FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Diagnostic System Check - Vehicle




Diagnostic System Check - Vehicle

Diagnostic Instructions

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic System Check Instructions Diagnostic System Check Instructions provides an overview of each diagnostic category.
* 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 Verification Tests and verify the customer concern has been corrected.

The diagnostic procedures within this manual are developed on the assumption that the following areas function as designed:

* The 12 V battery is fully charged and cables are clean and tight. Refer to Battery Inspection/Test Battery Inspection/Test.
* Fuses are not open. Refer to Power Distribution Schematics Power Distribution Schematics and Electrical Center Identification Views X50A Fuse Block - Underhood Label.
* Ground circuits for the area of customer concern are clean, tight, and in the correct location. Refer to Ground Distribution Schematics G101 and Harness Routing Views Front Fascia Harness Routing.
* All connections/connectors for the area of concern are fully seated. Refer to Component Connector End Views Hybrid/EV Battery Pack X1.
* There are no aftermarket devices that affect the operation of the system. Refer to Checking Aftermarket Accessories Checking Aftermarket Accessories.
* The scan tool powers up. Refer to Scan Tool Does Not Power Up Scan Tool Does Not Power Up.

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.
2. BULLETIN SEARCH - Check for related bulletins, recalls/field actions, and preliminary information.
3. MECHANICAL CONCERNS - Verify the symptom is not exclusively a mechanical concern.

If the symptom is exclusively a mechanical concern
Refer to Symptoms - Vehicle Symptoms - Vehicle.

If the symptom is not a mechanical concern

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.

4. 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 Power Mode Mismatch.

If the vehicle powers up

5. 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 Initial Inspection and Diagnostic Overview.

If the scan tool communicates with any control module

6. CONTROL MODULE INTERNAL PERFORMANCE FAULTS - Verify there is no current control module Internal Performance DTCs set.

If any DTC of this type is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

If no DTC of this type is set

7. CONTROL MODULE COMMUNICATION VERIFICATION - Verify the vehicle is not built with any control module listed as not communicating with the scan tool; refer to Data Link References Initial Inspection and Diagnostic Overview.

If the vehicle is built with a control module that is not communicating
Refer to Data Link References Initial Inspection and Diagnostic Overview.

If all control modules the vehicle is built with are communicating

8. 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 Diagnostic Trouble Code (DTC) List - Vehicle.

If no DTC of this type is set

Note: The electric propulsion system will be active in the vehicle ON state during this test. Ensure the vehicle is out of gear and the parking brake is applied. Turn the vehicle power mode to vehicle OFF as soon as the vehicle ON power mode parameter has been observed.

9. POWER MODE VERIFICATION - Driver door open, observe the scan tool Power Mode parameter while cycling the push button switch through all the power modes. Verify the current Power Mode parameter matches the actual vehicle power mode states.

If the Power Mode parameter does not match the vehicle power mode states
Refer to Power Mode Mismatch Power Mode Mismatch.

If the Power Mode parameter matches the vehicle power mode states

10. 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 Diagnostic Trouble Code (DTC) List - Vehicle.

1. Voltage DTCs
2. Programming, Setup or Configuration or Software Performance DTCs
3. Component related DTCs
4. System related DTCs
5. Any remaining DTCs

If no other DTCs are set

11. 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 Monitors, Trips, Drive Cycles and Readiness Codes.

If the customer concern is not related to inspection/maintenance testing

12. SYMPTOM DIAGNOSIS - Diagnose any remaining customer concern. Refer to Symptoms - Vehicle Symptoms - Vehicle.