Cruise Control Shuts Off When the Hazards Are Switched On - keywords bulb CHMSL inoperative light lamp stop switch T43

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

The cruise control system shuts off or will not set when the hazard warning flashers are turned on.

This is normal operation for vehicles with the T43 Rear Spoiler option. No repair attempts should be made. Vehicles with this option use a light emitting diode style Center High Mounted Stop Lamp (CHMSL). When the Hazard Switch is depressed, the Stop Lamp Override switch, located inside the Turn Signal/Multifunction Switch, opens preventing current flow through the Turn Signal bulbs. When this happens, the Cruise Control Module senses an input on the Stop Lamp Switch Signal (circuit 17), and shuts the cruise control off. Vehicles without the T43 option do not operate in this manner because the CHMSL, on these vehicles, use incandescent bulbs allowing there to be enough resistance in circuit 17 to prevent the false input.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.