2nd Gen Non-Engine/Transmission Servo-less cruise problem

[Archive]

Hi all!



My cruise control is no longer working, but the dash light still works fine. I have a 2001. 5 HO truck and I don't believe it has a vacuum actuated servo. Any suggestions?

 

[Mundgyver]

Do you have a maintenance manual for your truck. On page 9-235 of the 2001 manual, it states that the "Vacuum pump output is transmitted to the HEVAC, speed control, systems through a supply hose. "



I would suspect that you have a vacuum servo. There is an electrical connector to the servo that opens and closes a vent. When closed you engage the diaphram to draw on the throttle. This vent will open and close many times during cruise operations. Provided you do not have a cracked line or one that has come off, you should be able to put a vacuum gage to it and check it.

 

[parcher]

Later STICK SHIFT trucks do not use a servo, rather the pcm "remembers" engine rpm when you set the cruise. Since it will cancel cruise when you clutch and there is no torque converter to slip, rpm=desired mph. With no throttle cable, the pcm sets your desired rpm as a target thus giving you cruise. With a DRBIII one could read why cruise was dis-allowed.

 

[Mundgyver]

Interesting, I would have thought that it would have been a vacuum servo. I wonder which is more reliable in the long run Vacuum servo or electronic

 

[illflem]

Many times the brake or clutch pedal switch is out of adjustment and is signaling the cruise to shut down. In the early stages of the problem the cruise will be canceled out when you hit a bump.

 

[Mick2500]

Grease,



The 2001. 5 electronic cruise control will work just fine with a shorted clutch switch. I disabled my clutch switch when the truck was about 1 month old. I hated the fact that I had to be in the seat to depress the pedal just to start the truck.

I installed a jumper on the switch to simulate the pedal being depressed all the way. The 'switch' is actually an inductive switch and it detects movement, not just full travel or partial travel. As you depress the pedal it creates a signal in the sensor and turns off the cruise.

Everything works great except that the clutch pedal no longer disables cruise. I'm not sure what would happen if the switch was open.



Mick