LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2006 >> Ridgeline RT >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Multiplex Integrated Control System >> MICU Input Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

MICU Input Test

NOTE: Make sure the ignition switch is OFF before troubleshooting the under-dash fuse/relay box connectors.
  1. Before troubleshooting the multiplex integrated control system, troubleshoot the B-CAN System Diagnosis Test mode A (see Troubleshooting - B-CAN System Diagnosis Test Mode A ).
  2. Turn the ignition switch OFF.
  3. Remove the left front door sill trim and left side kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
  4. Disconnect the under-dash fuse/relay box connectors.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: View Of Connector Terminals
    G03691057Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 2: Identifying Connectors Location
    G03691058Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. 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 look OK, go to step 4.
  6. With the connectors still disconnected from the under-dash fuse/relay box, make these input tests at the connector(s).
    • 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 5.
      TEST CONDITION (1 OF 6)

      Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
      P7 WHT/BLK Under all conditions Attach to ground:
      The ignition key light should come on.
      • Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box
      • Faulty LED
      • An open in the wire
      W4 BLU/RED Interior lights switch in the middle position, all doors closed Attach to ground:
      The individual map lights should come on.
      • Blown No. 6 (10 A) fuse in the under-dash fuse/relay box
      • Faulty map light
      • An open in the wire
      D11 BLU Under all conditions Check for continuity between the D11 terminal and the relay control module connector J (10P) No. 8 terminal:
      There should be continuity.      		 An open in the wire
      Relay control module connector J (10P) disconnected Check for continuity to ground:
      There should be no continuity.      		 Short to ground
      J4 BRN/BLK Under all conditions Check for continuity between the J4 terminal and the power window master switch connector (23P) No. 16 terminal:
      There should be continuity.      		 An open in the wire
      Power window master switch (Door multiplex control unit) connector (23P) disconnected Check for continuity to ground:
      There should be no continuity.      		 Short to ground
      N22 LTBLU Under all conditions Check for continuity between the N22 terminal and the HVAC control unit connector (30P) No. 11 terminal (or climate control unit) connector (30P) No. 30 terminal:
      There should be continuity.      		 An open in the wire
      HVAC control unit (or climate control unit) connector (30P) disconnected Check for continuity to ground:
      There should be no continuity.      		 Short to ground
      N28 BRN/YEL Under all conditions Check for continuity between the N28 terminal and the gauge control module connector B (14P) No. 6 terminal:
      There should be continuity.      		 An open in the wire
      Gauge control module connector B (14P) disconnected Check for continuity to ground:
      There should be no continuity.      		 Short to ground
      X27 LT GRN Under all conditions Check for continuity between the X27 terminal and the combination switch connector (12P) No. 3 terminal:
      There should be continuity.      		 An open in the wire
      Combination switch connector (12P) disconnected Check for continuity to ground:
      There should be no continuity.      		 Short to ground
  7. Reconnect the connectors to the driver's under-dash fuse/relay box, and make sure these input tests at the appropriate connectors on the driver's under-dash fuse/relay box.
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, the MICU must be faulty, replace the driver's under-dash fuse/relay box assembly.
      TEST CONDITION (2 OF 6)

      Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
      E9
      H9      		 BLK Under all conditions Check for continuity to ground:
      There should be continuity.
      • Poor ground (G501)
      • An open in the wire
      P1 BLK Under all conditions Check for continuity to ground:
      There should be continuity.
      • Poor ground (G403)
      • An open in the wire
      D6
      J9
      X34      		 YEL Ignition switch ON (II) Check for voltage to ground:
      There should be battery voltage.
      • Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box
      • An open in the wire
      K5
      X35      		 WHT/RED Under all conditions Check for voltage to ground:
      There should be battery voltage.
      • Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box
      • An open in the wire
scientia non olet · About LEMON Manuals