2011 Acura MDXFACTORY OEM SERVICE PROCEDURE

Relay Control Module Input Test

NOTE: Before testing the relay control module, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A 
  1. Turn the ignition switch to LOCK (0).
  2. Remove the under-hood fuse/relay box DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE) ).
  3. Disconnect under-hood fuse/relay box connectors D (10P) and E (14P).
    Fig 1: Identifying Connectors D (10P) And E (14P)
    G08055191Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. 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 5.
  5. With the connectors still disconnected, do the following input tests:
    • 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 desired result is not obtained
    E1 LT GRN Under all conditions (Under-dash fuse/relay box connector D(17P) disconnected Check for continuity between terminal E1 and under-dash fuse/relay box connector D (17P) terminal No. 11:
    There should be continuity.    		 An open or high resistance in the wire
    Check for continuity to ground:
    There should be no continuity.    		 A short to ground in the wire
  6. Reconnect the connectors, and do the following input tests:
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, replace the relay control module.
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
D3 BLK In all ignition switch positions Measure the voltage to ground:
There should be less than 0.2 V.
  • Poor ground (G202) or an open in the ground wire
  • An open or high resistance in the wire
D4 BLK In all ignition switch positions Measure the voltage to ground:
There should be less than 0.2 V.
  • Poor ground (G401) or an open in the ground wire
  • An open or high resistance in the wire
D6 WHT Under all conditions Measure the voltage to ground:
There should be battery voltage.
  • Blown No. 4 (40 A) fuse in the main under-hood fuse box
  • Blown No. 7(10 A) fuse in the under-dash fuse/relay box
  • Faulty main under-hood fuse box
  • Faulty under-dash fuse/relay box
  • An open or high resistance in the wire
D7 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
  • Faulty under-dash fuse/relay box
  • An open or high resistance in the wire
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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