2003 HONDA CIVIC Control

ABS Components
DTC Troubleshooting (cont'd)
DTC 81: CPU (Central Processing Unit)
1. Clear the DTC, then disconnect the Honda PGM
Tester.
2. Test-drive the vehicle.
Does the ABS indicator come on and is DTC 81
indicated ?
YES Replace the ABS modulator-control unit.l
NO-The system is OK at this time. t
19-52
ABS Indicator Gircuit
Troubleshooting
ABS indicator does not come on
1. Turn the ignition switch ON (ll), and watch the ABS
indicator.
Does the ABS indicator come on?
YES The system is OK at this time.I
NO Go to step 2,
Pull up the parking brake lever.
Does the btake system indicator come on?
YES Go to step 3.
NO Repair open in the indicator power source
circuit. lf necassary, substitute a known-good ABS
modulator-control unit, and recheck. I. Blown No, 10 (7.5A) fuse.. Open in the wire between the No. 10 (7.5A)fuse
and lhe gauge assembly,. Open circuit inside the fuse box.
Turn the ignition switch OFF.
Disconnect the ABS control unit 31P connector.
Turn the ignition switch ON (ll).
Does the ABS indicator come on?
YES-Check for loose terminals in the ABS control
unit 31P connector. lf necessary, substitute a
known-good ABS modulator-control unit, and
recheck.l
NO Go to step 6.
Turn the ignition switch OFF.
Remove the gauge assembly (see page 22-64).
3.
5.
6.
7.

8.
9.
Disconnect the gauge assembly connector A (22P).
Check for continuity between gauge assembly
connector A {22P) terminal No, 12 and body ground.
GAUGE ASSEMBLY CONNECTOR A (22P)
Wire side of female terminals
ls there continuity?
YES- Repair shon to body ground in the wire
between the gauge assembly and the ABS control
unit.l
NO Go to step 10.
Disconnect the gauge assembly connector B (22P).
Check for continuity between gauge assembly
connector B (22P) terminal No. 12 and body ground.
GAUGE ASSEMBLY CONNECTOR B (22PI
Wire side ol Iemale terminals
ls there continuity?
YES Check for loose terminals in the gauge
assembly connectors. lf the connectors are OK,
replace the gauge assembly.l
NO Repair open in the wire between the gauge
assembly and body ground (G501).1
'10.
11.
3.
ABS indicator does not go off
1. Checkthe No. 8 (20Alfuse in the under-hood fuse/
relay box, and reinstall the fuse if it is OK.
ls the fuse OK?
YES Go to step 2.
NO-Replace the fuse, and recheck. lf the fuse is
blown, check for a shon to body ground in this fuse
circuit. ll the circuit is OK, replace the ABS
modulator-control unit. I
Check the No. 11 (7.5A) fuse in the under-dash
fuse/relay box, and reinstall the fuse if it is OK.
ls the f use OK?
YES Go to step 3.
NO Replace the fuse, and recheck. If the fuse is
blown, check for a short to body ground in this fuse
circuit. lf the circuit is OK, replace the ABS
modulator-control unit. I
Disconnect the ABS control unit 31P connector.
Measure the voltage between terminal No. l8 and
body ground.
A8S CONTROL UNIT3lP CONNECTOR
ls there battery voltage?
YES-Go to step 5.
NO Repair open in the wire between the No. 8
(20A) fuse and the ABS control unit.l
(cont'd)
Wire side of female terminals
19-53

