Honda Civic. Manual — part 626

Fig. 15: Checking Continuity Between No 1 Terminal Of Headlight (High
Beam) 2P Connector And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Faulty MICU; replace the under-dash fuse/relay box.

NO - Repair an open in the BLK wire or poor ground (G201-right side, G301-
left side).

MICU INPUT TEST

NOTE:

The MICU turns on the headlights (high beams) in a
dimming mode for the Daytime Running Lights under
the following conditions:

With the ignition switch ON (II)

The headlight switch OFF

The parking brake is released (parking brake switch
OFF)

The DRL indicator will come when one of the headlight
(high beams) bulbs is blown, or if the high beam wiring
has an open circuit with the daytime running lights ON.

For Canada models: If the vehicle is equipped with an
optional remote control engine start system, the
daytime running lights will not function when started
with the remote start.

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Exterior Lights - Civic (All Except Hybrid)

1. Before troubleshooting the lighting system, troubleshoot the B-CAN System

Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM
DIAGNOSIS TEST MODE A ).

2. Check the No. 12 (10 A), No. 13 (10 A), No. 15 (7.5 A), No. 16 (10 A), No. 17

(10 A), No. 18 (20 A), No. 19 (15 A), and No. 21 (20 A), and No. 37 (7.5 A)
fuses in the under-dash fuse/relay box. If any fuse is blown, replace it and go to
step 3.

3. Disconnect the under-dash fuse/relay box connectors E, F, G, S, and T.

Fig. 16: Identifying Under-Dash Fuse/Relay Box Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. Inspect the connector and socket terminals to be sure they are all making good

NOTE:

All connector views are shown from wire side of female
terminals.

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Exterior Lights - Civic (All Except Hybrid)

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.

5. With the connector still disconnected, make these input tests at the appropriate

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.

MICU INPUT TEST (CONNECTOR DISCONNECTED)

Cavity Wire

Test

condition

Test: Desired result

Possible cause

if result is not

obtained

E19 RED

Under all
conditions

Connect battery power to the E19
terminal: The taillights, rear side
marker lights, and license plate
lights should come on.

Poor ground
(G701)

Blown bulb

An open in
the wire

F3

RED

Under all
conditions

Connect battery power to the F3
terminal: The right front side
marker/parking light should come
on.

Poor ground
(G201)

Blown bulb

An open in
the wire

F4

GRN

Under all
conditions

Connect battery power to the F4
terminal: The right headlight (high
beam) should come on.

Poor ground
(G201)

Blown bulb

An open in
the wire

F22 WHT

Under all

Connect battery power to the F22
terminal: The right headlight (low

Poor ground
(G201)

Blown bulb

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Exterior Lights - Civic (All Except Hybrid)

6. Reconnect the connectors to the under-dash fuse/relay box, and make these

input tests at the 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.

MICU INPUT TEST (CONNECTORS DISCONNECTED)

conditions beam) should come on.

An open in
the wire

G5

RED

Under all
conditions

Connect battery power to the G5
terminal: The left front side
marker/parking light should come
on.

Poor ground
(G301)

Blown bulb

An open in
the wire

G15 PNK

Under all
conditions

Connect battery power to the G15
terminal: The left headlight (high
beam) should come on.

Poor ground
(G301)

Blown bulb

An open in
the wire

G17 PUR

Under all
conditions

Connect battery power to the G17
terminal: The left headlight (low
beam) should come on.

Poor ground
(G301)

Blown bulb

An open in
the wire

Cavity Wire

Test condition

Test: Desired result

Possible cause if

result is not obtained

G2

ORN

Under all
conditions

Check for voltage
between G2 terminal
and body ground:
There should be

Blown No. 23 (10
A) fuse in the
under-hood
fuse/relay box

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Exterior Lights - Civic (All Except Hybrid)