Engine/Transmission (1998.5 - 2002) Rpid Downshifting

[pharlacher]

I am on the road with my 1999 2500 auto 4X4 3. 54 rear and 130,000 miles. I have a Comp edge, RV injectors, four inch exhaust, TAB, BD exhaust, BD low stall torque convertor, BD Valve Body and shift controller and a FASS. I have been on the road for about 26,000 miles and have had very little trouble. I stopped at BD on the way to alaska and they dynoed my truck. 341 HP and 911 FTLBS of Torque.



I have a problem with the transmission downshifting for a second. The engine rpm goes up about 100 for a second. I do not have a TPS so I can't clean or replace it. My Tech manual said it was replaced with a manual cable and linkage. I cleaned and lubricated the manual linkage. I cleaned the connection on the Speed sensor switch on the rear of the tranmission. Do I need to replace it?



Can anyone help me out? Still driving the truck and still on the road.



Also, I have been hearing about a relay in the FASS wirering. Do I need one? What does it do. If I need one where can I get one?



Thanks, Paul

 

[AKAMAC]

Does the down shift occur in all shift phases? Looks like you have the dreaded T/C lock unlock if it is only in 3rd/OD shift pattern. Call BD they will let you know.



The FASS system draws more current than the stock LP. The relay takes the load off the PCM and allows the load to draw off the batteries. Call your supplier.

 

[pharlacher]

Thanks Mac. It does only happen in 3rd and OD. I will call BD. I will also call Diesel Performance on the FASS. Will the extra current pull harm the PCM?



Paul

 

[AKAMAC]

The only problem would be with the minimal specifications that Dodge uses for wire size and the load the ECM/PCM will handle. It's one of those better safe than sorry lines. Hope the resistor they sell you for the transmission is cheap.

 

[pharlacher]

Thanks again Mac. I am still on the road so I can only get to a computer when we find a local library.



The problem with my truck was a bad TPS. Put a new one on and it is running great. BD suggested I get the latest reflash. I was up to date.



I ordered a new wiring harness with the resistor in it. Better safe than sorry.