When you are saying the cruise will not turn on, does the indicator in the dash come on when you turn the system on, and it will just not set on the speed selected? Or does the indicator not come on either?
This is going to cause the issue to be different, so we need to start with this.
The way I read the issue is the indicator comes on but it does not set the speed.
If this is the case, then this is most likely one of two issues. First and foremost, it is the brake switch or deactivation switch.
The brake pedal switch is on the brake pedal arm, and it tells the vehicle if you are pressing the brakes. Sometimes these stick on slightly and if it thinks you are pressing the brakes then it will not turn the cruise on.
You can test this by checking the voltage coming out of the switch. It should be an open circuit unless the brakes are pressed.
The same thing with the deactivation switch. When this fails, it thinks the system needs to be turned off and so it won't allow you to activate it. This can be tested by just unplugging the sensor and jumping the switch terminals in the connector to see if the cruise comes on.
The other common failure when the light comes on in the dash is the servo. Basically, it just doesn't engage the cruise.
Please see the info attached for this including the wiring diagram so we can start testing if needed.
Please see the attached below and let us know what you find with this.
Images (Click to enlarge)
Friday, October 29th, 2021 AT 5:22 PM