Diagnostic Aids
Ensure that the correct application (model line, car year, etc.) has been selected on the scan tool. If communication still cannot be established, try the scan tool on another vehicle to ensure that the scan tool or cables are not the cause of the condition.
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation.
Any circuitry that is suspected of causing an intermittent complaint should be thoroughly checked for the following conditions:
- Backed-out terminals.
- Improper mating of terminals.
- Broken locks.
- Improperly formed or damaged terminals.
- Poor terminal-to-wiring connection.
- Physical damage to the wiring harness.
- Corrosion.
DATA LINK CONNECTOR DIAGNOSIS - DIAGNOSIS PROCEDURE
| Step | Action | Value (s) | Yes | No |
|---|---|---|---|---|
| 1 | Perform an ON-BOARD DIAGNOSTIC (OBD II) SYSTEM CHECK . Was the check performed? |
- | Go to Step 2. | Go to ON-BOARD DIAGNOSTIC (OBD II) SYSTEM CHECK . |
| 2 | With a test light connected to the ground, probe the Data Link Connector (DLC) battery feed terminal 16. Is the test light illuminate? |
- | Go to Step 4. | Go to Step 3. |
| 3 | Repair an open or short to ground in the DLC battery feed circuit. Is the repair complete? |
- | Go to Step 4. | - |
| 4 | With a test light connected to the battery, probe the DLC ground terminal 4 and 5. Is the test light illuminate? |
- | Go to Step 6. | Go to Step 5. |
| 5 | Repair an open circuit. Is the repair complete? |
- | Go to Step 6. | - |
| 6 |
Does the scan tool power up? |
- | Go to Step 8. | Go to Step 7. |
| 7 | Check for damages in the terminal of DLC and scan tool, and repair as needed. Is the repair complete? |
- | Go to Step 8. | - |
| 8 | Using a scan tool, request engine data of Engine Control Module (ECM). Does the scan tool display any data? |
- | Go to Step 12. | Go to Step 9. |
| 9 | Install the scan tool on another vehicle and check for proper operation. Does the scan tool work properly on a different vehicle? |
- | Go to Step 11. | Go to Step 10. |
| 10 | The scan tool is malfunctioning. Refer to the scan tool's manual for repair. Is the repair complete? |
- | Go to Step 12. | - |
| 11 | Repair communication circuit between the ECM and DLC. Is the repair complete? |
- | Go to Step 12. | - |
| 12 |
Does the engine and continue to run? |
- | Go to Step 13. | Go to Step 2. |
| 13 |
Are any DTCs displayed that have not been diagnosed? |
- | Go to applicable DTC Table . | System OK |