Went by the book, Type A diagnostics all Ok until number 4 dealing with cancel switches. This includes CC Cancel, emergency brake, clutch pedal, don't think neutral safety applies to 5 speed. I get no response from any cancel switch. When driving everything appears normal, turn on cruise, cruise light comes on, hear relay click. Push set, nothing happens. This is why I did not do Type B diagnostic, that indicates if you get 5 flashing cruise light, then malfunction has occured, I don't get that that indication when driving. Type A diagnostics are sitting still diagnostic. Any ideas as to why I can get no indications of cancel switches?

 

Lemme get this straight. You attempt to engage the CC , hear the relay click but doesn't engage and you get no diagnostic light from the CC computer. Check to see if you have vacuum leaks around the unit under the hood.

Also, a malfunctioning Brake Master Cylinder Fluid Level Sensor ( the donut in the reservoir) can cause the CC either not engage or immediately disengage if the sensor 'thinks' the fluid level is low. This sensor (donut) gets a hole worn in it over time, begins to fill with brake fluid and sink. You can disconnect the Sensor plug from the harness to see if it is affecting the CC.



Mike in AR

 

Thanks for replying Mike. Tried that. This is where i am at now: no bad vacuum lines, Actuator tested OK although a little over ohms, Vacuum pump tested OK well above spec, so it's good and strong, Brake fluid level switch tested OK, vacuum switch tested OK. I can hear relay working, but have not tested. Also have not tested brake, emergency brake, clutch switch. Although brakes do light bulbs, I think there is another side that has to be tested. I thought I felt it try to engage today, but it didn't hold, kinda sputtered or stuttered. Will test other components tomorrow. Still no codes in CC diagnostics. Any other pointers? I'm leaving speed sensor to last, dread that one.

 

You are right. There 'is' an E-brake set switch down on the firewall. I changed mine, but turned out to be the MC donut sinking when it sloshed around, driving down the road.

Does your E-brake warning light illuminate on the dashboard when you turn the ignition 'on' and/or when you set the E-brake? If the bulb is out, you may be getting a signal and not knowing it.

( I can sympathize with your problem. My CC would 'mysteriously' cut off and the E-brake light would flash at the same time. Drove me nuts for about 2 wks until I discovered it was the MC donut (sensor) I also got no CC computer codes.)

Mike in AR

 

Yes it does light. Still investigating. It's nothin under the hood. Running tests on the pump, actuator and vacuum switch actually powered up the pump and pulled the cable. No leaks. Even though diagnostics should show something, it doesn't. I checked the brake fluid doughnut and switch and they are OK. Just for giggles, I'm going to unplug it like you said and try it. Rain and hail here kept me from doing to much outside work.

Tried unplug of brake fluid switch, no joy there. I think it's one of the cancellation switches (emergency brake, brake, clutch, CC Cancel). What makes me think this? Putting CC in diagnostic via key on, hold set/coast and press Cruise button turns on diagnostics. Step 1, press set/coast (chart didn't specify, but you have to hold it) gives 2 blinks. Ok, normal. Step 2, press and hold resume, 3 blinks, normal. Step 4 5 blinks, actuator OK. Step 4 says press Cancel, brake, clutch and emergency brake. Here is where it get muddy. Chart is not clear as to do each seperate or all together. Tried both and get no indication like chart says. Light at this point should be solid on or solid off (very unclear, but if either is correct, it don't do it.) This either indicates all are bad, which i doubt or 1 is bad keeping cacel signal going. My theory is most likely clutch switch first, then brake. Have to wait til weekend to take lower dash apart, can't get to either of those switches unless I do. Doubt it is emergency brake because it's just 2 prong and light works on dash when pulling brake. also turns on with ignition indicating good light.
Any tips, previous experience sharing would be welcome.

 

Any experience out there with bad switch described above?