ok i just bought a 95 2500 cummins auto, i bought this truck two weeks ago and the truck work fine when i drove it home, park it for a week. now i got in it today and was driving to work and it doesn't shift to OD but it shifts fine threw the rest of the gears.. any one have any ideas on what to check , thanks for anyhelp

 

OTC........first, Welcome To The Forum.

Be a little patient, the site is kinda screwy right now and some folks cant post at all.

One of the guys that is a bit more familiar with your setup will be along shortly.

 

isn't there something about the battery cables or a tranny ground that causes that issue?

 

thanks for the heads up cumminalong, and lilfroger do u have any more detail on the battery cable thing ??

 

just check to make sure they are all tight and not corroded

 

The battery cable corrosion and such is mostly for the 24V trucks, the APPS can give off a funky signal and cause the TQ-converter to lock/un-lock. This '95 is the old 47RH, OD lock should be based on speed and a throttle position sensor (nifty little $30-ish one instead of the more 'spensive APPS). I'd guess your sensor is in-op. Unless you have a speedo problem to boot, then you could have a bad speed sensor (it's mounted in the rear-end reading a tone-ring). Drew or parts/service may know more, though.

 

pics please

have you adjusted the trans yet?

the TPS (throttle position sensor) may be faulty. either remove it and clean it, or replace it.

also check all ground straps..battery, chasis, engine, trans, etc...

clean and make sure they are tight.

make sure TPS connection and mounting screws are tight.

 

ok so i cleand all the grounds, check all the conections, and still no overdrive, how do i check the tps sensor i know that there is a ground prong refeencevoltage and a signal prong, whats the max signal at full throtle an min at idle ?? and how do i check the temp sensor ??? and the truck is not throwing a check engine light does that mean the ecm is readingtrans temp ?? thanks for your help guys