Beatle

Hi I have a problem with the cruise control 2001 Automatic . I have done all the checks that I have seen on the site . I have 12 volts at pin 3 when the servo is pluged in. I also have ground at pin 4. No vacuum leaks. Brake switch works it kills the 12 volts to pin 3 when depressed. When power is on pin 3 the other terminals have 12 volts sounds right also. History on Cruise problem work fine pulling great and just dropped off. When I turn on the cruise button the cruise on light comes on dash. But set does not work. I have tried all other items seem to work. Horn , Vol controls work and Radio channel changes. I think the Clock spring is ok. The only error I had after the cruise failed was p0500 vss speed but can't check it out not enough info on it and will not show a code again. Odometer works fine at the time I was towing heavy after the cruise failed and I was parking the trailer and the tires did spin on grass maybe this cause it but every where I read it says the VSS sensor is not used but it is in the transmission seems odd. I have never seen the p0500 error ever sinse I have owned the truck? Just wondering is there any way to prove the Cruise Servo is working maybe ground pins 1 or 2 not sure just want to get the Vacuum to move the cable. Just cant figure it out maybe you have a few more tricks you know of. I was going to try unplugging the rear end speed sensor in the rear end to see if the VSS takes over then it might fail. Any help would be great I am at a lost.

hamilton71801

Mine stopped not too long ago and threw the 0500 code and I blamed it on the clockspring, but everything else worked. Finally after a week or two, it started working again. I had pretty much tried everything I knew to fix it and my last resort was kicking the snot out of the tire...

Beatle

bump

Beatle

Update I now have gotten the Vacuum servo checked for sure.The PCM duty cycles the vacuum and vent solenoids
to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. I tested this today if I put ground on pin 4 and power on pin 3 and ground 2 and pin 1 and put vacuum to the servo it opens fine. It looks like something else don't know where to go from here. Might be the clock spring or wiring on the set button but the on and off cruise use the same button and wiring path as the set button then they go to PDC.

swordfish

I am just shooting from the hip here, not sure exactly what the VSS Speed error code is, but I know on some vehicles they won't set the cruise below 45 mph. Is it possible the pcm is seeing a lower speed and not allowing the cruise to engage? Like I said, shooting from the hip, but that was the first thing I thought of when speed was mentioned.

swordfish

Beatle

It might be but when I unplug the VSS sensor I get the p0720 A/T Output Speed Sensor - Low Output Above 15 MPH. But there is not enough info on the sensor. I Just hate to take it to the ******* Ship. Anyone else be here and tried other items.

Beatle

bump

Beatle

Well finally fixed the cruise had to take it to the dealer. I had it narrowed down to the cruise servo but I decided to take it in. Took it to a old Dealer out of town in the farm area so they sell a lot of diesels in that area. It took them a hour and they told me the servo was bad. I also got the Three Cylinder Warm up activated did all of this for 100.00 dollars so I was happy. The quote for the new servo installed and tax in was 333.38. I already knew I was on the way to Auto Salvage Yard 45.00 like new. Got one off a 2003 intrepid the first one I got had the old style plug it would have worked but I would have to chop out my plug and wire in the old style. The 2001 has the locking red tab on plug. Took it home and converted it over to my cable after tearing out the battery for the third time good thing it only takes 15mins. Connected the battery and started the truck up hit the cruise one and the light came like it did before. Took it up to 30km and hit the set button and cruise works again. Funny thing is I been without cruise for six months and I have missed this feature every day on the Highway. I hate having something not working on the truck. Just a note to everyone sometimes you can get a good dealership to help you pin point the problem. Cruising for now.