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 )
Before testing, make sure the No 12 (7 5 A), No 15 (10 A), No 26 (10 A), No 27 (10 A), No 28(10 A), and No 30 (10 A) fuse in the driver's under-dash fuse/relay box, and No 1 (10 A), No 2 (10 A), No 3 (10 A), and No 4 (10 A) fuse in the passenger's under-dash fuse/relay box are OK

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 B, D, E, F, G, 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 INPUT CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
D6	BRN	Under all conditions	Connect terminals C5 and D6 with a jumper wire The back-up lights should come on	Blown bulb Poor ground(G603) or open in ground wire An open or high resistance in the wire
D11	RED	Under all conditions	Connect terminals F19 and D11 with a jumper wire The taillights, license plate lights and the rear side marker lights should come on	Blown bulb Poor ground(G603) or open in ground wire An open or high resistance in the wire
E12	LT GRN	Brake pedal pressed	Connect terminals F20 and E12 with a jumper wire The brake lights should come on	Faulty LED Poor ground (G402, G603) or open in ground wire 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 ground in the wire
F10	RED	Under all conditions	Connect terminals F19 and F10 with a jumper wire The left front parking light and the left front side marker light should come on	Blown left front parking and side marker bulb Poor ground(G302) or open in ground wire An open or high resistance in the wire
F13	PNK	Under all conditions	Connect terminals F19 and F13 with a jumper wire The left headlight (high beam) should come on	Blown left high beam bulb Poor ground (G302) or open in ground wire An open or high resistance in the wire
F21	RED	Under all conditions	Connect terminals F19 and F21 with a jumper wire The left headlight (low beam) should come on	Blown left low beam (HID) bulb Faulty HID unit Poor ground(G302) or open in ground wire An open or high resistance in the wire
G12	YEL	Under all conditions	Connect terminals F19 and G12 with a jumper wire The left fog light should come on	Blown left fog bulb Poor ground(G302) or open in ground wire An open or high resistance in the wire

Reconnect the connectors to the driver'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 7

TEST CONDITION INPUT CHART

Cavity

Wire

Test condition

Test Desired result

Possible cause if desired result is not obtained

WHT

Under all conditions

Measure the voltage to ground
There should be battery voltage

Blown No 3-8 (AS LT MAIN) (30 A) fuse in the under-hood fuse/relay box
Faulty driver's under-dash fuse/relay box
An open or high resistance in the wire

BLK

In all ignition switch positions or all power modes

Measure the voltage to ground
There should be less than 0 2V

Poor ground(G402)
An open or high resistance in the wire

BRN

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

BRN

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

BLK

In all ignition switch positions or all power 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

D12

GRN

Driver's door open

Measure the voltage to ground
There should be less than 0 2V

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 aboutt 5 V

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

F11

WHT

Under all conditions

Measure the voltage to ground
There should be battery voltage

Blown No 15(10 A) fuse in the under-hood fuse/relay box
An open or high resistance in the wire

F17

GRN

Under all conditions

Measure the voltage to ground
There should be battery voltage

Blown No 3-8 (AS LT MAIN) (30 A) fuse in the under-hood fuse/relay box
An open or high resistance in the wire

F19

BLK/RED

Under all conditions

Measure the voltage to ground
There should be battery voltage

Blown No 3-6 (DR LT MAIN) (30 A) fuse in the under-hood fuse/relay box
An open or high resistance in the wire

F27
(A/T)

WHT

Ignition switch ON (II), or power mode ON Transmission range switch in any other position than R

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

Ignition switch ON (II), or power mode ON Lever in R position

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

F27
(M/T)

BRN

Power mode ON

Connect terminals F28 and F27 with a jumper wire: The back-up lights should come on

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 wire
Blown bulb(s)
A short to ground in the wire
Poor ground (G603) or open in ground wire

Q18⁽¹⁾

RED

Ignition key inserted into the ignition switch

Measure the voltage to ground
There should be less than 0 2V

Faulty ignition key switch
An open or high resistance in the wire
Poor ground(G403) or open in ground wire

