Multiplex Integrated Control Unit

Turn the ignition switch OFF.
Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
Disconnect under-dash fuse/relay box connectors E, F, H, K, N, P, and Q.
NOTE: All connectors are shown from wire side of female terminals.

Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors 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.

With the connectors still disconnected, make these input tests at the connectors.

If any test indicates a problem, find and correct the cause, then recheck the system.
If the input tests prove OK, go to step 6.

WIRE TEST CONDITION CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
H9	BLK	Under all conditions	Check for continuity to ground: There should be continuity.	Poor ground (G503, G601) An open in the wire
F5	BLU/BLK	Connect the F5 terminal to the battery positive terminal. Trunk lid opener main switch ON.	Check trunk lid opener solenoid operation: Trunk lid should open.	Poor ground(G701) Faulty trunk lid opener solenoid An open in the wire
K2	YEL/GRN	Connect the battery positive terminal to K12 (K2) terminal, and K2 (K12) terminal to H9 terminal with a jumper wire.	Check actuator operation: The driver's door lock actuator should lock (unlock).	Faulty driver's door lock actuator An open in the wire
K12	YEL/BLK			Faulty driver's door lock actuator An open in the wire
N7	YEL/BLK	Connect the battery positive terminal to N7 (N9) terminal, and N9 (N7) terminal to H9 terminal with a jumper wire.	Check actuator operation: The front passenger's door lock actuator should lock (unlock).	Faulty front passenger's door lock actuator An open in the wire
N9	YEL
E2	YEL/BLK	Connect the battery positive terminal to E2 (E8) terminal, and E8 (E2) terminal to H9 terminal with a jumper wire.	Check actuator operation: The left rear door lock actuator should lock (unlock).	Faulty left rear door lock actuator An open in the wire
E8	YEL			Faulty left rear door lock actuator An open in the wire
H3	YEL/BLK	Connect the battery positive terminal to H3 (H10) terminal, and H10 (H3) terminal to H9 terminal with a jumper wire.	Check actuator operation: The right rear door lock actuator should lock (unlock).	Faulty right rear door lock actuator An open in the wire
H10	YEL			Faulty right rear door lock actuator An open in the wire
Q14	WHT	Under all conditions	Apply battery power to Q14 terminal momentarily: The buzzer should chirp.	Poor ground (G302) Faulty keyless buzzer An open in the wire

Reconnect all connectors to the under-dash fuse/relay box. Turn the ignition switch ON (II), and make these input tests at the appropriate connectors on the under-dash fuse/relay box.

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 7.

WIRE TEST CONDITION CHART

Cavity

Wire

Test condition

Test: Desired result

Possible cause if desired result is not obtained

BRN/WHT

Front passenger's door lock knob switch unlocked

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G506)
Faulty front passenger's door lock knob switch
An open in the wire

Front passenger's door lock knob switch locked

Measure the voltage to ground:
There should be 5 V or more.

Faulty front passenger's door lock knob switch
A short to ground in the wire

PNK/BLU

Front passenger's door lock switch unlocked

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G506)
Faulty front passenger's door lock switch
An open in the wire

Front passenger's door lock switch in neutral

Measure the voltage to ground:
There should be 5 V or more.

Faulty front passenger's door lock switch
A short to ground in the wire

P25

PNK/BLK

Front passenger's door lock switch locked

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G506)
Faulty front passenger's door lock switch
An open in the wire

Front passenger's door lock switch in neutral

Measure the voltage to ground:
There should be 5 V or more.

Faulty front passenger's door lock switch
A short to ground in the wire

BRN

Left rear door lock knob switch unlocked

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G503, G601)
Faulty left rear door lock knob switch
An open in the wire

Left rear door lock knob switch locked

Measure the voltage to ground:
There should be 5 V or more.

Faulty left rear door lock knob switch
A short to ground in the wire

LT BLU

Right rear door lock knob switch unlocked

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G602)
Faulty right rear door lock knob switch
An open in the wire

Right rear door lock knob switch locked

Measure the voltage to ground:
There should be 5 V or more.

Faulty right rear door lock knob switch
A short to ground in the wire

PUR

Under all conditions

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G504)
Faulty connections at the audio unit
Faulty audio unit
An open in the wire

P13

BLU

Ignition key inserted into the ignition switch.

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G501)
Faulty ignition key switch
An open in the wire

Ignition switch OFF and ignition key removed from the ignition switch.⁽¹⁾

Measure the voltage to ground:
There should be 5 V or more.

Faulty ignition key switch
A short to ground in the wire

E15

GRN

Driver's door open

Measure the voltage to ground:
There should be less than 1 V.

Faulty driver's door switch
An open in the wire

Driver's door closed

Measure the voltage to ground:
There should be 5 V or more.

