MICU Input Test

WARNING: This page is about a different car, the 2011 Honda CR-V, 2010 Honda CR-V, 2009 Honda CR-V, 2008 Honda CR-V, and 2007 Honda CR-V. However, it is still accessible from the selected car via links, so may be relevant.

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

Check the No. 10 (7.5 A) fuse in the under-dash fuse/relay box. If the fuse is blown, replace it and go to step 2.
Disconnect under-dash fuse/relay box connectors E, F, K, R, and T.
NOTE: All connector views are wire side of female terminals.

Fig 1: Identifying Multiplex Integrated Control Unit 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 4.

With the connectors still disconnected, do these input tests at the following connector.

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 5.

TEST CONDITION REFERENCE CHART

Cavity

Wire

Test condition

Test: Desired result

Possible cause if desired result is not obtained

PUR

Under all conditions (With moonroof: select the interior light switch in DOOR position)

Attach to ground: The ceiling light and map lights⁽¹⁾ should come on.

Blown No. 22 (7.5 A) fuse in the under-hood fuse/relay box
Blown bulb(s)
Faulty ceiling light
Faulty map light⁽¹⁾
Faulty interior light switch⁽¹⁾
An open or high resistance in the wire

R13

RED

Under all conditions

Attach to ground: The ignition key light should come on.

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

⁽¹⁾	With moonroof

Reconnect the connectors to the under-dash fuse/relay box, turn the ignition switch to ON (II), and do these input tests at the following connectors.

If any test indicates a problem, find and correct the cause, then recheck the system.
If all the input tests prove OK, the MICU must be faulty; replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).

TEST CONDITION REFERENCE CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
E6	BLK	In all ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G602) or an open in the ground wire An open or high resistance in the wire
E33	BLK	In all ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G602) or an open in the ground wire An open or high resistance in the wire
F20	BLK	In all ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G401) or an open in the ground wire An open or high resistance in the wire
T34	BLK	In ail ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G502) or an open in the ground wire An open or high resistance in the wire
E37	GRN	Driver's door open	Measure the voltage to ground: There should be less than 0.2 V.	Faulty driver's door switch 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 A short to ground in the wire
E3	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 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 A short to ground in the wire
E2	GRY	Right rear door open	Measure the voltage to ground: There should be less than 0.2 V.	Faulty right rear door switch 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 A short to ground in the wire
E17	WHT	Left rear door open	Measure the voltage to ground: There should be less than 0.2 V.	Faulty left rear door switch 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 A short to ground in the wire
R16	GRY	Ignition key inserted into the ignition switch	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G501) or an open in the ground wire Faulty ignition key switch An open or high resistance in the wire
R16	GRY	Ignition switch OFF and 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
T23	WHT	Driver's door lock knob switch unlocked	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G501) or an open in the ground wire Faulty driver's door lock knob switch An open or high resistance in the wire
T23	WHT	Driver's door lock knob switch locked	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
T24	LT GRN	Driver's door lock knob switch unlocked	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
T24	LT GRN	Driver's door lock knob switch locked	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G501) or an open in the ground wire Faulty driver's door lock knob switch An open or high resistance in the wire