Ignition key removed from the ignition switch

Measure the voltage to ground
There should be about 5 V

Faulty ignition key switch
A short to ground in the wire

Q18⁽²⁾

RED

Keyless access remote inserted into the remote slot

Measure the voltage to ground
There should be less than 0 2V

Faulty power control unit
An open or high resistance in the wire

Keyless access remote removed frome the remote slot

Measure the voltage to ground
There should be about 5 V

Faulty power control unit
An open or high resistance in the wire

R6
R3

PNK
BLK

Combination light switch OFF

Measure the voltage between terminals R6 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Combination light switch in any other position than OFF

Measure the voltage between terminals R6 and R3
There should be atbout 5 V

Faulty combination light switch
A short to ground in the wire

R7
R3

GRY
BLK

Combination light switch (PARKING LIGHT position) ON

Measure the voltage between terminals R7 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Combination light switch OFF

Measure the voltage between terminals R7 and R3
There should be about 5 V

Faulty combination light switch
A short to ground in the wire

R8
R3

BRN
BLK

Combination light switch (headlight) ON

Measure the voltage between terminals R8 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Combination light switch OFF

Measure the voltage between terminals R8 and R3
There should be about 5 V

Faulty combination light switch
A short to ground in the wire

R21
R3

RED
BLK

Combination light switch lever pulled (Passing)

Measure the voltage between terminals R21 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Combination light switch lever released (OFF)

Measure the voltage between terminals R21 and R3
There should be about 5 V

Faulty combination light switch
A short to ground in the wire

R22
R3

LT BLU
BLK

Combination light switch (Dimmer) in high beam position

Measure the voltage between terminals R22 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Combination light switch (Dimmer) in low beam position

Measure the voltage between terminals R22 and R3
There should be about 5 V

Faulty combination light switch
A short to ground in the wire

R10
R3

PUR
BLK

Fog light switch ON

Measure the voltage between terminals R10 and R3
There should be less than 0 2V

Faulty combination light switch
An open or high resistance in the wire

Fog light switch OFF

Measure the voltage between terminals R10 and R3
There should be about 5 V

Faulty combination light switch
A short to ground in the wire

⁽¹⁾	Without keyless access system

⁽²⁾	With keyless access system

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 passenger's side 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.
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

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 11

TEST CONDITION INPUT CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
A8	BLU	Under all conditions	Measure the voltage to ground There should be battery voltage	Blown No 3-8 (AS LT MAIN) (30 A) fuse in the under-hood fuse/relay box Faulty driver's under-dash fuse/relay box An open or high resistance in the wire
A17	RED	Under all conditions	Check for continuity between passenger's under-dash fuse/relay box connector A (38P) terminal No 17 and driver's under-dash fuse/relay box connector Q (20P) terminal No 8 There should be continuity	An open or high resistance in the wire
E2	ORN	Under all conditions	Connect terminals A8 and E2 with a jumper wire The right headlight (high beam) should come on	Blown right high beam bulb Poor ground(G203) or open in ground wire An open or high resistance in the wire
E10	BRN	Under all conditions	Connect terminals A8 and E10 with a jumper wire The right headlight (low beam) should come on	Blown right low beam (HID) bulb Faulty HID unit Poor ground(G203) or open in ground wire An open or high resistance in the wire
E12	GRY	Under all conditions	Connect terminals A8 and E12 with a jumper wire The right front parking light and the right front side marker light should come on	Blown right front parking or side marker bulb Poor ground(G203) or open in ground wire An open or high resistance in the wire
E13	LT BLU	Under all conditions	Connect terminals A8 and E13 with a jumper wire The right fog light should come on	Blown right fog bulb Poor ground(G201) or open in ground wire An open or high resistance in the wire

Reconnect the connectors to the passenger'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 12

TEST CONDITION INPUT CHART

Cavity	Wire	Test condition	Test Desired result	Possible cause if desired result is not obtained
A14	WHT	Under all conditions	Measure the voltage to ground There should be battery voltage	Blown No 15(10 A) fuse in the under-hood fuse/relay box Faulty driver's under-dash fuse/relay box An open 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
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
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
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

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