Engine/Transmission (1998.5 - 2002) TC Lock Unlock Issues

[DWest]

My TC has been doing the lock unlock for sometime now and unhooking the negative post has made it go away for up to two weeks after a 12 hr disconnect. Now it has to be for at least 24 hrs and only last a few hrs. Dave Goerend installed the noise filter and the tin foil wrap to no avail. It was much worse when his scan tool was on the truck. Now when the exhaust brake comes on the light in the controler box just flashes so the TC doesn't stay locked up. Does this sound like the PCM is going seeing as it is sensitive to the scan tool? I have used my truck a number of times to jumpstart equipment and was told this could have damaged the PCM. The APPS is also talked about for this issue but few that have replaced it have had success. Any help please! DW

 

[Graphic man]

another guy had the same issue, he spent about 2 hrs and cleaned every ground he could find and it fixed it.



give that a try and keep us posted



Scott

 

[FourBarR]

Been there ,cleaning all repeat all the grounds cured my truck or over a year. It came back and I install a dtt noise filter it was ok for several months,then started again. found a service bulltin and took the truck to d/c and had it reflashed. everything ok for a while. it came back and I scaned it and got codes 121,120 which is apps. replaced apps 730. 00 in canada. has not returned in 2 years. long story but think it is now solved . have you scaned for codes yet? hope this helps.

 

[SnoKing]

Been there ,cleaning all repeat all the grounds cured my truck or over a year. It came back and I install a dtt noise filter it was ok for several months,then started again. found a service bulltin and took the truck to d/c and had it reflashed. everything ok for a while. it came back and I scaned it and got codes 121,120 which is apps. replaced apps 730. 00 in canada. has not returned in 2 years. long story but think it is now solved . have you scaned for codes yet? hope this helps.

Well on our recent 4200 mile RV trip, I think I firgured out that the cell phone charger or cell phone it self is screwing with my lock up. I had the problem off and on for the last two years, that I would come out of lockup once in a while. During the 38 day trip with the 5er, I only had a problem on one day, and both my DW and my cell phones were setting on the cup holder directly above the smart controller and mine was on the charger. We were in a remote area north of Baker City, Or and maybe the thri-mode phones were in analog mode. The TC would not stay locked going down a small hill.



I moved the phones and did not have another problem. Going to DTT for normal service Wednesday and am going to relate the issue to Bill. FYI, I have the filter and foil on the alternator lead.



Bill had me install a lock up switch last year to help isolate the issue, and it would not resolve the lock up issue. I think maybe the smart controller is dropping the +12V when I see the issue. More after I talk to Bill. SNOKING

 

[KTobin]

Mine was doing that for a long time. The tinfoil thing didn't work. I spent a couple hours cleanning all grounds until all mating surfaces were shinny. I slipped small lock washers between ground lugs and ground, and smeared them relentlessly with dialectric grease. Pay special attention to the lousy ground connection between the PCM and firewall. It instantly cured my problem and it's been fine for a year now. I don't know if it was one or many grounds that were bad and I don't care. You're only as good as your weakest link. Do them all. It's cheep.



Kevin