Driver's MPCS Unit Input Test

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before testing the driver's MPCS unit, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A

Turn the ignition switch to LOCK (0).
Remove the driver's door panel FRONT DOOR PANEL REMOVAL/INSTALLATION ).
Disconnect driver's MPCS unit connectors A (40P) and B (14P).

Fig 1: Identifying Driver's MPCS Unit Connectors A (40P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Driver's MPCS Unit Connectors B (14P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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.

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
A28	LT GRN	Under all conditions (Under-dash fuse/relay box connector J (21P) disconnected	Check for continuity between terminal A28 and under-dash fuse/relay box connector J (21P) terminal No. 4: There should be continuity.	An open or high resistance in the wire.
A28	LT GRN		Check for continuity to ground: There should be no continuity.	A short to ground in the wire

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 driver's MPCS unit.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
A5 B14	BLK	In all ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G601) or an open in the ground wire Faulty under-dash fuse/relay box An open or high resistance in the wire
A7	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
A25	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