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DLC Diagnosis Or No Scan Tool Data

NOTE: Perform On-Board Diagnostic (OBD) system check after completing any repairs. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .
  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step.
  2. Turn ignition on, with engine off. Connect scan tool. If scan tool powers up, go to next step. If scan tool does not power up, go to step  5.
  3. Turn ignition off for 15 seconds. Immediately attempt to start engine. If engine is not cranked within 5 seconds after ignition is turned on, misdiagnosis could occur. If engine starts and then stalls after about 5 seconds, see appropriate BODY CONTROL MODULE article in ACCESSORIES & EQUIPMENT. If engine does not start and stall after about 5 seconds, go to next step.
  4. If engine cranks but does not start, go to step  9. If engine starts and continues to run, go to step  13.
  5. Disconnect scan tool. Turn ignition on, with engine off. Using a test light connected to ground, probe battery positive feed circuit at DLC. See WIRING DIAGRAMS article. If test light illuminates, go to next step. If test light does not illuminate, go to step  16.
  6. Using a test light connected to battery positive, probe both ground circuits at DLC. See WIRING DIAGRAMS article. If test light illuminates for both circuits, go to next step. If test light does not illuminate for both circuits, go to step  8.
  7. Inspect scan tool connections at DLC. Also, inspect DLC terminals for proper tension. Repair as necessary.
  8. Repair open in ground circuits to DLC.
  9. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Using a test light connected to battery ground, probe all PCM battery and PCM ignition feed circuits at PCM harness connectors. See WIRING DIAGRAMS article. If test light illuminates for each circuit, go to next step. If test light does not illuminate for each circuit, go to step  14.
  10. Using DVOM, check resistance between battery ground and PCM ground circuits at PCM harness connectors. See WIRING DIAGRAMS article. If resistance is equal to or less than 2 ohms for each circuit, go to next step. If resistance is not less than 5 ohms for each circuit, go to step  15.
  11. Check PCM for proper connections. Repair as necessary. If connections are okay, go to next step.
  12. Replace PCM. Perform PCM relearn procedures.
  13. Repair open in class 2 serial data circuit between splice pack and PCM.
  14. Repair circuit that did not illuminate test light.
  15. Repair faulty PCM ground circuits.
  16. Repair faulty battery positive feed circuit.
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