Cruise control turns on and sets properly.....at times works flawlessly, and at times shuts itself off after a few minutes. Able to immediately "resume" and it engages again just to turn itself off again a few minutes later. It does t not appear to be brake pedal position because I can hold pedal "up" and it still does it and I can actually puch pedal down slightly and keep cruise engaged. Is this the Speed sensor causing the issue (vehicle speedometer does not seem affected) or the Cruise Module, or anything else.

 

Welcome to the forum
The thing that stands out most to me as the easiest to check is " Inspect for proper operation of the stop lamps."
I'd pull the lamps out and clean and re-seat them in the sockets, make sure the elements are not intermittent, heck at 5+ years old you could probably just replace the stop lamps for good measure...


Service Information
2007 Chevrolet Uplander | Montana SV6, Terraza, Uplander (VIN U/V/X)Service Manual | Document ID: 1809088
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Cruise Control Inoperative/Malfunctioning
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description
The cruise control switch is an input to the engine control module (ECM), while the cruise cancel switch is an input to the body control module (BCM). The ECM monitors the cruise control on/off, set/coast, and the resume/accelerate switch signal circuits in order to detect when a cruise control function switch has been activated. The ECM detects a predetermined voltage signal when a cruise control function switch is applied, with each switch having a different voltage value.

The BCM monitors the cruise cancel switch in order to detect when the cancel switch has been activated. The BCM sends a class 2 message to the ECM regarding the status of the cruise cancel switch.

Conditions for Enabling Cruise Control
• The vehicle speed is greater than 40 km/h (25 mph).

• The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.

• The system voltage is within 9-16 volts.

• The park brake or brakes are not applied.

Diagnostic Aids
In order to avoid misdiagnosis, inspect for the following:

• Ensure that the following cruise control switches are not stuck in the engaged position:

- On/Off switch

- Set/Coast switch

- Resume/Accel switch

- Cancel switch

• Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation .

• Inspect for proper operation of the TAC module. Refer to Throttle Actuator Control (TAC) System Description .