Truck is a 95 Auto.

Have been chasing a cruise control problem for over a week. I have ordered the diagnostic manual from dailmerchyrsler but it has not made it here. Never received a confirmation email either so I guess I better call.

The cruise works intermittently. Mostly it will work after the truck has been started and will not work again until a re-start. I have worked on this some as well as a local shop. The have extensively checked for vacum problems and there are none. The PCM threw a servo code for them once so we replaced the servo with a new one. The computer is seeing the brakelight switch and the switches on the steering wheel, but I've replaced both of those just in case. I suspect there will be plenty more diagnostic work once I receive the manual, but worst case scenario I guess would be a bad pcm.

For those that have replaced a PCM, if you get the right one either from a dealer or rebuilt is is just a straight bolt on or is there programming required?

It would have been great to get this fixed over the last week, since I have to drive to southwest Wyoming to start a new job Tuesday but I've run out of time and ideas.

PS I'll have a 95 cruise servo a 97 cruise servo and some 95 cruise switches for sale soon!!

 

No matter where you get the pcm it will have to programed for your truck.
I've replaced PCMs on two trucks, a '95 and '97 to fix the cruise, both times it wasn't the problem. In fact my friend in Montana would probably sell his extra for sure good already programed '95 pcm. Let me know.
Best thing you can do is swap PCMs with a truck that is working right to see if it is indeed the problem.

In the cases where the problem wasn't solved by a new PCM-
the problem on one was enlarged female connectors from voltmeter probes, the other had one pin bent over on the brake light switch. The bent pin was hard to spot, no way to see it without a mirror. Apparently the dealer bent the pin while the truck was under warranty.

 

Infidel I found your post on the bent pin on the brake light switch checked that and all looked well, however I guess I might not have checked what you found. I pulled the knee bolester removed the brakelight switch from the bracket and checked pins on the switch and the connector. Didn't need a mirror to check what I checked, does that sound right?

I've had this truck for 25,000 miles and I know during that time the PCM was not poked, prodded or otherwise molested. It may well have enlarged female connections and if we do check anything else to it on Monday that will probably be it.

Hopefully I will get the diagnostics manual on Monday before I head out. What part of Montana are you (and the new PCM) in? I have to be in Lander, Wyoming for about a week prior to going to the southwest corner. I don't think there is another truck around here to switch with for a check.

Thanks

 

You have a PM