Control Unit Input Test

Before testing, troubleshoot the multiplex integrated control system using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
Multiplex Integrated Control Unit
Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
Disconnect under-dash fuse/relay box connectors F, H and P.
NOTE: All connectors are shown from the wire side of female terminals.

Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors
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 are OK, go to step 5.

Reconnect the connectors, and make these input tests at the 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 6.

TEST CONDITION REFERENCE CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
F14 H14	BLU/RED	Ignition switch ON (II), driver's seat belt is unbuckled.	Measure the voltage to ground: There should be less than 1 V.	Faulty driver's seat belt buckle switch Poor ground (G601) An open in the wire
F14 H14	BLU/RED	Ignition switch ON (II), driver's seat belt is buckled.	Measure the voltage to ground: There should be 5 V or more.	Faulty driver's seat belt buckle switch Short to ground
P13	RED/WHT1 RED2	Ignition key in the ignition switch	Measure the voltage to ground: There should be less than 1 V.	Faulty ignition switch Poor ground (G501) An open in the wire
P13	RED/WHT1 RED2	Ignition key out of the ignition switch	Measure the voltage to ground: There should be 5 V or more.	Faulty ignition switch Short to ground

Remove the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).
Disconnect gauge control module connectors A and B.
NOTE: All connectors are shown from the wire side of female terminals.

Fig 2: Identifying Gauge Control Module Connectors
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 are OK, go to step 9.

Reconnect the connectors, and make these input tests at the connector.

If any test indicates a problem, find and correct the cause, then recheck the system.
If the input tests prove OK, go to step 10.

TEST CONDITION REFERENCE CHART

Cavity

Wire

Test condition

Test: Desired result

Possible cause if desired result is not obtained

A13

RED/WHT⁽¹⁾ RED⁽²⁾

Engine OFF

Check for continuity to ground: There should be continuity.

Engine running

Check for continuity to ground: There should be no continuity.

BLK

Under all conditions

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

⁽¹⁾	'04-05 models

⁽²⁾	'06-08 models

Perform the Gauge Self-diagnosis Function (see SELF-DIAGNOSTIC FUNCTION ).
- If the beeper sounds and the seat belt reminder light flashes, go to step 11.
- If the beeper does not sound or the seat belt reminder light does not flash, replace the gauge control module.
Substitute a known-good under-dash fuse/relay box and recheck the system.
- If the symptom is gone, the multiplex integrated control unit (MICU) is faulty; replace the under-dash fuse/relay box.
- If the symptom is still present, the gauge control module is faulty; replace the gauge control module.