Cruise control shuts off randomly

isuzu

#1

I have an 2008 Isuzu i290 (essentially the same thing as a Chevy Colorado). I bought it new in '08 and it’s had (mostly) regular maintenance.

There was a recall for the brake lamp switch for Isuzu i290’s a while back. In addition to brake lights not working correctly with the faulty switch, the switch also affected people’s cruise control (the CC just stopped working completely when the switch went bad). I replaced the switch about a year ago and have not had any trouble with the cruise turning on since. My brake lights work fine and my cruise turns on with every attempt, so I don’t believe the switch is bad.

However, recently my cruise control has started randomly shutting itself off. I can immediately turn it back on and it will work for a random amount of time before shutting off again. I commute to work, so I do most of my driving on highways in 4th or 5th gear, and this is when I generally use cruise control. I don’t know if it’s only shutting off in 4th and 5th gear, or if it would also shut off in lower gears. Sometimes I can drive the 50 miles to work and it works perfectly, and sometimes it might turn off as many as 4 or 5 times. It seems to happen more when I am going uphill, but it sometimes occurs on flat areas. I don’t recall it happening on a downhill slope, but I couldn’t say it’s Never happened. I tried shifting to 4th to increase the RPM’s when going uphill, thinking perhaps they were too low as the engine worked to pull the truck up the hill, but that hasn’t made any difference. Also the amount of fuel in the tank doesn’t seem to matter.

I know I’m not accidentally bumping the brake or clutch, since I started paying close attention when it started happening and I am certain it’s not the cause.

Can anyone please advise on what may cause the cruise control to randomly shut off but then have no trouble turning right back on? Thanks!


#2

The next time the CC stops working, place the your left toe behind the brake pedal and pull up the brake pedal.

If CC doesn’t shut off, the problem might be with the brake pedal switch.

Tester


#3

I had the same problem with a 03 Passsat. After a recall to replace the brake switch, the cruise control started failing. Took it back to the dealer and they fixed it. My assumption is that there was a bad connection made when they replaced the switch.

Take it back to the dealer, this is related to the recall.


#4

As above, I’d guess this is most likely caused by the CC thinking the brakes have been applied. Problematic wiring, fuses, or switches in that circuit.


#5

Could be the switch on the brake or clutch pedal. Maybe one or the other is not returning quite all the way or the return spring is weak and just hitting a bump or dip in the road jars the pedal enough to release the switch.


#6

The brake light switch (or adjustment) is probably to blame.


#7

I think the brake light switch needs to be adjusted. As the car ages the brake petal return spring maybe getting weaker and the petal isn’t being pulled back fully or as strongly. Since you are driving you can’t see whether the brake lights are coming on or not, but I suspect that sometimes the brake lights flash a bit (perhaps when you hit a bump) and that is all it takes to knock off the cruise. The switch should be adjustable to compensate for the change in brake petal travel.

The same might be true for the switch on the clutch petal.


#8

Make sure your center brake light is working, a bad bulb will disable the cruise control.

Ed B.


#9

A bad brake light bulb will disable the CC? I wonder why they’d design it to do that?


#10

To let you know you have a brake light out?

Tester


#11

And who would associate a mal-functioning cruise control with a burned out brake light? Not me.


#12

As always…Tester probably nailed it yet again. He’s sharp that one… I was thinking the same thing. I had a similar issue with my cruise in my VW…they recalled the brake light switch bec of problems. I have no issues w my cruise buy if I hit a substantial bump…it will shut off. My car is a “Fly by Wire” system…so my cruise may be more complex than just a brake switch cutoff…probably IS.

Do testers recommendation and let us know…if thats it… your switch is adjusted to be too sensitive…easy to back it off a bit to adjust it.

Blackbird


#13

The brake switch adjustment may very well be the solution to the issue but since you have fairly recently had that switch replaced I am leaning towards the clutch switch as the culprit.


#14

Im leaning toward the switch because…someone just messed with it… Almost more likely now in my opinion.

You will figure it out… Probably by doing what Tester told you to try. Let us know…we love happy endings

Blackbird


#15

You might very well be right about that Blackbird. I am just thinking the vehicle is about the right age to have that kind of issue happen since the switch hasn’t been worked on. Either way, the trouble is most likely due to one of the two switch adjustments.


#16
And who would associate a mal-functioning cruise control with a burned out brake light? Not me.

When a customer complains that the CC has stopped working, the first thing that’s checked is if any of the brake lights don’t work.

Tester


#17

It does seem a bit odd for the car’s designers to decide to turn off the CC b/c a brake light bulb is burned out; but I guess it’s a way to get the customer to the shop to get the bulb working again so it makes sense from that perspective. If just a dash light were turned on the customer mike ignore it and end up with a ticket for no brake light, or worse, somebody crash into them from the rear.


#18

I do think that the mfg’s DO or Have implemented the CC shutdown upon a bulb burning out. I experienced this about a month ago…had me looking at my fuses and brake lights wondering why my cruise didnt work. Guess what? I discovered a bulb burnt out in the back.

Pretty cool and effective even though it wasnt my first thought as a suspect…it definitely led to it quick enough for me.

Blackbird


#19

We just replaced the brake light switch a few months ago, so I would hope it’s still functioning correctly, but I’ll check it anyway. Unfortunately Isuzu pretty much left the US several years ago, so there aren’t any dealerships within 100 miles of me, so taking it to a dealer isn’t an option.

Also, if it’s helpful, it’s started happening a lot more frequently in the last week or so. Still seems to only happen when going uphill.


#20

The next time the CC stops working, place the your left toe behind the brake pedal and pull up the brake pedal.

If CC doesn’t shut off, the problem might be with the brake pedal switch.

Tester, to clarify: Next time it shuts off, I should turn it back on, then life up on the brake pedal?

Thanks!