Diagnostic System Check
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
- VERIFY CUSTOMER CONCERN - Understand and validate the customer concern. Inspect the visible system components for obvious damage or conditions that may cause the concern.
- BULLETIN SEARCH - Check for related bulletins, recall/field actions and preliminary information.
- MECHANICAL CONCERNS - Verify the symptom is not exclusively a mechanical concern.
- If the symptom is exclusively a mechanical concern
Refer to Symptoms - Vehicle .
- Go to next step: If the symptom is not a mechanical concern
- If the symptom is exclusively a mechanical concern
- VEHICLE POWER UP VERIFICATION - Vehicle in Service Mode, verify the vehicle powers up.
- If the vehicle does not power up
Refer to Power Mode Mismatch .
- Go to next step: If the vehicle powers up
- If the vehicle does not power up
- CONTROL MODULE COMMUNICATION and DTC CHECK - Using a scan tool, perform the Vehicle DTC Information function and verify at least one control module communicates with the scan tool. Record on the Repair Order the following information:
- Any control module that is not communicating.
- Any DTC, including symptom byte, and the control module that has set the DTC.
- If the scan tool does not communicate with any control module on the vehicle
Refer to Data Link References .
- Go to next step: If the scan tool communicates with any control module
- CONTROL MODULE INTERNAL PERFORMANCE FAULTS - Verify there are no current control module Internal Hardware Performance DTCs set.
- If any DTC of this type is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If no DTC of this type is set
- If any DTC of this type is set
- CONTROL MODULE COMMUNICATION VERIFICATION - Verify the vehicle is built with any control module listed as not communicating, refer to Data Link References
. All control modules should be communicating, as equipped.
- If the vehicle is built with a control module that is not communicating
Refer to Data Link References .
- Go to next step: If all control modules the vehicle is built with are communicating
- If the vehicle is built with a control module that is not communicating
- COMMUNICATION and POWERMODE FAULTS - Verify there are no current control module Power Mode or Communication DTCs set.
- If any DTC of this type is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If no DTC of this type is set
- If any DTC of this type is set
- POWER MODE VERIFICATION - Driver door open, observe each scan tool Power Mode data parameter while cycling through all power modes. Verify all Power Mode data parameters match the actual ignition switch/push button switch selection.
- If any Power Mode data parameter does not match
Refer to Power Mode Mismatch .
- Go to next step: If all Power Mode data parameters match
- If any Power Mode data parameter does not match
- PROACTIVE ALERT IDENTIFIERS - The technician is asked in this step to verify there are no Proactive Alert Identifiers set. These identifiers are displayed on the scan tool and will only appear when the OnStar subscription is active and the customer has opted into the Proactive Alert service.
- If any Proactive Alert Identifier is set
Refer to: Proactive Alerts List
- Go to next step: If no Proactive Alert Identifier is set
- If any Proactive Alert Identifier is set
- ENGINE CRANK and RUN VERIFICATION - Verify that the engine cranks and runs.
- If the engine does not crank
Refer to Engine Does Not Crank .
- If the engine does not run
Refer to Engine Cranks But Does Not Run .
- Go to next step: If the engine cranks and runs
- If the engine does not crank
- REMAINING DTC REVIEW - Verify there are no other DTCs set.
- If other DTCs are set
Diagnose them in the order listed below. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Voltage DTCs
- Programming, Setup or Configuration or Software Performance DTCs
- Component related DTCs
- System related DTCs
- Any remaining DTCs
- Go to next step: If no other DTCs are set
- If other DTCs are set
- EMISSION RELATED INSPECTION/MAINTENANCE TESTING CONCERNS - If inspection and maintenance checks are required in your region, verify the customer concern is not related to inspection/maintenance testing.
- If the customer concern is related to inspection/maintenance testing
Refer to Inspection/Maintenance System Check .
- Go to next step: If the customer concern is not related to inspection/maintenance testing
- If the customer concern is related to inspection/maintenance testing
- SYMPTOM DIAGNOSIS - Diagnose any remaining customer concern. Refer to Symptoms - Vehicle .
NOTE:
Do not clear any DTCs unless instructed to do so by a diagnostic procedure. If any DTC is Powertrain related, select Capture Info to store DTC and Freeze Frame/Failure Records to the scan tool.
NOTE:
The engine may start during this test. Ensure the vehicle is out of gear and the parking brake is applied. Turn the engine OFF as soon as the crank power mode parameter has been observed.