My cruise control Stopped working. It won't turn on.

no year stated, wow.
the first checks are not the CRUISE.
they are:
1: all fuses good.
2: CEL lamp out driving, if not the PCM will in fact cut Cruise function ( preventing TOYOTA SYNDROME)
3: scan tool do a full PCM scan, got errors. got DTCs, bingo.

today cruise is the last to work, (a very serious safety issue)

by cruise control being PCM control have dealership code scan see what causing cruise control turn itself on.

I just got the perfect answer to this yesterday. It's a $5 fix! Check your brake lights. If any of them are out, it will make the cruise control not function. Turns out all 4 of the 3rd set of brake lights were out. We replaced the 4 of them and the cruise control immediately became functional again. I got this tip from a gentleman in the service department at a local Chevy dealer.

This is more likely your entire turn cruise wiper switch, you can get them on ebay for around 50 dollars!!

The Dashboard light dimmer control is probably stopped working because one of the tiny eletronic bits inside it has died. A temporary fix is to remove the connecting plug on the rear of the unit and put a bridging wire across the terminals. The cruise control problem could have several causes. They operate on engine vacuum so check the hose going to the cruise control unit in the engin bay from the inlet manifold. If the hose is cracked or hard there will not be enough vacuum to operate the cruise control.

Check the switch, located on the brake pedel the stop light switch and the cruise control switch are on the brake pedel towards firewall. The cruise control switch is plastic.

Do the brake lights work now, as they should? The brake light switch generally triggers the cruise control to snooze.

Check to see if your brake lights are staying on.
I thought my cruise control stopped working too, but realized that it would not work because the brake light control on the brake pedal was stuck.
I changed the $40 control and the cruise control works.

I had a similar problem with my 99 Suburban. After not being able to solve the problem for about six months, my headlamps stopped working on the low beams. This led my mechanic to change the multi-function switch on the steering column (turn signal/cruise control switch/high beams) When he did this he discovered that the wire terminals at the switch had gotten hot enough to melt a little, this allowed the ground terminal to slip out of the connector. Once replaced, the cruise control miraculously started working again. I have had no problems with it for the last four years. The local GM dealer told me later that they had quite a few trucks with the same problem and it typically started with customers noticing that their cruise control stopped working. Give this a try!

use a scanner to check the abs system . most of the time the abs brakes and traction control system work together. your cruise control . unit has a servo motor .in front right fender well. check the fuse and relay also the cruise control brake release switch. and the brake light switch.if all is good you have a cruise control module problems. dealer ship job.