OK team, I am having intermittent problems as well. Mine works until I drive for say an hour then it just decides to disengage. I hit resume, it resumes. So with that I am thinking not a problem of power supply to the module, otherwise it wouldnt resume. The brake light switch is working and adjusted properly...why the intermittent disengage.????

 

Automatic or manual transmission?

What I'm thinking is there's a switch on the clutch pedal that disengages the cruise. If that switch is adjusted too close (hair-trigger) it wouldn't light up the brake lights.

Even with an automatic, you think the switch is OK but have you had a friend drive behind you to see if the brake lights come on together with the cruise disengaging.

 

id say thats a pretty good clue if u can make it work by lifting the pedal up...i mean cmon !! i think that post must have been a sting run by the DOT !!

 

Kellyned posted into an existing thread. I didn't see anything HE said about lifting up the pedal to make it work.

 

Its a 98, 2.3L automatic, I can hold the brake pedal up and it still does it, looking at the switch it cant be adjusted any closer to the brake pedal itself..its down all the way already. I am however going to replace the switch, then the module..I am gonna work my way through this system..

 

Don't necessarily replace the switch, if the brake lamps work properly. You can test the switch with a multi-meter to see that it's operating correctly (or not).

If you rule out the switch, then it would help to have a circuit diagram for the cruise system and see what else can trigger it to disengage.

 

Please remember the brake switch has what I call three positions.

One: brake lights on....as if you are pressing the pedal.

Two: This is the important one and the one that gets confusing. I call it the "zone of indifference". Meaning, no brake lights on and NO cruise. Brake lights are off but the cruise will not work.

Three: Cruise circuit complete. In this the two pins (of the four) on the brake switch that go to the cruise have continuity...and the brake lights are still off.

So me, do you happen to notice that when the cruise stops....did you hit a "dip" or some part of raod that is uneven....bouncing the car in anyway?

 

there are 2 separate switches inside almost all modern cars brake pedal switches especially with those equipped with an ABS or eeven newer stability programs.. if theres an air gap between the tab on the pedal and the switch itself and the cruise is STILL intermittant id simply replace the switch without messing around with a meter..that switch is probably the most worked switch on ANY veehicle and some brands just dont seem to fare as well as others..ive replaced hundreds on Mercedes vehicles where the cruise was inop but the brakes lites still worked.. yours being 4 pin means exactly what it should mean..

 

having different brands of tires from front to back or even side to side will make some cruise systems give up after they warm up it depends on how much different the OUTSIDE diameter is this applies only to modern 4whl ABS equipped vehicle whether it uses a cable or a sensor to run the speedo