Driver's MPCS Unit Input Test

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