Ok, guys - I need some help with my Cruise Control. Do a lot of highway driving lately and need this system back up and working correctly.

193k mi, original engine, 13b RE-EGI (sig line for the rest) - symptoms are; When cruising on the freeway, push the Cruise Control Multi-function stalk button in to SET speed and when released, the car coasts down - not SETTING. Hold the SET button in and the car does nothing for a second, then accelerates rapidly, which it should (this is the ACCEL button, too). Release SET button and the car coasts down again, not SETTING.

Any hints/tips/tricks?

I have a spare set of solenoids at the firewall, and have already replaced the diaphragm actuator without improvement. The Cruise Control module under the driver's bin area is clean, plugged in, and seems to be working correctly.

I'm thinking I need to start swapping firewall solenoids, but defer to the forum for assistance. Let me know, and thanks in advance,

 

Alright - all 24 of you guys who read my post and don't use your Cruise Control systems anymore; want to send me yours?!?

Seriously, though - any tips for me? Any suggestions on which firewall solenoid might be the 'SET' and which one is 'COAST' and 'ACCEL'? TIA,

 

I removed mine also, just kept my eyes on the speedo and my right foot gentle.....lol

Not much help though sorry.

 

i removed mine also i couldnt figure waht was wrong with it but if i can find all the parts for it i ll be more than happy to send them to you!

 

well, homeboy HERE looks like he may be getting rid of his soon ... it's a oretty thread, just hours old.

 

Those solenoids on the firewall are for the ACV. The ones for the cruise are built into the actuator itself. The plug should have 4 wires (BrR, BrY, BrB, and Br). We know that the actuator seems to work. Also, the set button functions as the car accelerates when holding it down. I would try to replace the CC control module. If it were the clutch switch, brake switch, or similar that was bad, I don't think the car would accelerate holding down the button (safety feature).

The other possibility is maybe the speed sensor in the instrument cluster is bad. That may explain why the CC won't engage. Good luck.

Kent

 

Having spent some time studying the Cruise Control system, it looks like it takes vacuum off of the lower intake manifold, routes this through the 2 solenoids on the firewall with one vacuum lead going to the actuator. Though there is a 4-wire plug with the wires you mention, the vacuum going to the actuator is actually controlled by the solenoids INSIDE the actuator???

Maybe my ACV solenoids are messed up that's causing air to not get through to the actuator.

I'll have a look at that tonight and appreciate the leads,

 

definitely let us know what you find, I'm sure we'll all want to know. I've never done troubleshooting on a Cruise system before, but my friend Eric wants to get his active this spring. Probably archive worthy too.

Jon

 

I took the cruise off a 84gsl, and put it on my gs, no external solenoids, just the box behind the seat , the pedal switch, dash switch, and unit under the hood.
Could be the stalk switch itself is bad/dirty?

 

Well, actualy both cars had no rats nest, so thats not entirely true, but when I did the switch, I searched and couldn't find any solenoid specifically for the cruise.
Anyhow, it works without one.

 

The wiring diagram shows the solenoids in the actuator. There is 1 vacuum solenoid and 2 vent ones, I believe. Basically, if you have replaced the actuator, it is either the control module or a sensor. Most sensors would keep the CC from working at all (clutch switch, brake switch, and so on). There is a speed sensor in the instrument cluster that the CC uses. I imagine if it wasn't working, the CC wouldn't engage but the acceration part should still work.

I think there is also a diagram in the FSM to check the switch. I imagine that since the acceration part is work, the switch is fine. I would try to replace the CC module first.

Kent

 

Okay, sorry to bring back a dead thread, but I am also working on the cruise control(as I stated in another post I recently made). Never trouble shot a cruise control system before, so this is completely new to me. From what I think I've gathered here, the drivers side bin has some parts to check, the solenoid area has a vacuum hose for it, and there is a diaphram to check, right? Where is the diaphram? I have the Haynes manual for her(82 GSL) and it says next to NOTHING on Cruise control and this is the closest thread I found via search to fix cruise control probs. The closest thing to CC in Haynes is a diagram on pg 256 and it only says "to cruise control" on a vacuum hose near the solenoids. I know CC is not really neccessary, but I'm thinking on some of my longer trips I make in the FB, CC would be great to avoid cop attention as well as save a few dollars on gas.

 

OK, update. Went into the car. Opened up the driving bin behind the driver. I have the computer there and it's hooked up. Popped the hood and found the hose the haynes manual says is "to cruise control." In the book it shows it capped off(which I'm assuming is because they don't show how to work on CC so they show what a model without CC looks like, but I'm not sure). In my car there is a hose on that fitting, but it doesn't go anywhere. It was located around the solenoids and then ran up to the bottom of the carb, but when I stuck my head in the engine bay to look where it was hooked to I noticed it wasn't hooked up at all. It just sat there. So I puled it away from the engine and used a flashlight to look all over the engine block and carburetor...no empty hose fittings to be seen. Does anyone know where this hose is SUPPOSED to be mounted? The engine was supposedly rebuilt at 100k miles, but not replaced...so I'm hoping it didn't hook somewhere on a carb that might have been replaced...I don't know if he replaced the carb or not, but I can't find the fitting for that hose. So if anyone knows where this hose is supposed to connect to or if someone knows if it's even supposed to be there that would be a huge help on my learning experience. If I need to cap it I have caps. If it IS supposed to have a location, where is it? Thanks again in advance if anybody knows.