Another flashing "O/D Off" question

[98ExplorerGuy]

1998 Explorer with "E" engine (4.0L, 6 cyl) and 206,000 miles on original transmission.

I drive 23 miles each way to and from work 5 days per week, 21+ miles are highway at typical 60 - 70 mph.

Yesterday morning I stopped at Dunkin' about 18 miles into my drive. As I was pulling back onto the highway I noticed the O/D Off indicator was flashing. Played with the button and couldn't get it to go off. It remained on the rest of the drive; I arrived at work, killed the engine and restarted - the light continued to flash.

At the end of the workday I started the car and the light was now off however it began flashing again about 5 miles into the drive home. Same thing this morning - light off but came on several miles into the drive.

I borrowed a coworker's ODBII device and the only codes were P0430, P0171 and P0174 - all of which I already knew about. Surprised there weren't any codes specific to the O/D issue. I cleared all codes and the O/D indicator turned off.

So, any thoughts on this issue? I can tell you that overdrive is definitely kicking in; is this likely to be the "slipping torque converter" problem?

Any thoughts on probable repair costs? I am hoping to get another year out of this vehicle...

 

[drdoom]

To be sure, get hooked up to a pro-level scanner that can read Ford transmission codes. But as you to suspect, you are likely looking at a P0741. Around here the repair cost usually exceeds the value of the truck, around $3800.

 

[drdoom]

Sounds like you have some problems with EVAP and or vacuum leaks.

 

[98ExplorerGuy]

Sounds like you have some problems with EVAP and or vacuum leaks.

Yeah, I know about the (probable) vacuum leak. I presume that is a separate issue, unrelated to the new flashing O/D Off problem.

I just went out to lunch and drove about four miles maxing out at maybe 35-40 mph; the light stayed off the entire time. I am guessing it will come back on during the drive home this evening.

FWIW, the tranny appears to be functioning normally in all respects. It shifts smoothly and overdrive is kicking in as expected. I tested this morning while driving at about 65 mph / 2,250 rpm - I pushed the O/D button thereby turning it off and the rpm's jumped to 3,000; pushed O/D button again and a few seconds later the rpm's dropped back to 2,250.

 

[drdoom]

OK, if that is your normal cruising RPM, then you have lockup. And it also sounds like it is not in"limp home" mode. You would notice that, the pressure rise and resultant hard shifting. Get thhe codes, and post back up, we'll take it from there.

 

[98ExplorerGuy]

OK, if that is your normal cruising RPM, then you have lockup. And it also sounds like it is not in"limp home" mode. You would notice that, the pressure rise and resultant hard shifting. Get thhe codes, and post back up, we'll take it from there.

I'll try to do that; it may take a few days.

 

[1992fordgreen]

over 200k on the original tranny, you might as well rebuild it and the TC.