96 Taurus check eng lt inop.

[SteveG3]

I had to go to the Emissions Test Center yesterday for my 96 Taurus wagon. I did not pass because the check engine light does not go on when you turn the key on prior to starting. I know it used to work as it has come on in the past when there was a problem. Do you think just a bulb needs to be changed? Is the bulb accessable? Can I get at it myself? Has this happened to anyone else?
Thanks

[SteveG3]

Well I got the instrument panel apart and replaced the bulb. It did not solve the problem. Engine service light still does not work.
The factory manual states the service engine light is controlled by the powertrain control module (PCM). At the moment I do not know where this PCM is located. The PCM may be bad, I guess, but the car runs good.
I may have to take it to the dealership

[shorod]

If you're able to have the computer scanned and it doesn't indicate that there are issues, then the PCM is not likely to be the problem. Since the car starts and runs, I also don't expect that the problem is the PCM. More likely is a wiring issue between the PCM and the bulb. There have been some issues with the flex board and connection for the instrument cluster, I'd suspect that's the issue.

-Rod

[SteveG3]

Well I went to two Ford dealerships so far. Both said "never heard of such a thing". And " I have no way of finding out what is a likely cause". I find that very funny. This is 2009 not 1969. The computer age, and they have no way to access Ford's massive records to see what it may be. Unreal.

[shorod]

It looks like you need to check pin 2 at the PCM connector or pin 15 of connector C250 at the instrument cluster (Pink/Light Green wire) to see if it has a ground when the bulb test should occur.

Do any of the other bulbs in the instrument cluster work for the bulb test or otherwise? The CEL, low fuel indicator, temp gauge power, fuel gauge power, tachometer power, door ajar indicator, seat belt indicator, oil pressure indicator and brake indicator all get power from the same supply, which is fused by a 5-amp fuse in the instrument panel fuse panel. If the other indicators and gauges work, you are looking at the Pink/Light Green wire from the PCM.

-Rod

[SteveG3]

Originally Posted by shorod

It looks like you need to check pin 2 at the PCM connector or pin 15 of connector C250 at the instrument cluster (Pink/Light Green wire) to see if it has a ground when the bulb test should occur.

Do any of the other bulbs in the instrument cluster work for the bulb test or otherwise? The CEL, low fuel indicator, temp gauge power, fuel gauge power, tachometer power, door ajar indicator, seat belt indicator, oil pressure indicator and brake indicator all get power from the same supply, which is fused by a 5-amp fuse in the instrument panel fuse panel. If the other indicators and gauges work, you are looking at the Pink/Light Green wire from the PCM.

-Rod

As a follow up (by the way all the other indicator lights did work) the place I did take it to did find, as you say a lost ground. Rather than finding its break, the mechanic ran a new wire as an alternate ground path and got it working. Thanks Rod. I was just frustrated. It appears I have the same issue for the horn and cruise as I replaced the clock spring. Now I can solve that one. At least now satisfy the emission test station.
Steve

[shorod]

Thank you for posting a follow-up!

-Rod