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Home >> Chevrolet >> 2003 >> Tracker 2D Utility, RWD, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel Systems >> Fuel Pump Electrical Circuit Diagnosis >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK- ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 2.0L TRACKER article or DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 2.5L article. After performing diagnostic system check, go to next step.
  2. Remove fuel filler cap. Turn ignition on. Listen for fuel pump operation. Cycle ignition off and then on again if necessary. If fuel pump operates for about 2 seconds, go to next step. If fuel pump does not operate for about 2 seconds, go to step  4.
  3. Fuel pump electrical circuit is okay at this time. If fuel system pressure has not been checked, perform appropriate FUEL SYSTEM PRESSURE TEST under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 2.0L & 2.5L TRACKER. If fuel system pressure has been checked and is okay, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.0L & 2.5L TRACKER article.
  4. If fuel pump runs continuously with ignition on and engine off, go to step  17. If fuel pump does not run continuously with ignition on and engine off, go to next step.
    5. NOTE: In order to operate fuel pump with a scan tool, fuel level must be at least 20 percent and no DTCs set.
  5. Turn ignition off. Remove fuel pump relay. Using test light connected to battery positive, probe fuel pump relay control circuit at relay cavity No. 5. See Fig 1. Crank engine or use scan tool to command fuel pump on. If test light illuminates, turn ignition off and go to next step. If test light does not illuminate, go to step  16.
  6. Using test light connected to ground, probe fuel pump relay battery feed circuit (from main relay) at fuel pump relay cavity No. 1. Turn ignition on with engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step  11.
  7. Turn ignition off. Connect a fused jumper wire between fuel pump relay cavity No. 1 and fuel pump relay cavity No. 2. Turn ignition on. If fuel pump runs, go to step  14. If fuel pump does not run, go to next step.
  8. Leave fused jumper wire connected. Locate and disconnect Black 12-pin fuel pump in-line harness connector C401 located in floor harness to fuel pump harness inside frame rail. Using test light connected to ground, backprobe fuel pump power feed circuit at fuel pump in-line harness connector C401 (Pink/Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  12.
  9. Turn ignition off. Remove fused jumper wire from fuel pump relay cavities. Disconnect Black 12-pin fuel pump in-line harness connector C401. Using test light connected to battery positive, probe fuel pump ground circuit at fuel pump in-line harness connector C401 (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  13.
  10. Remove fuel tank. Check fuel pump wire harness between connector C401 and fuel pump assembly for open circuits. Remove fuel pump assembly. Check electrical connections and internal wire harness for damage. Repair as necessary. After repairs, go to step  24. If no problem is found, go to step  22.
  11. Check for open in battery feed circuit between main relay and fuel pump relay. Repair as necessary. After repairs, go to step  24. If circuit is okay, see MAIN RELAY CIRCUIT DIAGNOSIS (2.0L)  or MAIN RELAY CIRCUIT DIAGNOSIS (2.5L)  .
  12. Repair open or high resistance in fuel pump power feed circuit between fuel pump relay and fuel pump in-line harness connector C401. After repairs, go to step  24.
  13. Repair open or poor connection in fuel pump ground circuit between ground G400 and fuel pump in-line harness connector C401. After repairs, go to step  24.
  14. Turn ignition off. Remove fused jumper wire from fuel pump relay cavities. Turn ignition on. Using test light connected to ground, probe fuel pump relay ignition feed circuit (from IG fuse) at fuel pump relay cavity No. 3. See Fig 1. If test light illuminates, go to step  21. If test light does not illuminate, go to next step.
  15. Repair open or short in fuel pump relay ignition feed circuit. After repairs, go to step  24.
  16. Check for open in fuel pump relay control circuit between fuel pump relay and PCM. Repair as necessary. After repairs, go to step  24. If circuit is okay, go to step  23.
  17. Remove fuel pump relay. If fuel pump continues to run, go to next step. If fuel pump stops, leave fuel pump relay removed and go to step  19.
  18. Repair short to voltage in fuel pump power feed circuit. After repairs, go to step  24.
  19. Turn ignition off. Using test light connected to battery positive, probe fuel pump relay control circuit at relay cavity No. 4. See Fig 1. Turn ignition on and observe test light for 10 seconds. If test light remains illuminated for more than 3 seconds, go to next step. If test light does not remain illuminated for more than 3 seconds, go to step  21.
  20. Check for short to ground in fuel pump relay control circuit between fuel pump relay and PCM. Repair as necessary. After repairs, go to step  24. If circuit is okay, go to step  23.
  21. Replace fuel pump relay. After repairs, go to step  24.
  22. Replace fuel pump. After repairs, go to step  24.
  23. Replace PCM. Perform PCM relearn procedures. After repairs, go to next step.
  24. Operate vehicle under conditions which original symptom was noted. If system operates properly, system is okay. If system does not operate properly, see DIAGNOSTIC AIDS .
Fig 1: Identifying Fuel Pump Relay Harness Connector
G00117294Courtesy of GENERAL MOTORS CORP.
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