEL Coming on and Turning Off

[Movin]

I guess you are no stranger to figuring things out!! That was quick, all the way through to fixed, awesome!

[Prafeston]

Well I was able to check the test connector and count the flashes. I drove till the CEL turned on and then pulled over and turned the car off. After grounding the STI and turning the key to ON I was getting two codes: 2 long 4 short. and 2 long 6 short. Couldn't find the dang codes in my Ford Service manual to figure out what these were..

[RhodeStiva]

CEL Coming on and Turning Off

Does it come on in like 5 minutes of driving it every time ? If so I bet it's the o2 sensor.

[Prafeston]

I have to be traveling at a constant speed over 50mph for 5-10 minutes probably before it will come on. Could drive it around town all day under 45 and never have it come on.

[RhodeStiva]

yea i have the same problem right haven't yet changed to o2 sensor but i am pretty sure that is the issue.

[TorqueEffect]

Well I was able to check the test connector and count the flashes. I drove till the CEL turned on and then pulled over and turned the car off. After grounding the STI and turning the key to ON I was getting two codes: 2 long 4 short. and 2 long 6 short. Couldn't find the dang codes in my Ford Service manual to figure out what these were..

Code 24 doesn't exist, but for code 26 it says the Solenoid valve (purge control) at least that is what's in the Haynes manual.

The 89' Shop Manual also doesn't list a code 24, but again, Code 26 says Canister Purge Solenoid, and yes that is listed for EFI engine.

[micro_trucktiva]

Yes, the black connector not the white one. Looking at the codes (9 total) for my '93 EFI, some are KOEO (a Ford term used to describe Key On Engine Off) some are KOER (another a Ford term used to describe Key On Engine Running) some are both. Code 15 & Code 17 O2 LOW or DOES NOT CHANGE = KOER. Once the key is turned off the ECA will forget the code until the condition occurs again, running, not stored in Non-Volitile memory.

You are driving down the road ... MIL comes on ... keep driving or pull over either way ... light goes out ... drive on .... light comes back on ... goes out again. Shut the engine off ... ground the black connector ... NO CODES. Why? Did the car fix itself? NO - Where is the code? gone. When you were driving the o2 sensor saw either a lean condition or a rich condition and did not switch as expected by the ECA algorithm. When you let off the accelerator the o2 started switching again so the light was turned off by the ECA because the fault no longer exsists. The code either 15 or 17 is still in Volitile Memory (RAM) and will be cleared when the key is turned off. You can pull this code only before the key is turned off. This is where we get the mystery "flashing CEL while driving". Not to be confused with OBDII Misfire Monitor reporting a Type "A" Misfire. We don't have OBDII on Festiva. We have OBDI. So as the "lack of o2 switch" comes on at steady speed and goes away because you let it idle. At idle the o2 switches, no problem, no light needed. This is a signal from the ECA that you are not going to get as good of mileage as you could be getting if you were to correct the condition. By the way Fords do not have a CEL (Check Engine Light) they all have an MIL (Malfunction Indicator Lamp) minor difference as mandated by CARB (California Air Resource Board).

Exactly what my festiva is doing. If I idle(like at a light) no cel but once I give it gas boom it flashes every few minutes.

Can someone get a picture of the test connector? And which one to ground.... thanks

[Pu241]

Can someone get a picture of the test connector? And which one to ground.... thanks

No pics, not going out in cold and dark.

This:
Ground the single black connector and check your codes! -Movin

Not this:
Single plug. Yellow w/ green line. - Prafeston

[micro_trucktiva]

No pics, not going out in cold and dark.

This:
Ground the single black connector and check your codes! -Movin

Not this:
Single plug. Yellow w/ green line. - Prafeston

Lol I didn't mean right now lol when it's light outside

[BLACKESTSHEEP]

how do you disconnect the CEL...?..thanks

[nitrofarm]

how do you disconnect the CEL...?..thanks

Remove the Dash Bulb

[BLACKESTSHEEP]

hi nitrofarm, thank you for answering my question...i'm new to the site, so i dont want to bother you again with a dumb question, but i'm assuming the dash bulb is behind the instrument panel, which is black and plastic on my 89 ford festiva..i dont have any idea how to get in there...i will look thru the forum to find out how to get to the Dash Bulb, but if you know how to get to the dash bulb in an easy way, or a forum thread that may help me, i'd appreciate it..either way, thank for your help..
i have had the 'check engine light' come on now for maybe 10 years off and on for me, i never knew why..it would go off, and i would forget about it lol...i have read on this forum, and just learned, that i can read the code via the female single connector in the ride side of the engine compartment, with a jumper wire, or a paperclip etc..the CEL will flash and read out a code..however, FYI, a 'check engine light' will be an instant fail of a smog inspection, so if i don't get a fix for the problem, i want to still pass my smog check coming up soon, at least till i figure out what the problem is..i want to try to fix the problem myself at home..this forum has alot of info i never knew existed ! so thanks again !! ty1

[nitrofarm]

Well thats a problem because if the inspector does the test correctly he will know the bulb is burned out. You'll notice that when the engine is "OFF" but the key is in the "RUN" position. All of your warning bulbs come on,this is how you know if you have a bad bulb. And this is how the inspectors are supposed to perform their test.

[BLACKESTSHEEP]

hi nitrofarm.....thanks for the info..and your absolutely right, i forgot all about that... a proper inspection checks for all the functioning dash lights a as well...if you disconnected your 'check engine light' bulb, i don't know how you pass your smog, unless you replace it just prior to the test..but either way..thanks again...luckily, for me, my check engine light come on intermittently, and like a previous poster mentioned..usually it occurs after a longer freeway drive in the 60's mph for 30 minutes or so.....and will pop on till the next day or so,, then go off if I'm city driving..probably the o2 sensor, from what i have read in the forum..my next repair will be to check the CEL or the MIL..and see if i can fix it myself...:happy3::happy3: thanks for your reply..)

[nitrofarm]

The 02 sensors are really easy to do on these little cars. Just a thought