Faulty driver's door switch
A short to ground in the wire

H12

LT GRN/ RED

Front passenger's door open

Measure the voltage to ground:
There should be less than 1 V.

Faulty front passenger's door switch
An open in the wire

Front passenger's door closed

Measure the voltage to ground:
There should be 5 V or more.

Faulty front passenger's door switch
A short to ground in the wire

E14

GRN/YEL

Left rear door open

Measure the voltage to ground:
There should be less than 1 V.

Faulty left rear door switch
An open in the wire

Left rear door closed

Measure the voltage to ground:
There should be 5 V or more.

Faulty left rear door switch
A short to ground in the wire

H13

GRN/WHT

Right rear door open

Measure the voltage to ground:
There should be less than 1 V.

Faulty right rear door switch
An open in the wire

Right rear door closed

Measure the voltage to ground:
There should be 5 V or more.

Faulty right rear door switch
A short to ground in the wire

P24

ORN

Trunk lid open

Measure the voltage to ground:
There should be less than 1 V.

Poor ground (G701)
Faulty trunk lid latch switch
An open in the wire

Trunk lid closed

Measure the voltage to ground:
There should be 5 V or more.

Faulty trunk lid latch switch
A short to ground in the wire

⁽¹⁾	Insert the key into the ignition switch and turn the ignition switch ON (II) before continuing to the next step.

Door Multiplex Control Unit

Turn the ignition switch OFF.
Remove the power window master switch (see REAR POWER WINDOW MOTOR TEST ).
Disconnect the 22P connector from the power window master switch.

Fig 2: Identifying Door Multiplex Control Unit 22P Connector
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 11.

With the connector still disconnected, make these input tests at the connector.

If the test indicates a problem, find and correct the cause, then recheck the system.
If the input tests prove OK, go to step 12.

WIRE TEST CONDITION CHART

Cavity	Wire	Test conditions	Test: Desired result	Possible cause if desired result is not obtained
A10	BLK/YEL	Under all conditions	Attach to ground: The security indicator should come on.	Faulty security indicator An open in the wire
A16	PNK/BLK	Under all conditions	Check for continuity between the A16 terminal and under-dash fuse/relay box connector J terminal No. 10: There should be continuity.	An open in the wire

Reconnect the connector to the door multiplex control unit. Turn the ignition switch ON (II) and make these input tests at the connectors.

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 13.

WIRE TEST CONDITION CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
A7	WHT/BLK	Driver's door lock knob switch unlocked	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door lock knob switch An open in the wire
A7	WHT/BLK	Driver's door lock knob switch locked	Measure the voltage to ground: There should be 5 V or more.	Faulty driver's door lock knob switch A short to ground in the wire
A6	YEL/RED	Driver's door lock knob switch locked	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door lock knob switch An open in the wire
A6	YEL/RED	Driver's door lock knob switch unlocked	Measure the voltage to ground: There should be 5 V or more.	Faulty driver's door lock knob switch A short to ground in the wire
A14	WHT/BLU	Driver's door lock switch pressed (LOCK)	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door lock switch An open in the wire
A14	WHT/BLU	Driver's door lock switch in neutral or pressed (UNLOCK)	Measure the voltage to ground: There should be 5 V or more.	Faulty driver's door lock switch A short to ground in the wire
A15	WHT/GRN	Driver's door lock switch pressed (UNLOCK)	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door lock switch An open in the wire
A15	WHT/GRN	Driver's door lock switch in neutral or pressed (LOCK)	Measure the voltage to ground: There should be 5 V or more.	Faulty driver's door lock switch A short to ground in the wire
A18	WHT	Driver's door key cylinder switch in UNLOCK	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door key cylinder switch An open in the wire A short to ground in the wire
		Driver's door key cylinder switch in neutral	Measure the voltage to ground: There should be 5 V or more.
		Driver's door key cylinder switch in LOCK	Measure the voltage to ground: There should be 5 V or more.
A19	WHT/RED	Driver's door key cylinder switch in LOCK	Measure the voltage to ground: There should be less than 1 V.	Poor ground (G503, G601) Faulty driver's door key cylinder switch An open in the wire A short to ground in the wire
		Driver's door key cylinder switch in neutral	Measure the voltage to ground: There should be 5 V or more.
		Driver's door key cylinder switch in UNLOCK	Measure the voltage to ground: There should be 5 V or more.

If all the input tests prove OK, and no DTCs were found during MICS troubleshooting (B-CAN System Diagnosis Test Mode A) (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ), go to the B-CAN system input and output index (see B-CAN SYSTEM SWITCH DEVICE INDEX ). If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU). If input failures are related to a particular control unit, replace that control unit.