Attention: TDR Forum Junkies • Truck is in what is called "lock-up" mode on 24 valve engines. Sometimes it is called "limp" mode. * This means it does not shift into first when truck is stopped, and it does not shift into OD around 45-50mph like it normally does.
• When it is in this mode it is 100% of the time. *
• I have taken the truck to the dealer and they replaced the PCM. The wiring to the temperature sensor was spliced and grounded incorrectly*which is what the dealer believed was*what caused the*PCM to fail* It solved the problem for about a block. * They decided to replace trans governor pressure sensor, transducer solenoid,*overdrive solenoid, and all seals relating thereto. This solved the problem for about a month. * The truck*started to act up again intermittantly for about a day and then it was*100% of the time again. *
• The Truck was returned and the problem could not be duplicated. * The dealer replaced a recalled Throttle linkage arm. * The truck ran fine for about another month.
• The last time it was taken into the dealer, they could not duplicate the problem again. The truck sat for about a day. * They did a more extensive diagnosis to determine weather the solenoids they replaced were functioning properly. * The electrical output on operation of solenoids was correct. * However there were many splices seen under dash area. There were two codes that came up:
• Coolant temp
• Fuel Sinding unit
• The transmission does not respond to shifting into 1 on the shifter. * The Lowest gear I can get is 2nd, and that is only if I drop the shifter into 2.
• I drive at about 50-60mph with the rpm at about 2500, shift into neutral, shut the truck off completely, restart resting my foot on the gas pedal with no more pressure than my foot weight and the rpms rev to about 1100-1500rpm. * If I do this and then shift into D all while rolling at about 50mph the truck will then shift into OD. * However as soon as I stop the truck goes back into the lockup mode.
12 valve, 1998 2500 4X4. Mystery switch was removed (lockup).
Help?
• When it is in this mode it is 100% of the time. *
• I have taken the truck to the dealer and they replaced the PCM. The wiring to the temperature sensor was spliced and grounded incorrectly*which is what the dealer believed was*what caused the*PCM to fail* It solved the problem for about a block. * They decided to replace trans governor pressure sensor, transducer solenoid,*overdrive solenoid, and all seals relating thereto. This solved the problem for about a month. * The truck*started to act up again intermittantly for about a day and then it was*100% of the time again. *
• The Truck was returned and the problem could not be duplicated. * The dealer replaced a recalled Throttle linkage arm. * The truck ran fine for about another month.
• The last time it was taken into the dealer, they could not duplicate the problem again. The truck sat for about a day. * They did a more extensive diagnosis to determine weather the solenoids they replaced were functioning properly. * The electrical output on operation of solenoids was correct. * However there were many splices seen under dash area. There were two codes that came up:
• Coolant temp
• Fuel Sinding unit
• The transmission does not respond to shifting into 1 on the shifter. * The Lowest gear I can get is 2nd, and that is only if I drop the shifter into 2.
• I drive at about 50-60mph with the rpm at about 2500, shift into neutral, shut the truck off completely, restart resting my foot on the gas pedal with no more pressure than my foot weight and the rpms rev to about 1100-1500rpm. * If I do this and then shift into D all while rolling at about 50mph the truck will then shift into OD. * However as soon as I stop the truck goes back into the lockup mode.
12 valve, 1998 2500 4X4. Mystery switch was removed (lockup).
Help?
