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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 65 (Automatic Transmission Diagnosis - 4L60-E) >> Symptom Tests >> 2ND Gear Start Switch Indicator Light - Always On Or Inoperative >> Diagnostic Procedure

Diagnostic Procedure

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  1. Connect scan tool to DLC. Turn ignition on, engine off. While monitoring 2nd gear start switch parameter on scan tool, cycle 2nd gear start switch. If scan tool displays YES when switch is first pressed, and then NO when pressed a second time, go to step  6. If scan tool display is not as specified, go to next step.
  2. Disconnect 2nd gear start switch harness connector from switch. Measure voltage between ground and terminal "E" (signal circuit) at 2nd gear start switch harness connector. If voltage is 10-12 volts, go to next step. If voltage is not 10-12 volts, go to step  5.
  3. Connect fused jumper wire between terminals "E" and "F" of 2nd gear start switch harness connector. See WIRING DIAGRAMS . While monitoring scan tool, connect and disconnect jumper wire from terminal "F". If scan tool status changes between YES and NO, go to step  15. If scan tool status does not change between YES and NO, go to next step.
  4. Check for open in 2nd gear start switch ground circuit. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  16.
  5. Check 2nd gear start switch signal circuit for open or short to ground. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  16.
  6. If 2nd gear start switch indicator light illuminates when switch is first depressed, and then turns off when switch is pressed a second time, system is okay. If indicator light does not operate as specified, go to next step.
  7. If indicator light is illuminated at all times, go to step  13. If indicator light is not illuminated at all times, go to next step.
  8. Using test light connected to ground, probe terminal "B" (ignition feed circuit) at 2nd gear start switch harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step  10.
  9. Using test light connected to ground, probe terminal "A" (control circuit) at 2nd gear start switch harness connector. If test light illuminates, go to step  14. If test light does not illuminate, go to step  15.
  10. Check condition of 2nd gear start switch circuit fuse. See WIRING DIAGRAMS . If fuse is open, go to next step. If fuse is okay, go to step  12.
  11. Check 2nd gear start switch ignition feed circuit for short to ground. Repair as necessary. After repairs, go to step  17.
  12. Check for open in 2nd gear start switch ignition feed circuit. Repair as necessary. After repairs, go to step  17.
  13. Check 2nd gear start switch control circuit for short to ground. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  16.
  14. Check for open in 2nd gear start switch control circuit. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  16.
  15. Replace 2nd gear start switch. After repairs, go to step  17.
  16. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
  17. Monitor 2nd gear start switch parameter on scan tool, and indicator light. If ON is displayed first time switch is depressed and indicator light illuminates, and OFF is displayed second time switch is depressed and indicator light turns off, system is okay. If operation is not as specified, go to step  1.
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