2015 Acura MDX BaseFACTORY OEM SERVICE PROCEDURE

Second Row Seat Heater Control Unit Input Test (2014 2015)

NOTE:

Before testing, check the No. B3-3 (60 A) fuse in the main under-hood fuse box.

1. Disconnect the 14P connector from the second row seat heater control unit .

GHH326020Courtesy of HONDA, U.S.A., INC.

2. 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 3.

3. Reconnect the 14P connector to the control unit, 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, go to step 4.
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
2 PNK Vehicle ON mode Measure the voltage to ground:
There should be battery voltage.
  • Blown No. F7 (20 A) fuse in the rear fuse/relay box
  • Faulty second row seat heater relay
  • An open or high resistance in the wire
9 LT GRN Vehicle ON mode Measure the voltage to ground:
There should be battery voltage.
  • Blown No. D22 (15 A) fuse in the driver's under-dash fuse/relay box
  • Blown No. E20 (7.5 A) fuse in the passenger's under-dash fuse/relay box
  • An open or high resistance in the wire
14 BRN In all power modes Measure the voltage to ground:
There should be less than 0.2 V.
  • Poor ground (G604)
  • An open or high resistance in the ground wire
4 BRN In all power modes Measure the voltage to ground:
There should be less than 0.2 V.
  • Poor ground (G604)
  • An open or high resistance in the ground wire
1 RED Vehicle ON mode, left second row seat heater switch pressed Measure the voltage to ground:
There should be battery voltage.
  • Faulty left second row seat heater
  • Poor ground (G601) or an open in the ground wire
  • An open or high resistance in the wire
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
3 LT BLU Vehicle ON mode, right second row seat heater switch pressed Measure the voltage to ground:
There should be battery voltage.
  • Faulty right second row seat heater
  • Poor ground (G604) or an open in the ground wire
  • An open or high resistance in the wire

4. Turn the vehicle to the OFF (LOCK) mode.

5. Disconnect the 14P connector from the control unit, 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, the control unit must be faulty; replace it .
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
10 BLU Under all conditions Check for continuity between terminal 10 and climate control unit connector B (28P) terminal No. 10:
There should be continuity.
  • An open in the B-CAN wire
  • Faulty climate control unit
11 PNK Check for continuity between terminal 11 and climate control unit connector B (28P) terminal No. 9:
There should be continuity.
7 PUR Under all conditions Check for continuity between terminals No. 7 and No. 13:
There should be continuity.
  • Faulty left second row seat cushion heater
  • An open or high resistance in the wire
13 WHT
6 GRN Under all conditions Check for continuity between terminals No. 6 and No. 12:
There should be continuity.
  • Faulty right second row seat cushion heater
  • An open or high resistance in the wire
12 BRN
Factory Service Tools

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When to See a Mechanic

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

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

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