Topic: manual swap- torque coverter lock up

[jeepheap1492]

Swapped my auto to a manual, and now i have a check engine light for the torque converter lock up and idle dosent drop till im fully stopped. Is there any way to bypass this with a switch or a resistor? My tags arent up for renewal anytime soon, but obviously this will be a problem when i go and i really dont want to buy a new ECM. Anybody done this or have any ideas?

[sharpxmen]

my idle doesn't drop either until i'm stopped (I have YJ with a manual). Can't help much with the auto, just couple of ideas: maybe it's a sensor that it needs, as far as i know the lockup solenoid should go thru a relay (do you still have it or was it removed, if you removed it put it back and see if that helps).

[jagular7]

The CEL is showing a run fault and this has consequences in the program running your jeep. To fix, you'll require a re-program of the computer or a computer of the same model/year of your with the 5-speed as the trans.

I recently saw somewhere, can't remember, where an aftermarket company is now providing stand alone wire harness for the 4.0l engine. I'm thinking it was this year's SEMA. They may have something similar for the 4bngr.

[sharpxmen]

if that is the case (what he ^ said) you could probably exchange your PCM with one from a manual and be done with it (same year/engine), not sure if the VIN is written in it or not.

[jfrabat]

if that is the case (what he ^ said) you could probably exchange your PCM with one from a manual and be done with it (same year/engine), not sure if the VIN is written in it or not.

VIN is NOT written in the PCM...  I have two of them and they both work, and they are not even the same part number!  One has some heat sinks inside the ECU, and the other does not (as far as I can tell, that's the only difference).

[sharpxmen]

VIN is NOT written in the PCM...  I have two of them and they both work, and they are not even the same part number!  One has some heat sinks inside the ECU, and the other does not (as far as I can tell, that's the only difference).

i think he has a TJ, as in OBD2 has to be clean of codes to pass inspection (as far as i know they don't do that on obd1 and i can't see why the YJ auto would throw a code on the auto to manual swap. Second, on some newer vehicles I think the vin is written to the PCM, now i don't know if his is but it might invalidate the inspection if it doesn't match (but then again i don't know for sure, i'm just warning him).

it will work regardless, the vin itself has nothing to do with the way it runs as long as it matches the year/model.

[jeepheap1492]

Yes, my jeep is an 01. I actually read on another forum that you can basically fool the computer by putting a resistor in place of the solinoid. I threw a 10 watt 50 ohm resistor in and the code has cleared.

[sharpxmen]

Yes, my jeep is an 01. I actually read on another forum that you can basically fool the computer by putting a resistor in place of the solinoid. I threw a 10 watt 50 ohm resistor in and the code has cleared.

i guess it's directly driven then (no relay, I think YJs had a relay for the lockup). Good to know.

[dwtaylorpdx]

When I was looking for a new ECm for fidlling with, all the guys that sold them told me the manual and auto use different boxes, and the main item was the trans sensor for the lockup that would screw things up, on the other hand Xj ECU are the  same with less heat sinks.. :)

[grumpygy]

Just wonder if the dealer could flash the unit to reconfigure it.

[dwtaylorpdx]

I have found in general the Jeep dealers are not interested in touching a non standard jeep.
Heck most of them don't even have a tech who knows how to work with their ECU. They
would rather swap parts at your cost to "fix" the problem.

Heck it took me an hour to convince them to hook the diag box up to my OBD1 YJ
because I had oversize tires and a lift kit. The bone heads wanted me to put the stock equipment
back on to fix it..

Jeep is the lamest dealer net ever.

[sharpxmen]

When I was looking for a new ECm for fidlling with, all the guys that sold them told me the manual and auto use different boxes, and the main item was the trans sensor for the lockup that would screw things up, on the other hand Xj ECU are the  same with less heat sinks.. :)

the XJ PCM puts out 6 or 7 more HP, dunno if the rest is the same but i can't see why not. I thinkthe YJ was lighter and it fell in a different emissions category, only explanation i could come up with for the difference in output between the 2 of them.

[dwtaylorpdx]

Yea,, good question.. My best silly guess is the exhaust is shorter, so if they wind up the power much it fails emissions? I know I blew up 3 cats in the first couple years.. Put a random tech on and no more problems and passed emissions with flying colors..

The XJ looks like its a longer intake system too, the pipe from teh air filter box to the throttle body looks longer than the YJ..

We may never know...

[sharpxmen]

i know on my emissions test is written the category (vehicle weight category level of emissions: max CO2, carbon monoxide and NOx - something like that)

XJ
HP 130
Torque 149 lbft

YJ
HP 123
Torque 139 lbft