I have a 1999 Dodge Ram Quad Cab 4 x 4 with a 5.9L. When I am cruising at speed the RMP surges 300-500 RPMs for no apart reason. This surge occures with the cruise control engaged and when I am driving normally. The truck accelerates and idles with no issues. I had the rear diff speed sensor changed by a licensed mechanic about 2 months ago, but the RPM surge just started this week. Does anyone have an idea what I can check to fix this?

Thanks

 

99% chance that your Throttle Position Sensor is bad. You can get one at most parts stores for roughly $35. You can change it yourself in 5-10 minutes.

 

Thanks for the reply.

If it is the throttle position sensor would it show up as a code? No codes are registering. Thanks again

 

no it wont. the sensor starts getting noisey and the pcm thinks it needs to un-lock the torque converter so thats what it does. I have never heard of any of these failures throwing a code.

 

To add to what Steve said - I had the surge problem almost from the day I got my truck new. I had the dealer check the tranny out several times because I just knew something wasn't right. The dealer techs could never find the problem., even after rebuilding my tranny twice under warranty after it burnt up. I found out about the TPS on here - and it fixed the problem. I let the dealer know what the problem was - they had no clue because their computer diagnostics didn't tell them.....
I firmly believe that the bad tps on mine is what caused my tranny to burn up twice - due to excessive shifting and converter lock/unlocking

 

Can someone help here.... I just received Code 1763 on the way home. I searched for it but can not seem to find out what the issue is or where to start? Can anyone help? I just had the throttle body cleaned, new plugs and wires done on the truck last week. Any ideas. The truck is starting to lunge and surge. Thank you.

 

code 1763 does not exist in the list I have, maybe someone else can chime in.

Racin, do you remember the thread about the wiring issue that was causing a similar problem that was in the tranny? I've been looking for that thread and cant seem to find it. did you ever see it (and save the link)?

 

OBDII Code P1763 - Governor Pressure Sensor Volts Too High (Chrysler, Jeep)

Now ... what's THAT mean?

 

Yeah, Steve. I will find it in the next 24 hours or so and pm it to ya......It's on my home 'puter - I'm on the work 'puter now.....

 

it means a the sensor in the tranny has gone bad... take it to a tranny shop and have them swap it out and do a servicing on it. there is another sensor in there that also goes bad, i'd have them swap that one out while they are in there. I had a tranny problem that related to that sensor, never thru a code and it turned out to be one of the 2 sensors inthe tranny. fixed it and never had a problem again.