Sierra 1500 4WD V8-6.0L (2007)
Cruise Control: Symptom Related Diagnostic Procedures
Symptoms - Cruise Control
Symptoms - Cruise Control
Important: The following steps must be completed before using the symptom tables.
1. Perform the Diagnostic System Check - Vehicle, before using the Symptom Tables in order to verify that all of the following are true:
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There are no DTCs set.
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The control modules can communicate via the serial data link. See: Testing and Inspection/Initial Inspection and Diagnostic
Overview/Diagnostic System Check - Vehicle
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Cruise Control Description and Operation.
Visual/Physical Inspection
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Inspect for aftermarket devices which could affect the operation of the Cruise Control System.
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Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in
Diagnostic Aids. See: Testing and Inspection/Component Tests and General Diagnostics
Symptom List
Refer to Cruise Control Inoperative/Malfunctioning.
Cruise Control Inoperative/Malfunctioning
Cruise Control Inoperative/Malfunctioning
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection/Initial Inspection and
Diagnostic Overview/Diagnostic System Check - Vehicle
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Review Strategy Based Diagnosis for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate, and
cancel switch signal circuits in order to detect when a cruise control function switch has been activated. The BCM detects a predetermined voltage signal
when a cruise control function switch is applied, with each switch having a different voltage value.
Conditions for Enabling Cruise Control
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The vehicle speed is greater than 40 km/h (25 mph).
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The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
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The system voltage is within 9-16 volts.
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The park brake or brakes is not applied.
Diagnostic Aids
Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.
In order to avoid misdiagnosis, inspect for the following:
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Ensure that the following cruise control switches are not stuck in the engaged position:
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On/Off switch
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- SET switch
