LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2007 >> RL >> Repair and Diagnosis >> External Pages >> Different car >> Section 45 (Multiplex Integrated Control System) >> MICU Input Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

MICU Input Test

WARNING: This page is about a different car, the 2008 Acura TL and 2007 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Make sure the ignition switch is OFF before troubleshooting the under-dash fuse/relay box connectors.
  1. Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
  2. Disconnect under-dash fuse/relay box connectors D, E, F, G, H, J, K, M, N, P, W, and X.
    NOTE: All connectors are shown from wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors Terminals
    G05462620Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. 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.
  4. With the connectors still disconnected, make these input tests at the connectors.
    • 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.
      WIRE TEST CONDITION CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      D11 BLU Under-hood fuse/relay box connector K (10P) disconnected Check for continuity between D11 terminal and under-hood fuse/relay box connector K (10P) No. 7 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      G1 PNK Power seat control unit connector A (20P) and AcuraLink control unit connector C (16P) disconnected Check for continuity between G1 terminal and power seat control unit connector A (20P) No. 14 terminal, G1 terminal and AcuraLink control unit (XM receiver) C (16P) No. 5 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      J4 BRN/BLK Door multiplex control unit connector A (22P) disconnected Check for continuity between J4 terminal and door multiplex control unit connector A (22P) No. 5 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      N22 LT BLU Display panel control unit connector A (22P) disconnected Check for continuity between N22 terminal and display panel control unit connector A (22P) No. 22 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      N28 BRN/YEL Gauge control module connector B (18P) disconnected Check for continuity between N28 terminal and gauge control module connector B (18P) No. 11 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      X18 WHT HandsFreeLink control unit connector (28P) disconnected Check for continuity between X18 terminal and HandsFreeLink control unit connector (28P) No. 19 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
      X27 LT GRN Combination switch control unit connector (8P) and automatic lighting control unit connector (14P) disconnected Check for continuity between X27 terminal and combination switch control unit connector (8P) No. 4 terminal, X27 terminal and automatic lighting control unit connector No. 4 terminal: There should be continuity. An open in the wire
      Check for continuity to ground: There should be no continuity. A short to ground in the wire
  5. Reconnect the connectors to the under-dash fuse/relay box, and make sure these input tests at the appropriate connectors on the 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 multiplex integrated control unit must be faulty. Replace the under-dash fuse/ relay box.
      WIRE TEST CONDITION CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      P7 RED Under all conditions Attach to ground: The ignition key light should come on.
      • Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box
      • Faulty LED
      • A short to ground in the wire
      • An open in the wire
      W4 GRN/RED Interior light switch in the middle position, all doors closed Attach to ground: The individual map lights should come on.
      • Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box
      • Faulty map light
      • An open in the wire
      D6
      F1
      X34      		 YEL Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
      • Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box
      • A short to ground in the wire
      • An open in the wire
      K5
      X35      		 WHT/RED Under all conditions Measure the voltage to ground: There should be battery voltage.
      • Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box
      • A short to ground in the wire
      • An open in the wire
      F8 YEL/GRN Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
      • Blown No. 20 (15 A) fuse in the under-dash fuse/relay box
      • A short to ground in the wire
      • An open in the wire
      X24 GRN/WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
      • Blown No. 27 (30 A) fuse in the under-dash fuse/relay box
      • A short to ground in the wire
      • An open in the wire
      E9
      H9      		 BLK Under all conditions Measure the voltage to ground: There should be less than 0.5 V.
      • Poor ground (G503, G601)
      • An open in the wire
      P1 BLK Under all conditions Measure the voltage to ground: There should be less than 0.5 V.
      • Poor ground (G502)
      • An open in the wire
scientia non olet · About LEMON Manuals