Anybody familiar with Newer GM cruise control troubleshooting? I recently purchased a 1992 Buick Roadmaster Wagon which is a great riding and driving vehicle. The only problem I have found is with the cruise control. It is what I would like to describe as partial cruise control. You set it and it holds a speed for anywhere between 30 seconds and 10 minutes but then disengages eventually. It holds a steady speed while it is working, it just shuts itself off. I had a similar event on my 95 Taurus that turned out to be related to the clockspring in the column. Anybody have any thoughts or experience with this? I am going to post this on another site for the B-bodies as well. Thanks you in advance!
Does it shut itself off while driving on a flat survace, or does it do this when starting up a slit incline. It may just need the cable adjusted. Mike
Check the cruise control release switch (10024217) at the brake pedal next to the stop light switch. Its acting as if it is loose or the connection is not secure. By your description the module seems to be working because you do have cruise but its releasing due to the other. Thats my 2 cents............. David
My old dodge caravan used to do that. Finally after it quit working completely, it ended up being a speed sensor.
Not sure when GM changed their cruise control design but my 88 Astrovan and my mom's 90 Lumina both had the same system with the same type of problem you're having. Replaced the transducer ( vacuum operated part that pulls the throttle). Fixed the problem. If you've got the same system the transducer is about 4-5 inches in diameter and has one wide electrical plug, a vacuum connector, and a cable which runs to the throttle body. Very common for these to fail, probably 90% + chance that is what is wrong. At one time I heard these were available remanufactured but I couldn't locate a supplier when I needed one so I went to a wrecker.
I'd start here, as well as checking the vacuum lines to the transducer. My '01 Vette also had a problem that I tracked to a transmission range switch (sensor on trans that tells PCM what position the gear selector is in). I had bumped the adjustment when I swapped converters, found the problem right away when I hooked up my diagnostic equipment.
It's most likely NOT a vac. operated system... I too would put my money on a brake light switch that is adjusted a bit to sensitive... Check that out and see what happens. regards
Here's something you wouldn't think... ...even involves the cruise control. I've seen too much resistance in the brake lamp switch cause trouble, also. This system should be new enough that it doesn't use a vacuum operated module. It uses an electronic control module (it's the black box on the cable actuator). INTERMITTENT/NO CRUISE CONTROL - REPLACE CHMSL BULB #92-8-160 - (07/15/1992) SUBJECT: INTERMITTENT OR NO CRUISE CONTROL OPERATION (REPLACE CHMSL BULB, ADD RESISTOR ON WAGONS) VEHICLES AFFECTED: 1992-93 "B" CARS CHEVROLET CAPRICE SEDANS AND WAGONS OLDSMOBILE CUSTOM CRUISER WAGON BUICK ROADMASTER SEDANS AND WAGONS CONDITION: ---------- The cruise control system may not operate on the 1992-93 B-cars. On wagons, the cruise control may be intermittent, may drop out while driving, or may fail to engage. CAUSE: ------ The ground for the brake switch signal to the cruise control module (part of the stepper motor assembly) goes thru the Center High Mounted Stop Lamp (CHMSL). If the stop lamp bulb is burned out, there will be no ground path for the cruise control. On wagons, the contacts for the CHMSL on the tailgate glass may corrode, causing intermittent operation. Adding a resistor will allow a ground through the brake switch without going through the bulb. CORRECTION: ----------- On both sedans and wagons, check for operation of the CHMSL bulb. If the bulb is burned out, replace it. This should correct the inoperative cruise condition. WAGONS ONLY: 1. Disconnect the negative battery cable. 2. Remove the left rear quarter trim panel, as shown in Section 10-7 of the Service Manual. 3. Locate the blue 8-way connector (C405), as shown in Figure 1. Find the yellow wire in cavity A, and the black wire in cavity F. The complete circuit is shown on page 8A-110-4 of the Service Manual. 4. Obtain a 390 ohm, 2 watt, 5 percent resistor from a local electronics supply store. Splice the resistor from the yellow wire to the black wire, as shown in Figure 2. Be sure to solder the connections, then tape the wires. 5. Reinstall the trim panel, then reconnect the negative battery cable. For vehicles repaired under warranty use: Labor Operation: N-0768, Time: 0.2 Hr. CHMSL Bulb Only Time: 0.3 Hr. To add the Resistor Figure 1 Figure 2 General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit
The high mounted third brake light and brake mounted switch are the two places I will look at tomorrow. By the way, the wealth of information present within board members is staggering, in case anybody has not noticed.... Thanks again Buick Guys! Also thanks to the General for running the cruise through a taillight. Kinda like ford running it through a clockspring on the steering column. Well at least that is in the same general area of the car....
It happened to mee with a Saab ans a Jag: Every time it came (as David sugested here above) from the loose break pedal touching the switch that disengages the cruise control (which is different from the one for break lights). Slighly shake the pedal with the foot without breaking while driving and see if the cruise control turns off...
After reading this, my '67 is looking better every day. It's amazing how they could make a cruise control 40 yrs ago with one transistor and a couple switches that works just fine. Today it has to be connected to a computer and be dependant on a light bulb in the rear window in order to work. I guess I made the right decision when I gave up the field 15 years ago.:moonu:
