Control Unit Input Test

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

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 ).
Before testing, make sure the No. 7 (10 A), No. 21 (7.5 A) and No. 30 (10 A) fuses in the under-dash fuse/relay box, and the No. 1 (10 A), No. 2 (10 A), No. 3 (10 A), No. 4 (10 A), No. 5 (7.5 A), No. 6 (30 A), No. 13 (20 A), No. 18(15 A) and No. 19 (15 A) fuses in the under-hood fuse/relay box are OK.

MICU

Turn the ignition switch to LOCK (0).
Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
Disconnect under-dash fuse/relay box connectors A, B, D, E, F, H, N, P, Q and X.
NOTE: All connector views are wire side of female terminals.

Fig 1: Under-Dash Fuse/Relay Box Connectors Views
Courtesy of AMERICAN HONDA MOTOR CO., INC.

*: Connector view shown rotated 180" from actual position in the under-dash fuse/relay box.

With the connectors still disconnected, 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 5.

Cavity	Wire	Test Condition	Test: Desired result	Possible cause if desired result is not obtained
D11	LT GRN	Disconnect relay control module connector E (14P)	Check for continuity between terminal D11 and relay control module connector E (14P) terminal No. 1: There should be continuity.	An open in the B-CAN wire
N22	LT GRN	Disconnect gauge control module connector A (12P)	Check for continuity between terminal N22 and gauge control module connector A (12P) terminal No. 5: There should be continuity.	An open in the B-CAN wire
X27	LT GRN	Disconnect wiper/washer switch (combination switch control unit) 8P connector	Check for continuity between terminal X27 and wiper/washer switch 8P connector terminal No. 4: There should be continuity.	An open in the B-CAN wire
P3	WHT	Disconnect wiper/washer switch (combination switch control unit) 8P connector and relay control module connector E (14P)	Check for continuity between terminal P3, wiper/washer switch 8P connector terminal No. 1 and relay control module connector E (14P) terminal No. 11: There should be continuity.	An open or high resistance in the wire
P14	BRN	Disconnect the automatic lighting sensor 5P connector and gauge control module connector A (12P)	Check for continuity between terminal P14, gauge control module connector A (12P) terminal No. 10 and automatic lighting sensor 5P connector terminal No. 1: There should be continuity.	An open or high resistance in the wire
P27	ORN		Check for continuity between terminal P27, gauge control module connector A (12P) terminal No. 9, and automatic lighting sensor 5P connector terminal No. 3: There should be continuity.	An open or high resistance in the wire
P30	PUR	Disconnect the automatic lighting sensor 5P connector	Check for continuity between terminal P30 and automatic lighting sensor 5P connector terminal No. 5: There should be continuity.	An open or high resistance in the wire
P5	BRN	Under all conditions	Connect battery power to the terminal P5: The back-up lights should come on.	Poor ground (G701) or an open in the ground wire An open or high resistance in the wire Blown bulb
F9	GRY	Under all conditions	Connect battery power to the terminal F9: The taillights, license plate lights and rear side marker lights should come on.	Poor ground (G701, G702) or an open in the ground wire Faulty rear fuse/relay box Faulty LED Blown bulb An open or high resistance in the wire

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
P1	BRN	In all ignition switch positions	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G502) An open or high resistance in the ground wire
E9	BLK			Poor ground (G601) An open or high resistance in the ground wire
H9
Q4
A4	GRN	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire Faulty under-dash fuse/relay box Faulty IG2 cut relay Faulty ignition switch
A6	PNK	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire Faulty under-dash fuse/relay box Faulty ignition switch
B4	WHT	Under all conditions	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire
D12	WHT	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Faulty under-dash fuse/relay box
D6	YEL	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	Faulty under-dash fuse/relay box
X34	YEL	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	Faulty under-dash fuse/relay box
X35	WHT	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Faulty under-dash fuse/relay box
N20	PNK	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	Faulty under-dash fuse/relay box
P7	PNK	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire
D3	GRY	Combination light switch (PARKING LIGHT position) ON	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire Faulty under-hood fuse/relay box Faulty relay control module in the under-hood fuse/relay box
P20	PUR	Ignition switch ON (II) Transmission range switch in any position other than R	Measure the voltage to ground: There should be battery voltage.	Faulty transmission range switch Faulty under-dash fuse/relay box An open or high resistance in the wire A short to ground in the wire
P20	PUR	Ignition switch ON (II) Transmission range switch in R position	Measure the voltage to ground: There should be less than 0.2 V.	Faulty transmission range switch An open or high resistance in the wire Poor ground (G101) or an open in the ground wire

