Lights-on, Key-in, Seat Belt Reminder and Key Light Timer Indicator Systems (Multiplex Integrated Control Unit) Input Test

1. Before testing, troubleshoot the multiplex integrated control system test mode A.

Multiplex Integrated Control Unit

1. Remove the left kick panel (LHD type) or right kick panel (RHD type).

1. Disconnect the under-dash fuse/relay box connectors F and P.
   NOTE: All connectors are wire side of female terminals.

1. Inspect the connector and socket terminals to be sure they are all making good contact.
   - If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
   - If the terminals are OK, go to Step 5 .

1. Reconnect the connectors, and make these input tests at the connector.
   - If any test indicates a problem, find and correct the cause, then recheck the system.
   - If all the input tests prove OK, go to Step 6 .

   Cavity | Wire | Test condition | Test: Desired result | Possible cause if result is not obtained
   --- | --- | --- | --- | ---
   F14 | BLU | Ignition switch ON (II), driver's seat belt is unbuckled. | Check for voltage to ground: There should be 1 V or less. |
   - Faulty driver's seat belt switch
   - Poor ground (G601)
   - An open in the wire
   Ignition switch ON (II), driver's seat belt is buckled. | Check for voltage to ground: There should be 5 V or more. |
   - Faulty driver's seat belt switch
   - Short to ground
   P13 *1 P2 *2 | RED/WHT | Ignition key in the ignition switch. | Check for voltage to ground: There should be 1 V or less. |
   - Faulty ignition switch
   - Poor ground (G501)
   - An open in the wire
   Ignition key out of the ignition switch. | Check for voltage to ground: There should be 5 V or more. |
   - Faulty ignition switch
   - Short to ground

   *1: | LHD type
   *2: | RHD type

1. Remove the gauge control module.

1. Disconnect the gauge control module 30P connector.

1. Inspect the connector and socket terminals to be sure they are all making good contact.
   - If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
   - If the terminals are OK, go to Step 9 .

1. With the connectors still disconnected, make these input tests at the connector.
   - If any test indicates a problem, find and correct the cause, then recheck the system.
   - If the input tests prove OK, go to Step 10 .

   Cavity | Wire | Test condition | Test: Desired result | Possible cause if result is not obtained
   --- | --- | --- | --- | ---
   B20 | BLK | Under all conditions | Check for continuity to ground: There should be continuity. |
   - Poor ground (G501, G506)
   - An open in the wire

1. Perform the gauge self test procedure.
   - If the beeper sounds and the seatbelt light flashes, go to Step 11 .
   - If the beeper does not sounds, or the seatbelt light does not flash, replace the gauge control module.

1. Substitute a known-good under-dash fuse/relay box and recheck the system.
   - It the symptom is gone, the MICU is faulty; replace the under-dash fuse/relay box.
   - It the symptom is still present, the gauge control module is faulty; replace the gauge control module.