Engine/Transmission (1998.5 - 2002) Surging at 50-55 mph Trans slip?

[rootmanslim]

2001 2500 4x4 65,000 mi stock engine & transmission. 3. 54(?) (NOT 4. 10!) rear end. Rixon 19. 5 wheels. Operation at 7000+ ft up. After OD @ 50-55 mph shift engine will surge about 100-200 rpms and then settle back (towing or not). This will continue until you speed it up to 60 or slow it down to 40. It happens about every 5 -10 seconds. Turning off OD switch has no effect. Once the hammer is down and cruise set at 65-70 it never happens even hauling a 5500 lb horse trailer (loaded). Have 2 vol factory manual but can find no reference unless this is "flaring" and even that is not well explained. Local dealers are scary because anyone with any talent is working in gas fields not fixing MOPARS.

email is -- email address removed --

 

[FourBarR]

You probably have what is known as the torque converter lock and unlocking. there is lots of info here about and many people have expierenced this. The fixs are many,here are some of them

1- disconnect the negative teriminals on both batteries ,leave them off for 1 0r 2 hours. reconnect them ,turn on the ignition switch do not start the engine,slowly push the accelerator pedal to the floor,slowly let it up. this will reset the apps. Try this first.

2- Check for codes ignition on,off three times leave on dont start the engine,read codes in the odometer window. If there are codes write them down. post them here.

3- there is a brown /black wire from the alternator to ground on the right fender. wrap this wire in tin foil.

4- DTT has a filter that can be added to filter out the noise.

5- If you get codes 0121 or 0122 the apps may be bad, there is a procedure to readjust it but it requires some mechanical knowledge and the ability to use a multimeter. Hope this helps lot of info if you type in apps in the search . all the best with it.

 

[BTowler]

Suncoast has a fix here- http://www.suncoastconverters.com/images/APPS ground rewire.pdf



Try this if the ground fix doesn't work.

 

[John - K5AWO]

A code list that is easy to use is here: OBDII OBD2 Diagnostic Trouble Codes - P0200 - P0299

Some FAQs that might help are here: FAQ

Calibrating the APPS voltage is here: Dead Pedal-APPS/TPS adjustment - TDR Roundtable

hope this helps

 

[rootmanslim]

Fixed (I hope)

Folks, thanks for the advice. Today's project was installing a new lift pump and relocation kit so I now have 14. 5 psi at idle rather than 9. (Just in time as 2 of the 3 studs holding in the old lift pump had vibrated out of the pump, not the nuts the STUDS!) Real engines do shake as the dummy who decided to mount the lift pump on the engine might have considered!



After 3 hours and a nice fuel bath, I moved along to the surge issue.

I unhooked the neg terminals and let it sit for 2 hours. Then I did the gas pedal thing to reset the APPS. Then I did the code thing and got: P PCU. Then I wrapped the BLK/BRN wire in tinfoil and drove it about 30 miles with the cruise set at 50 and then 55. NO SURGING! Then I came home and did the code thing again. . NO CODES.

Maybe all 5 star dealers should get a roll of Western Family tinfoil!

Thanks again, Larry

Oo. Oo. Oo. Oo.