Cruise control not working

[Norwegian Bow-tie]

Hello! I have a 1996 K1500 6.5TD Chevrolet Suburban. My cruise control doesn't work anymore. It just died last week . All I know is that the fuse is OK and "playing" with the brakepedal hasn't fixed it. Where do I begin to look? I don't believe it's the multi - function - arm (or what you call it)either. Would it not have been an intermittent problem if that was the case?

[Basshopper]

I had the same problem and believe it or not John Kennedy told me to take off my FSD and tighten up the nuts on the back of the transitors and that fixed the problem, I paid $90 for a dealer to diagnose it they said put in a new computer. John was correct it fixed it. Something to try, good luck

[Norwegian Bow-tie]

Really?? How can that be the solution? Is grounding causing this problem?

[jjbouwens]

First thing that went wrong was the cruise control. My dealer tried everything and could not resolve the problem. Then the engine started stalling . A new remotely installed FSD was the answer to all these problems. The old one is still on the pump so if you try the trick with the screws please tell us the result.
1996 / RV / remote FSD Homemade heat sink / 73000 Km

[MTTwister]

My cruise would drop out randomly. Finally for the dealer to keep it for 4 days, I was out of town, and test the P.. out of it. Mechanic was hooking up the scanner going down the road with the cruise on, it dropped out on him - scared the S.. out of him, too. Got a new IP, but I'm betting the FSD was the culprit.

Search on FSD and PMD - there are a ton of threads on how the transistors work loose from heat expansion / contraction. I couldn't find the big thread - something like "...Do you know where your FSD / PMD is?... "

[Norwegian Bow-tie]

I see. Thanks to everybody for their answers so far. Nice to discover that my english isn't that hopeless. :)The thing is though that my FSD was replaced under warranty in May. The truck has been flawless since then. The official GM dealer in Norway did this, and now the engine cover is gone and the FSD is mounted on a separate cooler on top of the engine. I know some of you have put it even further away with a harness, but still. Should I take it to the dealer again? Money is really an issue.

[JohnC]

When the FSD starts acting up, one of the symptoms can be variations in the solenoid closure time. the PCM is programmed to disable the cruise if this happens because it can result in an inability to control engine speed. In the extreem, the PCM shuts off the fuel shutoff solenoid killing the engine.

Another common cause of random cruise failures is a flakey brake switch, which, IIRC, has 3 separate contacts.

[Norwegian Bow-tie]

Another common cause of random cruise failures is a flakey brake switch, which, IIRC, has 3 separate contacts.
How can I check this? Pictures?

[jjbouwens]

Somewhere in Norway there is a guy Roy Halvorsen he took apart the injection pump try following link:
http://www.mamut.com/homepages/Norway/3/4/royh/newsdet9.htm
I cannot get closer to his home page. Good luck. By the way the brake switch sits close to your right foot on the steering column.

[Norwegian Bow-tie]

Originally posted by jjbouwens:
Somewhere in Norway there is a guy Roy Halvorsen he took apart the injection pump try following link:
http://www.mamut.com/homepages/Norway/3/4/royh/newsdet9.htm
I cannot get closer to his home page. Good luck. By the way the brake switch sits close to your right foot on the steering column. I don't know this guy, but I have seen his car smile.gif He lives just two miles from me. I found the switch and sprayed it with "electro something" Now the cruise control works. I don't know for how long but I'll keep my fingers crossed. Thank you everybody for answering me!

[CareyWeber]

Check the little things first a dirty speed sensor in the trany/transfer case can cause curise control issues as can the multi-function switch (turn / wiper / cruise switch).

I had a P0251 SES code and everyone said time for a new pump, but I found four wires that were rubbed bare and when I resealed them no mode code and thats been about 16 months ago. ;)

Carey

[LanduytG]

Something that I have found as well is if the torque convertor is not locking it will have a slip code (can't remember which one)and cruise will not work. Clear the code and it works fine.

Greg