I will dry to make this as brief as possible.

I have a 2000 Excursion, 4WD, v10, with 115000 miles.

After some very heavy rains this past January and February ( rare for southern California), I went out to start it and it felt and sounded like it was running on 5 cylinders, and the check engine light was on ("Service Engine Soon" light). I let it run for a bit hoping it would clear itself out.

I limped it over to the closest Ford to to have them check it out. I told them I thought it might be plugs or coils. They are 23 years old.

They checked it out and called me to say they thought the main problem was the PCM. One whole bank of coils weren't getting signal. After they replaced that, they then said it was running much better but it did look like it could use the plugs and coils. So they replaced them too. When I went to pick it up, low and behold the check engine light was on. I thought maybe it just had to be run a while and driving it home might clear it all out. No. Light stayed on. I disconnected the battery to clear any codes, but didn't solver it.

Searching on the web I kept running across O2 Sensor suggestions. So I replaced both sensors before the converter. It was not an original California vehicle so it didn't have the 2 behind the converter. That seemed to fix the light issue for about 4 days, and the light came back on. I called the tech that worked on it and he came over with his computer and he said he had never seen the code that came up. Said it was some kind of grounding issue. He was going to call Ford and see what it meant. They told him to look into the relay that that connects to the PCM might be causing it. Well, they replaced that and the light was out. He drove it for a few miles and all seemed good. Until the next morning when he started it up and the light was back on. Now he wants to replaces the ignition switch?

Can anybody here guide me as to what might be wrong? What to look for? This whole process as been going on since March 3. Over six months. HELP!!

Sorry this long. I wanted to give you all the info to help find a solution.

Thank you all.

Charlie

 

You mention issues after heavy rain. The 2000 excursions have the GEM module behind the fuse box there under the steering wheel. If your windshield is leaking water can get down there from the A pillar and into the GEM module and cause all kinds of issues. Ask me how I know. So before throwing parts and more money at it check for leaks.

 

Without knowing what codes are present nobody will be able to fix this.

 

Thanks for the replies.

The code we are getting is P1630.

Is the GEM the same as the PCM? We did replace that along with plugs and coils.

Thanks

 

e11even,

Thanks for the reply.

Is the GEM the same as the PCM? We did change that already.

And yes, I did (still might) have a windshield leak. As soon as we solve the engine light issue I plan to attack that.

The code we got was P1630. Any ideas?

Thanks again.

 

Mark,

The code we got was P1630.

Any ideas?

Thanks

 

Go re-check your fault code(s). DTC P1630 was not used on a truck that old.

 

The GEM is the Generic Electronic Module. The PCM is the Powertrain Control Module. Two separate modules.

 

Not really related, but you should never tell a service center what you think is wrong with the car. If you're wrong, you can bet they will do the thing anyway and charge you for it. Maybe your plugs were bad and needed replacing at that miles but you'll never know now and putting plugs in it didn't fix the problem so they got your money for mostly nothing. Again, clarify your trouble codes and report back.

The dealership you're working with doesn't seem to have a good handle on how to troubleshoot your truck which is pretty sad considering its not remotely exotic and that powertrain was sold into 20 trillion vehicles. They keep swinging and missing.

 

Does the GEM module have to be programmed like the PCM? I see some refirbished they say pre-programmed. Would that be a plug and play or does it need further programming?

 

Does the GEM module have to be programmed like the PCM? I see some refirbished they say pre-programmed. Would that be a plug and play or does it need further programming?