Relay Control Module

Turn the ignition switch to LOCK (0).
Remove the under-hood fuse/relay box (see DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE) ).
Disconnect under-hood fuse/relay box (relay control module part) connector B, C, D, E, F and G.
NOTE: All connector views are wire side off female terminals.

Fig 2: Identifying Under-Hood Fuse/Relay Box Connectors
Courtesy of AMERICAN HONDA MOTOR CO., INC.

With the connectors still disconnected, 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 10.

Cavity	Wire	Test Condition	Test: Desired result	Possible cause if desired result is not obtained
C1 E10	YEL LT BLU	Under all conditions	Connect battery power to terminal C1, and connect E10 to body ground with a jumper wire: The headlights (low beam) should come on.	Poor ground (G201, G301) or an open in the ground wire An open or high resistance in the wire Faulty HID unit Blown bulb Faulty headlight low beam relay Faulty under-hood fuse/relay box Faulty relay block in the under-hood fuse/relay box
G1	BLU	Under all conditions	Connect battery power to the terminal G1: The left daytime running light should come on.	Poor ground (G301) or an open in the ground wire Blown bulb An open or high resistance in the wire
G2	WHT	Under all conditions	Connect battery power to the terminal G2: The right daytime running light should come on.	Poor ground (G201) or an open in the ground wire Blown bulb An open or high resistance in the wire
G3	RED	Under all conditions	Connect battery power to the terminal G3: The left headlight (high L beam) should come on.	Poor ground (G301) or an open in the ground wire Blown bulb An open or high resistance in the wire
G4	WHT	Under all conditions	Connect battery power to the terminal G4: The right headlight (high beam) should come on.	Poor ground (G201) or an open in the ground wire Blown bulb An open or high resistance in the wire
B1	GRY	Under all conditions	Connect battery power to the terminal B1: The right front side marker light should come on.	Poor ground (G201) or an open in the ground wire Blown bulb An open or high resistance in the wire
B2	GRY	Under all conditions	Connect battery power to the terminal B2: The left front parking light should come on.	Poor ground (G301) or an open in the ground wire Blown bulb An open or high resistance in the wire
B3	GRY	Under all conditions	Connect battery power to the terminal B3: The right front parking light should come on.	Poor ground (G201) or an open in the ground wire Blown bulb An open or high resistance in the wire
B5	GRY	Under all conditions	Connect battery power to the terminal B5: The left front side marker light should come on.	Poor ground (G301) or an open in the ground wire Blown bulb An open or high resistance in the wire
E7	PNK	Under all conditions	Connect to ground with a jumper wire: The fog lights should come on.	Poor ground (G201, G301) or an open in the ground wire An open or high resistance in the wire Blown bulb Faulty fog light relay Faulty under-hood fuse/relay box Faulty relay block in the under-hood fuse/relay box

Reconnect the connectors to the under-hood fuse/relay box (relay control module part), 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
D4	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
F1	BLU	Under all conditions	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire
C1	YEL	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Faulty under-hood fuse/relay box Faulty relay control module in the under-hood fuse/relay box
D6	WHT	Under all conditions	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire
D7	YEL	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire
B4	GRY	Combination light switch (PARKING LIGHT position) ON	Measure the voltage to ground: There should be battery voltage.	An open or high resistance in the wire Faulty under-hood fuse/relay box Faulty relay control module in the under-hood fuse/relay box

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.