MICU Input Test

WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.

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

Driver's MICU

Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
Remove the driver's dashboard undercover (see DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION )
Disconnect driver's under-dash fuse/relay box connectors F, Q, and R
NOTE: All connector views are wire side of female terminals

Fig 1: Driver's Under-Dash Fuse/Relay Box Connectors Terminals Chart
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 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, go to step 6

TEST CONDITION CAVITY CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
F7 F30	ORN GRN	Under all conditions	Connect terminals F16 and F30 and terminal F7 to body ground The windshield wiper motor should run at high speed	Blown No 3-7 (WIP MTR) (30 A) fuse in the under-hood fuse/relay box Faulty relay circuit board Faulty windshield wiper motor Poor ground (G301) or open in ground wire An open or high resistance in the wire
F8	YEL	Run the windshield wiper motor by connecting terminals F16 and F30 to terminal F7 and body ground	Connect terminal F8 to body ground The windshield wiper motor speed should change from high speed to low speed	Faulty under-hood fuse/relay box Faulty relay circuit board Faulty windshield wiper motor An open or high resistance in the wire
F9	PNK	Run the windshield wiper motor by connecting terminals F16 and F30 to terminal F7 and body ground	Check for continuity to ground The needle of the ohmmeter should pulse 1 time per wiper motor cycle NOTE: Use a DVOM	Faulty windshield wiper motor An open or high resistance in the wire Poor ground (G301) or open in ground wire

Reconnect the connectors to the driver's under-dash fuse/relay box, turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, 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, go to step 7

TEST CONDITION CAVITY CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
Q1	BLK	In all ignition switch positions or all pwer modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G402) or an open in ground wire An open or high resistance in the wire
Q2	BRN	In all ignition switch positions or all pwer modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G401) or open in ground wire An open or high resistance in the wire
R2	BRN	In all ignition switch positions or all pwer modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G401) or open in ground wire An open or high resistance in the wire
R5	BLK	In all ignition switch positions or all pwer modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G402) or open in ground wire An open or high resistance in the wire
F4 A/T	RED	Transmission range switch in P	Measure the voltage to ground There should be less than 0 2V	Poor ground (G101) or open in ground wire Faulty transmission range switch An open or high resistance in the wire
F4 A/T	RED	Transmission range switch in any other position than P	Measure the voltage to ground There should be about 5 V	A short to ground in the wire
F20	LT GRN	Brake pedal pressed	Measure the voltage to ground There should be battery voltage	Blown No 10 (20 A) fuse in the under-hood fuse/relay box Faulty brake pedal position switch An open or high resistance in the wire
F20	LT GRN	Brake pedal released	Measure the voltage to ground There should be no voltage	Faulty brake pedal position switch A short to power in the wire
R15 R4	ORN GRY	Wiper switch (INT or LO) ON	Measure the voltage between terminals R15 and R4 There should be less than 0 2V	Faulty wiper/washer switch An open or high resistance in the wire
R15 R4	ORN GRY	Wiper switch OFF	Measure the voltage between terminals R15 and R4 There should be about 5 V	Faulty wiper/washer switch A short to ground in the wire
R16 R4	WHT GRY	Wiper switch (LO or HI) ON	Measure the voltage between terminals R16 and R4 There should be less than 0 2V	Faulty wiper/washer switch An open or high resistance in the wire
R16 R4	WHT GRY	Wiper switch OFF	Measure the voltage between terminals R16 and R4 There should be about 5 V	Faulty wiper/washer switch A short to ground in the wire
R17 R4	GRN GRY	Wiper switch (MIST) ON	Measure the voltage between terminals R17 and R4 There should be less than 0 2V	Faulty wiper/washer switch An open or high resistance in the wire
R17 R4	GRN GRY	Wiper switch OFF	Measure the voltage between terminals R17 and R4 There should be about 5 V	Faulty wiper/washer switch A short to ground in the wire
R18 R4	YEL GRY	Washer switch ON	Measure the voltage between terminals R18 and R4 There should be less than 0 2V	Faulty wiper/washer switch An open or high resistance in the wire
R18 R4	YEL GRY	Washer switch OFF	Measure the voltage between terminals R18 and R4 There should be about 5 V	Faulty wiper/washer switch A short to ground in the wire

Passenger's MICU

Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and remove the front passenger's kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS )
Disconnect passenger's under-dash fuse/relay box connectors A and E
NOTE: All connector views are wire side of female terminals

Fig 2: Passenger's Under-Dash Fuse/Relay Box Connectors Terminals Chart
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 10

TEST CONDITION CAVITY CHART

Cavity

Wire

Test condition

Test Desired result

Possible cause if desired result is not obtained

GRN

Ignition switch ON (II), or power mode ON

Connect terminals A1 and E9
The windshield washer motor should run

Faulty windshield washer motor
An open or high resistance in the wire

A25⁽¹⁾

WHT

Under all conditions

Connect to ground
The headlight washer motor should run

Blown No 2 (H/L WASHER) (30 A) fuse in the under-hood fuse/relay box
Poor ground (G203) or open in ground wire
Faulty headlight washer motor
Faulty headlight washer motor relay
An open or high resistance in the wire

A4⁽¹⁾

YEL

Headlight washer switch pushed

Check for continuity to ground
There should be continuity

Faulty headlight washer switch
Poor ground (G401) or open in ground wire
An open or high resistance in the wire

Headlight washer switch released

Check for continuity to ground
There should be continuity

Faulty headlight washer switch
A short to around in the wire

⁽¹⁾	With headlight washer

Reconnect the connectors to the passenger's under-dash fuse/relay box, 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, go to step 11

TEST CONDITION CAVITY CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
A1	PNK	Ignition switch ON (II), or power mode ON	Measure the voltage to ground There should be battery voltage	Blown No 3 (20 A) fuse in the driver's under-dash fuse/relay box Faulty driver's under-dash fuse/relay box An open in or high resistance in the wire
A35	BRN	Ignition switch ON (II), or power mode ON	Measure the voltage to ground There should be battery voltage	Blown No 12 (7 5 A) fuse in the driver's under-dash fuse/relay box Faulty driver's under-dash fuse/relay box An open or high resistance in the wire
E16	BLK	In all ignition switch positions or all power modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G203) or open in ground wire An open or high resistance in the wire
E15	BLK	In all ignition switch positions or all power modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G201) or open in ground wire An open or high resistance in the wire
A36	BLK	In all ignition switch positions or all power modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G405) or open in ground wire An open or high resistance in the wire
A37	GRY	In all ignition switch positions or all power modes	Measure the voltage to ground There should be less than 0 2V	Poor ground (G401) or open in ground wire An open or high resistance in the wire

If multiple failures are found on more than one control unit, replace the driver's under-dash fuse/relay box (includes the driver's MICU) (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION ) If input failures are related to a particular control unit, replace the control unit