SureTrack community member aph915 had a truck in their shop where the cruise control was inoperative and the cruise indicator light in the dash didn’t illuminate as expected. They posed the question to the community, and with the help of fellow community member ericsautomotive and others, they were able to resolve the issue.
The following Real Fix summarizes the interaction between them in the community that led to the solution.
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2002 GMC Yukon XL K1500 5.3
Cruise Control Inoperative, Replaced Bulbs
Customer complained that the cruise control was inoperative. Further investigation determined that the cruise indicator light was not illuminating as expected.
Diagnostic Steps Performed/Parts Replaced
Checked for DTCs and found none. PCM shows cruise control inhibited-yes. Have checked switch functions at cruise control module and all work and powers and grounds are good. Performed service manual test for cruise control inoperative and came to replacing PCM. Replaced PCM and cruise is still inoperative. Speedometer working correctly. All brake lights working. Cannot determine cause of cruise control inhibit.
Best Answer from Community
Backprobe power and ground supplies to the cruise control servo. Are they all present and the right voltage levels?.
Member Name: ericsautomotive
Found that the almost 5 volt signal at the cruise control servo was caused by customer installed LED brake light bulbs.
Replaced brake light bulbs with conventional bulbs and the 5 volts went away and the cruise control started working
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