How to Troubleshoot the MICU
NOTE: Use only if the HDS is unavailable.
System Description

Test Mode 1

The B-CAN communication line can be checked by the Test Mode 1, and the ceiling light indicates a DTC with the blinking pattern.

Test Mode 2

Test Mode 2 can check the switch and sensor circuits connected to the MICU. Some switch and sensor circuits connected to the gauge control module (tach) and immobilizer-keyless control unit can check also when the B-CAN line is normal.
Test Mode 1
Special Tools Required
  1. Check the No. 16 (15 A) fuse in the under-hood fuse/relay box and the No. 10 (7.5 A) fuse in the under-dash fuse/relay box. If the fuse is blown, find and correct the cause, then replace the fuse.
  1. Turn the ceiling light switch in ‘‘DOOR'' (middle) position. Close all doors. Turn the ignition switch to ON (II).
    NOTE: If the driver's seat belt is unbuckled, the beeper will beep.
  1. Connect the MPCS short connector (A) to the MICU service check connector (B), and turn the switch (C) on.
  1. After 5 seconds, the ceiling light should come on for 2 seconds, go out, then blink once for 0.2 second. This means that you are in Test Mode 1 of the self-diagnostic function.
  1. About 1 second after step 5, the ceiling light will blink and indicate the DTC, and repeat it every 3 seconds. Troubleshoot the DTC as indicated below:
    DTC
    Cause and Troubleshooting
    1
    The MICU cannot receive signals sent from the MICU itself (for checking the sending signals), or the MICU cannot receive signals from the gauge control module (tach). If DTC 1 only indicates, substitute a known-good gauge control module (tach) and an MICU one at a time, in that order, and recheck for the DTC after each substitution.

How to cancel the Test Mode 1
NOTE: To cancel Test Mode 1, turn off the MICU short connector switch for more than 10 seconds or turn the ignition switch to LOCK (0).
Test Mode 2
  1. While in Test Mode 1, turn off the MPCS short connector switch (A) for about 5 to 10 seconds, then turn it on again.
  1. The ceiling light should come on for 2 seconds, go out, then blinks twice more at 0.2 second intervals. This means the system has gone from Test Mode 1 to Test Mode 2.
  1. While still in Test Mode 2, operate the switches in the table below. If the circuit is OK, the ceiling light blinks once. If the circuit is faulty, the ceiling light does not blink.
    • If the ceiling light does not blink even a switch is operated, check two or three other circuits listed in the table. If the ceiling light blinks for each circuit, the additional circuits are OK, repair the short or open circuit that failed the test in Step 3 .
    • If the ceiling light does not blink again, this multiple failed circuits mean that the control unit has failed without triggering a DTC. Test a few more circuits. If they also fail, test the MICU input test, or the gauge control module self-diagnosis function. If all the tests prove OK, substitute a known-good MICU or gauge control module (tach) one at a time, then recheck. If the system works properly, the part that was substituted is faulty; replace it.
    Driver's door lock switch (UNLOCK)
    Windshield wiper MIST switch
    Driver's door lock switch (LOCK)
    Windshield washer switch
    Driver's door lock knob switch (UNLOCK)
    Windshield wiper intermittent dwell time controller
    Driver's door lock knob switch (LOCK)
    Turn signal switch (LEFT)
    Driver's door key cylinder switch (UNLOCK)
    Turn signal switch (RIGHT)
    Driver's door key cylinder switch (LOCK)
    Hazard warning switch
    Passenger's door lock switch (UNLOCK)
    Headlight switch (ON)
    Passenger's door lock switch (LOCK)
    Headlight switch (OFF)
    Passenger's door lock knob switch (UNLOCK)
    Headlight switch (SMALL)
    Driver's door switch
    Dimmer switch
    Passenger's door switch
    Passing switch
    Driver's walk-in switch
    Hood switch (with security)
    Passenger's walk-in switch
    Brake pedal position switch
    Audio switch
    Tailgate outer handle switch
    Windshield wiper HI/LO switch
    Tailgate latch switch
    Windshield wiper INT/LO switch
    Front fog light switch
    Rear fog light switch
    Ignition key switch
    Parking brake switch
    Headlight washer switch
    A/C switch

How to cancel the Test Mode 2
NOTE: To cancel Test Mode 2, turn off the MPCS short connector from the multiplex control inspection connector for more than 10 seconds or turn the ignition switch to LOCK (0).