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Remote Transmitter Inoperative

  1. Remove key from ignition switch. Ensure all doors are closed and locked. Turn wireless door lock buzzer switch to ON position (located on lower left side of instrument panel). Go to next step.
  2. While standing outside vehicle near driver's door, point transmitter toward vehicle. Press door LOCK button, and then UNLOCK button on transmitter for about one second. If doors do not lock and unlock properly, go to next step. If doors lock and unlock properly, system is okay at this time.
  3. Observe transmitter LED while pressing transmitter LOCK and UNLOCK buttons. If transmitter LED illuminates when transmitter LOCK and UNLOCK buttons are pressed, go to step  5. If transmitter LED does not illuminate when transmitter LOCK and UNLOCK buttons are pressed, go to next step.
  4. Replace transmitter battery. Check transmitter functions. If transmitter still does not operate properly, go to next step. If transmitter operates properly with new battery, system is okay.
  5. Remove key from ignition switch. Ensure all doors are closed and locked. Turn wireless door lock buzzer switch to ON position (located on lower left side of instrument panel). Go to next step.
  6. Perform the following within 35 seconds: insert key into ignition switch, and then remove it. Insert key once more. Turn ignition on, and then off one time within 5 seconds. Within 30 seconds, turn ignition on and off 9 additional times. Buzzer should produce a short chirp followed by a longer chirp, indicating successful entry into diagnostic mode. If buzzer chirps and system enters diagnostic mode as specified, go to next step. If system does not enter diagnostic mode regardless of buzzer operation, go to step  10.
  7. Press LOCK button on transmitter. Buzzer should produce a short chirp about every .5 second. Press UNLOCK button on transmitter. Buzzer should produce 2 short chirps about every .5 second. Press luggage compartment button on transmitter. Buzzer should produce a long chirp about every .5 second. If buzzer operation is as specified, go to next step. If buzzer produces a long continuous chirp, go to step  12. If buzzer does not produce any chirp, go to step  13.
  8. While standing about 3 feet from vehicle, press any transmitter button for 20 seconds (buzzer should chirp continuously), and then press button again. If buzzer operates as specified, other body control systems are at fault (transmitter and wireless door lock ECU are okay). See BODY CONTROL SYSTEMS - LS400 article. If buzzer does not operate as specified, go to next step.
  9. Transmitter or wireless door lock ECU is faulty. Repeat step  8 using a known-good transmitter. Replace original transmitter if necessary. If problem still exists, check wireless door lock ECU. See WIRELESS DOOR LOCK ECU RECEIVER CIRCUIT  under CIRCUIT TESTS. Repair as necessary.
  10. Repeat step  6, ensuring procedures are performed correctly. If buzzer operation is normal, but still does not enter diagnostic mode, go to next step. If buzzer still does not chirp, go to DOOR LOCK BUZZER DOES NOT CHIRP . Repair as necessary.
  11. Insert key into ignition switch. Using DVOM, check for continuity between ground and terminal No. 3 (Yellow wire) at body ECU harness connector "A". See WIRING DIAGRAMS . Continuity should be present. If continuity is not present, repair key unlock warning switch or circuit as necessary.
  12. Program transmitter. See PROGRAMMING . Retest system operation.
  13. Repeat step  7 using a known-good transmitter. If transmitter operates, replace original transmitter. If transmitter does not operate, go to next step.
    14. NOTE: The following step checks for wireless door lock signal error. For additional information on retrieving and diagnosing body ECU Diagnostic Trouble Codes (DTC), see MULTIPLEX CONTROL SYSTEMS - LS400 article.
  14. Using jumper wire, connect terminals Tc and E1 of DLC1 together. If DTC B1242/42 is present, repair short circuit in Brown/Red wire between terminal No. 4 of wireless door lock ECU and terminal No. 14 of body ECU harness connector "B". See WIRING DIAGRAMS . If DTC B1242/42 is not present, go to next step.
  15. Using DVOM, measure voltage between ground and terminal No. 14 (Brown/Red wire) at body ECU harness connector "B" without operating transmitter. See WIRING DIAGRAMS . If battery voltage is present, go to next step. If battery voltage is not present, repair open in Brown/Red wire.
  16. Remove key from ignition switch. Ensure all doors are closed and locked. Turn wireless door lock buzzer switch to ON position (located on lower left side of instrument panel). Using DVOM, measure voltage between ground and terminal No. 3 (Brown/White wire) at wireless door lock ECU. Voltage should be 4.5-5.5 volts. Voltage should be zero volts when transmitter is operated. If voltage is as specified, go to next step. If voltage is not as specified, repair open in Brown/White wire between terminal No. 3 of wireless door lock ECU and terminal No. 5 of body ECU harness connector "B".
  17. Using DVOM, measure voltage between ground and terminal No. 7 (Red wire) at wireless door lock ECU. See WIRING DIAGRAMS . Battery voltage should be present under all conditions. If voltage is as specified, go to next step. If voltage is not as specified, repair circuit between wireless door lock ECU and DOME fuse (10-amp) located in engine compartment junction block.
  18. Using DVOM, check for continuity between chassis ground and terminal No. 1 (White/Black wire) at wireless door lock ECU. See WIRING DIAGRAMS . If continuity is present, wireless door lock ECU is faulty. If continuity is not present, repair open or poor connection in White/Black wire.
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