2009 Chevy Malibu. My car’s cruise control kicks off at random times. The control on the steering wheel will not re-engage the cruise control. It stops working until some random time down the road when I can finally reset. The tach will jump from 2 to 3 and seems to feel like it is shifting gears. The dealer reads no codes. How do I get this fixed. I drive interstate all week 50+ miles everyday and it is annoying. PLEASE Help !
The next time the cruise control stops working, take the toe of your left shoe and place it under the brake pedal and lift up on the brake pedal. Now try engaging the cruise control. If the cruise control works the brake pedal switch is either defective or out of adjustement.
That may explain the cruise control shutting off or not re engaging. But, why would the erratic shifting and tach jumping be caused by the brake sensor.
I will give it a try, thank you very much for responding.
Sometimes it’s a component, sometimes it’s a ground connection or a bad power connection. The ground connection from engine to body used to be a good one to check and clean.
"But, why would the erratic shifting and tach jumping be caused by the brake sensor. [?] "
I believe the switch referred to is a Torque Converter / Cruise Control Release Switch. That could explain it.
There may be a problem with a speed sensor that is causing the tach to have change in RPM readings.
Tester; I tried the brake lift and it did not work.
pleasedodgevan2; where is that connection located ?
common sense answer; Would that be a cause of both problems ??
Cougar; same question I posed to common sense answer, Would that be a cause of both problems ??
I assume the Tourque Converter / Cruise Control Release Switch and the Speed Sensor are two different things.
A bad speed sensor could cause both of the things you describe to happen I believe but since you aren't getting any error code then perhaps the speed sensor may not be the problem. I think you would see an error code of some sort if the sensor was having a problem. The advice that CSA gave may be more on target to the trouble.
There are a number of things that the cruise control watches for a change and will disengage if say the brake pedal is pressed. Since the only real clue you have for the trouble is the shifting I would check out what the cruise control is monitioring in the transmission area using the electrical prints and go on from there. The trouble most likely is due to a faulty electrical connection somewhere and in an area that won't generate an error code. There may be a connection to the brake switch that could cause it if there is a tie to the transmission control unit from the switch but I would think an error code would show up if that was the case.
Have had it in the shop twice and both times has shown NO CODE. So, the likely culprit in this case could be a faulty wire connection somewhere. How would the shop trace that down.
Or the Torque Converter / Cruise Control Release Switch as CSA mentioned.
What should I tell the dealer to look for when I take it back ?
I have a video of the problem happening on the interstate but I can not attach file to post as it says "Uploaded file type is not aloud".
If the trouble isn't happening while the shop has it then they may not want to work on it. Looking for a problem that isn't happening at the time can run into a lot of wasted time and needless parts replacement. That relates to high shop bill for you and possibly having the trouble still there, waiting to happen again.
The best clue I think you have for the trouble is the shifting of the transmission and RPM change. The shop needs to know any clues like that you may know is happening when the trouble occurs. If I was the tech working on it I would focus on the relationship between the cruise control and the transmission and how it can disengage the CC.
Thanks everyone for your help and posts. I will keep you informed of the outcome.
Update: 6-8-11. Driving this morning, cruise control would not engage at all. Every time the car would get to a speed to shift from 5th to 6th it would kick back into 5th and the tach would go from 2 to 4 RPM.
I hope this is only a sensor problem and not the transmission. Hopefully if it is transmission, it would be covered under a warranty. Don’t know what powertrain warranty miles are ??? 50,000 ??? 100,000 ???
I Believe That Warranty Is 5 Years / 100,000 Miles On The Drivetrain.
If the CC isn’t working then it would be good to get it into the shop so they can check it out since there is a trouble they can now look for.
The cruise control worked this morning but when the car would release the gas to coast on even ground or downhill. The car would shift gears down and the tach would rev high and the cruise would kick off. I could manually accelerate and get the car to shift back into a higher gear and it would work again.
The dealer says no codes are showing when I have taken it in the past and you can’t predict when the cruise will malfuntion. I am stuck with no repairs due to no codes and a car that gets 112 mile days and an aggrevating cruise control.
It is interesting you say the CC takes over again when you manually accelerate the car. This makes me wonder if something is going on with the vacuum system going to the CC. Perhaps there is a small vacuum leak causing the trouble.
While it is very helpful to have clues to a problem by looking at some generated error codes many times that doesn’t happen. A good tech will know how to find problems without needing code errors to go by. You may need to find a different dealer to work on this issue or wait until the trouble is present at all times.
Clarification/Correction. The CC would eventually work again. Not right after the manual acceleration. Sorry about the misleading description.
I noticed this morning, the shifting and revving would happen going from 5th to 4th gear on flat ground or downhill. If I eased up on the accelerator and not let off completely, it would shift down from 5th to 4th and possibly once to 3rd on interstate at 70 to 75 mph speeds. Only once did I notice it going into 3rd and that is when the car slowed to a speed of 65, tach went to 4. Obviously at these times the CC would not engage from the buttons on the steering wheel.
No codes and extremely frustrating. It seems to be getting worse and more frequent. Maybe I will let it go to the point where it is happening more often so the dealer can test drive and see that I am not crazy in what I say is happening. I just hope that it don’t damage my transmission in the process.
NEW DEVELOPEMENT: I noticed while driving at night that my third brake light was on and my foot was not on the brake. I had an idea to engage the cruise at this time to test if it worked. It did not. I tried to lift the brake pedal with my foot as TESTER had stated to try. It stayed on. I tapped the brake and the light went off and was able to engage the cruise, although it did not last long before it came back on and the cruise shut off. So, TESTER may have been correct with the brake issue. Still, the Chevy dealer has said that no codes are given when they had it in the shop. What should I tell them to try or look for when I describe the symptoms of the problem? Please help, this is getting very annoying, plus it my be cutting into my gas mileage if I am riding the brakes for 112 miles everyday.
If the switch won’t disengage properly by lifting on the pedal, either it’s position needs to be adjusted, or it needs to be replaced.
This is a huge clue to solving the problem. I assume the other brake lights were on also and not just the middle one. If adjusting the brake light switch doesn’t work then you may need to replace it, like Chaissos stated, as there may be a internal problem with the switch contacts.
A lot of electrical problems like this won’t show any error codes since that don’t relate to the ECU and engine operation. Having good clues to the trouble, like seeing the brake light on, is the kind of thing that helps locate and solve these kind of problems. Good job on spotting that. You have found the source of the trouble. Tell the service folks the brake switch is turning on without the brake pedal being depressed. Either the switch adjustment is wrong or the switch is faulty.