Control Unit Input Test

NOTE: Before testing, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

MICU

Turn the ignition switch to LOCK (0).
Remove the driver's dashboard lower cover (see INSTRUMENT PANEL REMOVAL/INSTALLATION ).
Disconnect under-dash fuse/relay box connectors E, F, G, K, R, and T.
NOTE: All connector views are shown from the wire side of female terminals.

Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors E (42P), F (34P), G (21P), K (8P), R (20P), And T (34P) Terminals
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.

Reconnect the connectors to the under-dash fuse/relay box, 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 6.

Cavity

Wire

Test condition

Test: Desired result

Possible cause if desired result is not obtained

BLK

In all ignition switch positions

Measure the voltage to ground: There should be less than 0.2 V.

Poor ground (G401)
An open or high resistance in the ground wire

T34

F20

Poor ground (G501)
An open or high resistance in the ground wire

PNK

Under all conditions

Measure the voltage to ground: There should be battery voltage.

Blown No. 23 (10 A) fuse in the under-hood fuse/relay box
Faulty under-hood fuse/relay box
An open or high resistance in the wire

WHT

Under all conditions

Measure the voltage to ground: There should be battery voltage.

Blown No. 22 (7.5 A) fuse in the under-hood fuse/relay box
Faulty under-hood fuse/relay box
An open or high resistance in the wire

RED

Ignition key inserted into the ignition switch

Measure the voltage to ground: There should be less than 0.2 V.

Faulty ignition key switch
Poor ground (G401) or an open in the ground wire
An open or high resistance in the wire

Ignition switch in LOCK (0) position and the ignition key removed from the ignition switch

Measure the voltage to ground: There should be at least 5 V.

Faulty ignition key switch
A short to ground in the wire
Faulty MICU

E37

YEL

Driver's door open

Measure the voltage to ground: There should be less than 0.2 V.

Faulty driver's door switch
Faulty driver's door switch ground
An open or high resistance in the wire

Driver's door closed

Measure the voltage to ground: There should be at least 5 V.

Faulty driver's door switch
Faulty under-dash fuse/relay box
A short to ground in the wire

LT GRN

Front passenger's door open

Measure the voltage to ground: There should be less than 0.2 V.

Faulty front passenger's door switch
Faulty front passenger's door switch ground
An open or high resistance in the wire

Front passenger's door closed

Measure the voltage to ground: There should be at least 5 V.

Faulty front passenger's door switch
Faulty under-dash fuse/relay box
A short to ground in the wire

E17

LT BLU

Left rear door open

Measure the voltage to ground: There should be less than 0.2 V.

Faulty left rear door switch
Faulty left rear door switch ground
An open or high resistance in the wire

Left rear door closed

Measure the voltage to ground: There should be at least 5 V.

Faulty left rear door switch
Faulty under-dash fuse/relay box
A short to ground in the wire

GRY

Right rear door open

Measure the voltage to ground: There should be less than 0.2 V.

Faulty right rear door switch
Faulty right rear door switch ground
An open or high resistance in the wire

Right rear door closed

Measure the voltage to ground: There should be at least 5 V.

Faulty right rear door switch
Faulty under-dash fuse/relay box
A short to ground in the wire

E36⁽¹⁾

LT GRN

Tailgate open

Measure the voltage to ground: There should be less than 0.2 V.

Faulty tailgate latch switch
Poor ground (G601) or an open in the ground wire
An open or high resistance in the wire

Tailgate closed

Measure the voltage to ground: There should be at least 5 V.

Faulty tailgate latch switch
A short to ground in the wire

R10

WHT

Under all conditions

Measure the voltage to ground: There should be battery voltage.

Faulty under-dash fuse/relay box
An open or high resistance in the wire

PNK

Interior light switch in the middle (DOOR) position

Connect a jumper wire to ground: The individual map lights and ignition key light should come on.

Faulty under-dash fuse/relay box
Faulty interior light switch
Faulty individual map lights
Faulty ignition key switch
Blown bulb (s)
An open or high resistance in the wire

⁽¹⁾	Without power tailgate

Door Multiplex Control Unit

Turn the ignition switch to LOCK (0).
Remove the power window master switch (see REAR POWER WINDOW SWITCH TEST/REPLACEMENT ).
Disconnect the 37P connector from the power window master switch.

Fig 2: Identifying Power Window Master Switch 37P Connector Terminals
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 10.

Reconnect the 37P connector to the power window master switch, 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 11.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
32	BLK	Under all conditions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G401) An open or high resistance in the ground wire
37	BLK	Under all conditions
13	WHT	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Blown No. 23 (10 A) fuse in the under-hood fuse/relay box Faulty under-dash fuse/relay box An open or high resistance in the wire
30	BRN	Driver's door lock knob switch in LOCK	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G401) or an open in the ground wire Faulty driver's door lock knob switch An open or high resistance in the wire
30	BRN	Driver's door lock knob switch in UNLOCK	Measure the voltage to ground: There should be at least 5 V.	Faulty driver's door lock knob switch A short to ground in the wire Faulty power window master switch
31	RED	Driver's door lock knob switch in UNLOCK	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G401) or an open in the ground wire Faulty driver's door lock knob switch An open or high resistance in the wire
31	RED	Driver's door lock knob switch in LOCK	Measure the voltage to ground: There should be at least 5 V.	Faulty driver's door lock knob switch Faulty power window master switch A short to ground in the wire

If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU) (see REMOVAL AND INSTALLATION ). If input failures are related to a particular control unit, replace the control unit.