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Home >> Acura >> 1999 >> 3.2TL >> Repair and Diagnosis >> Transmission >> Automatic Trans >> A/T Interlock System >> Shift Lock System Circuit Troubleshooting
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Shift Lock System Circuit Troubleshooting

  1. Press the brake pedal.

    Are the brake lights ON? 

    1. YES  - Go to step  2 .
    2. NO  - Repair faulty brake light circuit.
  2. Turn the ignition switch ON (II), and shift to the [P  ] position.
  3. Press the brake pedal, and release the accelerator pedal.
  4. Measure the voltage between PCM connector terminal A28 and body ground.
    Fig 1: Measuring The Voltage Between PCM Connector Terminal A28 And Body Ground
    G01159998

    Is there battery voltage? 

    1. YES  -Check for an open in the wire between the A 28 terminal and the multiplex control unit (driver's), and check for loose terminal fit in the multiplex control unit (driver's) connectors. If necessary, substitute a known-good multiplex control unit (driver's) and recheck.
    2. NO  -Go to step  5 .
  5. Turn the ignition switch OFF.
  6. Disconnect the A (32P) and B (25P) connectors from the PCM.
  7. Press the brake pedal and measure the voltage between PCM connector terminals A32 and B20 or B22.
    Fig 2: Measuring The Voltage Between PCM Connector Terminals A32 and B20 or B22
    G01159999

    Is there battery voltage? 

    1. YES  -Release the brake pedal, and go to step  8 .
    2. NO  -Repair open in the wire between PCM connector terminal A32 and the brake switch.
  8. Reconnect the A (32P) and B (25P) connectors to the PCM.
  9. Turn the ignition switch ON (II).
  10. Measure the voltage between PCM connector terminals C27 and B20 or B22.
    Fig 3: Measuring Voltage Between PCM Connector Terminals C27 and B20 or B22
    G01160000

    Is there about 0.5 V (throttle fully closed)? 

    1. YES  -Go to step  15 .
    2. NO  -Go to step  11 .
  11. Turn the ignition switch OFF.
  12. Disconnect the throttle position sensor connector.
  13. Measure the voltage between the No. 1 and No. 3 terminal of the throttle position sensor connector.
    Fig 4: Measuring Voltage Between No. 1 & No. 3 Terminal
    G01160001

    Is there about 5V? 

    1. YES  -Check for short or open in the wire between PCM connector terminal C27 and the TPS. If the wire is OK, replace the TPS.
    2. NO  -Go to step  14 .
  14. Turn the ignition switch OFF, and disconnect the PCM connector. Check for continuity between the No. 1 terminal and body ground, and between the No. 3 terminal and body ground.
    Fig 5: Checking For Continuity Between No. 1 Terminal And Body Ground
    G01160002

    Is there continuity? 

    1. YES  -Check for a short to ground between the No. 3 terminal of the TPS connector and ground. If the wire is OK, replace the PCM.
    2. NO  -Go to step  15 .
  15. Disconnect the shift lock solenoid connector.
  16. Check for continuity between the No. 2 terminal of the shift lock solenoid connector and the No. 22 terminal of the multiplex control unit (driver's) connector B (22P).
    Fig 6: Checking For Continuity Between The No. 2 Terminal Of The Shift Lock Solenoid Connector & The No. 22 Terminal Of The Multiplex Control Unit (Driver's) Connector B (22P)
    G01160003

    Is there battery voltage? 

    1. YES  -Go to step  17 .
    2. NO  -Repair open in the wire between the No. 22 terminal of the multiplex control unit (driver's) connector B (22P) and the shift lock solenoid.
  17. Turn the ignition switch ON (II).
  18. Measure the voltage between the No. 1 terminal of the shift lock solenoid connector and body ground.
    Fig 7: Measuring Voltage Between The No. 1 Terminal, Shift Lock Solenoid Connector & Body Ground
    G01160004

    Is there battery voltage? 

    1. YES  -Go to step  19 .
    2. NO  -Check for blown No. 8 (7.5 A) fuse in the driver's under-dash fuse/relay box. If the fuse is OK, repair open or short in the wire between the No. 1 terminal of the shift lock solenoid and the driver's under-dash fuse/relay box.
  19. Connect the No. 1 terminal of the shift lock solenoid connector to the battery positive terminal, and connect the No. 2 terminal to the battery negative terminal.
    NOTE: Do not connect the No. 2 terminal to the battery positive terminal or you will damage the diode inside the shift lock solenoid.
  20. Check that the shift lock solenoid operates.
    Fig 8: Identifying Shift Lock Solenoid Connector
    G01160005

    Does the shift lock solenoid operate properly? 

    1. YES  -Check for a loose multiplex control unit (driver's) connector. If necessary, substitute a known-good multiplex control unit (driver's) and recheck.
    2. NO  -Replace the shift lock solenoid.
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