* Cruise control module: This is the brain of the system. It could be faulty, malfunctioning, or even just have a loose connection. This is a common culprit.
* Brake switch: The cruise control disengages automatically when you brake. A faulty brake switch can prevent the cruise control from working correctly, or even constantly disengage it.
* Clutch switch (if applicable): Manual transmission models will have a clutch switch. If the switch is faulty, it may prevent the cruise control from engaging.
* Speed sensor: The cruise control relies on the vehicle speed sensor to maintain speed. A faulty sensor will prevent it from functioning.
* Vacuum lines (if applicable): Older systems might use vacuum lines to actuate the throttle. A leak or blockage in these lines could prevent the cruise control from working.
* Wiring harness: Worn, damaged, or corroded wires in the harness can interrupt the signals needed for the cruise control to function. Check for breaks, especially near the steering column and under the hood.
* Steering wheel controls: The buttons on your steering wheel may be faulty or the connection to the module may be broken.
* Throttle position sensor (TPS): A faulty TPS can provide inaccurate information to the cruise control module, preventing it from working properly.
Troubleshooting Steps:
1. Check the brake switch: See if the brake lights illuminate when you press the brake pedal. If not, the brake switch is a likely suspect.
2. Inspect wiring: Look carefully at the wiring harness related to the cruise control system. Check for damage, corrosion, or loose connections. This will require some familiarity with automotive wiring.
3. Have it professionally diagnosed: The most reliable way to pinpoint the problem is to take your Cadillac to a qualified mechanic or auto electrician. They have diagnostic tools that can test the various components in the cruise control system. A code reader may show a relevant fault code.
Without further diagnostics, it's difficult to say precisely what's wrong. But checking the above areas, especially the cruise control module, brake switch, and wiring, should point you in the right direction. Remember safety first – don't attempt complex repairs unless you have the necessary knowledge and tools.
