FixVault
Home › Infiniti › 2001 › Q45 Base › Repair and Diagnosis › Transmission › Automatic Trans › Shift Interlock Systems › Symptom Tests › Symptom No. 2 › Diagnostic Procedure

Diagnostic Procedure

  1. Access Shift Lock Control Unit (SLCU). See Figure . Ensure ignition is off. Measure voltage between SLCU harness connector terminal No. 1 and ground. See Figure . If battery voltage exists, go to next step. If battery voltage does not exist, check the following items and repair as necessary:
    • Check for open or short in circuit between SLCU harness connector terminal No. 1 and fuse No. 26 (20-amp).
    • Check for blown fuse No. 17 (10-amp).
  2. Turn ignition off. Measure voltage between SLCU harness connector terminal No. 5 and ground. See Figure . No voltage should exist. Turn ignition on, engine off. Battery voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, check the following items and repair as necessary:
    • Check for open or short in circuit between SLCU harness connector terminal No. 5 and battery.
    • Check for blown fuse No. 17 (10-amp).
    • Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.
  3. Turn ignition off. Disconnect SLCU harness connector. Check for continuity between SLCU harness connector terminal No. 7 and ground. See Figure . If continuity exists, go to next step. If continuity does not exist, repair open in circuit between SLCU harness connector terminal No. 7 and ground.
  4. Reconnect SLCU connector. Remove key from ignition switch. Access A/T device harness connector. See Figure . Measure voltage between A/T device harness connector terminal No. 5 and ground. See Figure . No voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, check key switch. See KEY SWITCH  under COMPONENT TESTS. Repair as necessary.
  5. Insert key into ignition switch. Measure voltage between A/T device harness connector terminal No. 5 and ground. See Figure . Battery voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, check the following items and repair as necessary:
    • Check for open or short in circuit between A/T device harness connector terminal No. 5 and key switch harness connector terminal No. 4.
    • Check for open or short in circuit between key switch harness connector terminal No. 3 and fuse No. 28 (10-amp) in junction block fuse block.
    • Check key switch. See KEY SWITCH  under COMPONENT TESTS.
  6. Turn ignition on, engine off. Ensure selector lever is in "P" position. Measure voltage between SLCU harness connector terminal No. 2 and ground. See Figure . No voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, check detention switch. See DETENTION SWITCH  under COMPONENT TESTS. Replace as necessary.
  7. Turn ignition on, engine off. Measure voltage between SLCU harness connector terminal No. 2 and ground while depressing brake pedal and selector lever button. See Figure . Battery voltage should exist. Move selector lever to any other position. Battery voltage should still exist. If voltage is as specified, go to next step. If voltage is not as specified, check the following items and repair as necessary:
    • Check for open or short in circuit between SLCU harness connector terminal No. 2 and A/T device harness connector terminal No. 7.
    • Check for open or short in circuit between A/T device harness connector terminal No. 5 and key switch harness connector terminal No. 4.
    • Check detention switch. See DETENTION SWITCH  under COMPONENT TESTS.
  8. Place selector lever in "P" position and release selector button. Turn ignition off. Access key lock solenoid. See Figure . Turn ignition on, engine off. Measure voltage between key lock solenoid harness connector terminal No. 2 and ground at the moment ignition is turned from off to on. See Figure . Battery voltage should exist for about 0.1 second. If voltage is as specified, go to next step. If voltage is not as specified, check for open or short between key lock solenoid harness connector terminal No. 2 and SLCU harness connector terminal No. 8. Repair as necessary. If harness is okay, replace SLCU.
  9. Turn ignition off. Disconnect key lock solenoid harness connector. Check for continuity between key lock solenoid harness connector terminal No. 1 and ground. See Figure . Continuity should exist. If continuity does not exist, repair open in circuit between key lock solenoid harness connector terminal No. 1 and ground.
About FixVault