Impala V8-5.3L (2008)
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If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions
Circuit/System Verification
1. Ignition ON, perform the scan tool IPC Display Test. Verify the cruise control indicator illuminates.
‹› If the indicator does not illuminate, replace the IPC.
2. Replace the ECM/PCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
Cruise Control Malfunction
Cruise Control Malfunction
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 switch signal circuit in order to detect
when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit
when a switch is applied.
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 are not applied.
Diagnostic Aids
Caution: Refer to Restraint System Service Precautions.
Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling.
In order to avoid misdiagnosis, inspect for the following:
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Verify there are no DTCs set as current. If any DTCs are set as current, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the
appropriate diagnostics/repairs before proceeding with symptom based diagnostics. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions
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Inspect the cruise control switches for any sticking or binding conditions.
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Inspect for proper operation of the stop lamps.
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With the ignition ON, rotate the steering wheel to both steering stops while activating each cruise control switch separately. With a scan tool,
observe all cruise control switch parameters in the ECM. Ensure that each cruise control switch activated and that each displayed switch position
parameters do not match or reads Error, this will aid in locating an intermittent fault within the inflatable restraint steering wheel module coil.
Circuit/System Verification
Ignition ON, cruise on/off switch ON. With a scan tool, observe the Cruise Control Switch parameter in the BCM. Verify that the Cruise Control Switch
parameter changes to match accordingly for each switch as it is activated and released. Road test the vehicle to ensure the cruise control system functions
as described in Cruise Control Description and Operation.
Circuit/System Testing
