PRE-RELEASE
Diagnostic System Check - Vehicle
Diagnostic System Check - Vehicle |
Diagnostic Instructions |
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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• |
Diagnostic System Check Instructions
provides an overview of each diagnostic step.
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Continue through the Diagnostic System Check until you are directed to follow a particular diagnostic or repair procedure. Once a repair has been completed, perform the
Diagnostic Repair Verification
and verify the customer concern has been corrected.
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The diagnostic procedures within this manual are developed on the assumption that the following areas function as designed:
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The 12V battery is fully charged and cables are clean and tight. Refer to
Battery Inspection/Test
.
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Fuses are not open. Refer to
Power Distribution Schematics
and
Electrical Center Identification Views
.
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Ground circuits for the area of customer concern are clean, tight, and in the correct location. Refer to
Ground Distribution Schematics
and
Harness Routing Views
.
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All connections/connectors for the area of concern are fully seated. Refer to
Component Connector End Views
.
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There are no aftermarket devices that affect the operation of the system. Refer to
Checking Aftermarket Accessories
.
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The scan tool powers up. Refer to
Scan Tool Does Not Power Up
.
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Diagnostic System Check |
1. |
VERIFY CUSTOMER CONCERN-Understand and validate the customer concern. Inspect the visible system components for obvious damage or conditions that may cause the concern.
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2. |
BULLETIN SEARCH-Check for related bulletins, recall/field actions and preliminary information.
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3. |
MECHANICAL CONCERNS-Verify the symptom is not exclusively a mechanical concern.
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4. |
If the symptom is exclusively a mechanical concern, refer to
Symptoms - Vehicle
.
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5. |
VEHICLE POWER UP VERIFICATION-Ignition ON, verify the vehicle powers up.
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6. |
If the vehicle does not power up, refer to
Power Mode Mismatch
.
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7. |
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: |
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Any control module that is not communicating.
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Any DTC, including symptom byte, and the control module that has set the DTC.
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8. |
If the scan tool does not communicate with any control module on the vehicle, refer to
Data Link References
.
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9. |
CONTROL MODULE INTERNAL PERFORMANCE FAULTS-Verify there are no current control module Internal Hardware Performance DTCs set.
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10. |
If any DTC of this type is set, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
.
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11. |
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.
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12. |
If the scan tool does not communicate with one or more control modules refer to
Data Link References
.
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13. |
COMMUNICATION and POWERMODE FAULTS-Verify there are no current control module Power Mode or Communication DTCs set.
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14. |
If any DTC of this type is set, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
.
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15. |
POWER MODE VERIFICATION-Driver door open, observe the scan tool Power Mode parameter while cycling the ignition switch through all the power modes. Verify the current Power Mode parameter matches the actual ignition switch positions. |
16. |
If the Power Mode parameter does not match the actual ignition switch positions, refer to
Power Mode Mismatch
.
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17. |
ENGINE CRANK and RUN VERIFICATION-Verify that the engine cranks and runs.
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18. |
If the engine does not crank, refer to
Engine Does Not Crank
.
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19. |
If the engine does not run, refer to
Engine Cranks But Does Not Run (LAU)
Engine Cranks But Does Not Run (LF1)
.
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20. |
REMAINING DTC REVIEW-Verify there are no other DTCs set.
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21. |
If other DTCs are set, diagnose them in the order listed below. Refer to
Diagnostic Trouble Code (DTC) List - Vehicle
.
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21.1. |
Voltage DTCs
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21.2. |
Programming, Setup, Configuration or Software Performance DTCs
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21.3. |
Component related DTCs
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21.4. |
System related DTCs
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21.5. |
Any remaining DTCs
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22. |
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.
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23. |
If the customer concern is related to inspection/maintenance testing, refer to
Inspection/Maintenance System Check
.
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24. |
SYMPTOM DIAGNOSIS-Diagnose any remaining customer concern. Refer to
Symptoms - Vehicle
.
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