hey all I was just wondering if anybody heard of a shift computer that supposedly controls the transmission under your passenger seat? I have a 98 Dodge 2500 having shift problems of don't want to shift in overdrive but I could shift manually from first to second but nothing from 2nd to 3rd.seems in limp mode, but not setting any codes. Speedo is going bonkers too, Have replaced the output speed sensor on tranny but didn't. Fix. Last year put new sensor on diff,culd it be bad again?

 

Welcome to DF
No there no control under the passenger seat that controls the transmission. The Powertrain Controller controls the transmission for overdrive. Do you have a 5.9L gas engine, 8.0 V10 or a 5.9 diesel engine in your 2500 truck. Next question, do you have a speed sensor on the transmission? That is not the same as a output speed sensor. Also rear sensor on the differential is for the ABS, is the ABS lamp on? Because if it is the tone wheel on the carrier could be missing or bent tooth. If the transmission isn't shifting when you move the lever to drive, Then I would say the problem is in the valve body. When was the last time the transmission was serviced?

 

Master it is a 5.9 gas. The abs and check eng light are both on. Parts store said output speed sensor. Tranny fluid came out when i replaced it just under shift linkage it screws in. Its a rebuild about 72000 miles on it.

 

Output speed sensor is on the rear of the trans, you replaced the park/neutral safety switch.

 

It was on the rear drivers side not one by linkage. My badd. So any thoughts.

 

It is entirely possible that the sensor on the diff is bad again.

 

Did you pull the codes from the ABS module? Can you post the codes.

 

Only code i got is oxygen sensor. No other codes. Im stumped.

 

Probably have to go to a shop to get ABS codes. Most parts store scanners won't read 'em.

 

Well put a new abs sensor on diff, nothing..grrr.. speedo is deadand no shift, now seems it's. Slipping too from 1st to 2nd, still no third. Guess pull the pan this weekend, and replace. The solenoid s. Any body got the link for the write up? Thnks guys.