ABS Components
5.
6.
ABS Indicator Circuit Troubleshooting (cont'dl
Turn the ignition switch ON (ll).
Measure the voltage between the ABS control unit
31P connector termina I No. 15 and body ground.
ABS CONTROL UNIT 3IP CONNECTOR
Wire side of female terminals
Is there battety voltage?
YES-Go to step 7.
NO-Repair open in the wire between the No. 11(7.5A) fuse and the ABS control unit.I
Turn the ignition switch OFF.
Check for continuity between the ABS control unit
31P connector terminal No. 19 and body ground.
ABS CONTROL UNIT 31P CONNECTOB
Wire side ot Iemale terminals
ls there continuity?
YES Go to step 9.
NO-Repair open in the wire between the ABS
control unit and body ground (G202). t
9. Turn the ignition switch ON (ll).
1.
8.
19-54
10. Connect the ABS control unit3lPconnector
terminal No.20 and body ground with a jumper
wire.
ABS CONTROL UNIT 31P CONNECTOR
Wire side of female terminats
Does the ABS indicator go off?
YES-Check for loose terminals in the ABS control
unil 31P connector. lf necessary, substitute a
known-good ABS modulator-control unit, and
recheck.I
NO Go to step 1 1.
Remove the gauge assembly, and leave the
connectors connected. Connect the gauge
assembly connector A (22P) terminal No. '12 and
body ground with a jumper wire.
GAUGE ASSEMBLY CONNECTOR A (22P)
\'l '1.
Wire side of female terminals
Does the ABS indicator go off?
YES-Repair open in the wire between the gauge
assembly and the ABS control unit.I
NO-Check for loose gauge assembly connectors.
lf the connectors are OK, replace the printed circuit
board in the gauge assembly.l

Brake System Indicator Gircuit Troubleshooting
Brake system indicator does not come on
'1. Discon nect the m ultiplex contro I unit l3Pconnector
and the ABS control unit 31P connector.
2. Check for continuity between the ABS control unit
3l P connector terminal No,21 and bodyground.
ABS CONTROL UNIT 31P CONNECTOR
Wire side of female terminals
ls there continuity?
YES Repair short to body ground in the wire
between the multiplex control unit and the ABS
control unit.l
NO Go to multiplex control system
trou bleshooting lsee page 22''172).a
Brake system indicator does not go off
1. Turn the ignition switch ON {ll).
2. Release the parking brake.
Does the brake system indicatot go ofl after
several seconds?
YES The system is OK at this time.l
NO Go to step 3.
3. Check the brake fluid level.
ls the level OK?
YES Go to step 4.
NO Refill the brake fluid, and recheck.l
4. Check the ABS indicator.
Does the ABS indicator stay on?
YES Read the ABS DTC (see step 1 on page 19-32).
and do the applicable troubleshooting for the DTC
NO Go to step 5.
5. Turn the ignition switch OFF.
6. Disconnect the ABS control unit3lPconnector.
7. Connect the ABS control unit 31P connector
terminal No. 21 and body ground with a jumper
ABS CONTROL UNIT 31P CONNECTOR
(cont'd )
Wire srde of lemale lerminals
19-55

ABS Components
8.
9.
10.
11.
12.
13.
Brake System Indicator Gircuit Troubleshooting (cont'd)
Turn the ignititon switch ON (ll).
Check the brake system indicator.
Does the brake system indicatot go off?
YES-Replace the ABS modulator-control unit.l
NO-Go to step 10.
Turn the ignition switch OFF.
Connect the multiplex control unit 13P connector
terminal No. 'l and body ground with a jumper wire.
MULTIPLEX CONTROL UNIT 13P CONNECTOR
JUMPERWIRE
Wire side of female terminals
Turn the ignition switch ON (ll).
Check the brake system indicator.
Does the btake system indicatot go off?
YES Repair open in the wire between the
multiplex control unit and the ABS control unit.l
NO Go to multiplex control system
troubleshootin g (see page 22-17 2). a
19-56
\

ABS Modulator-Control Unit Removal and lnstallation
NOTE:. Donotspill brake fluid on the vehicle; it may damage the painU if brakefluidgetsonthepaint,washitoff
immediately with water.. Becareful not to damage or deform the brake lines during removal and installation.. To prevent the brake fluid from flowing, plug and cover the hose ends and joints with a shop towel orequivalent
malenal.
Removal
'1. Turn the ignition switch OFF.
2. Pull upthelock(A) oftheABScontrol unit3lPconnector(B),thendisconnecttheconnector.
FLARE NUTl5 N.m (1.5 kgt.m,11 lbt.ftl
6)o
CII mm NUT8.8 N.m {0.9 kgl m.6.5lbf ft)
6 mm BOLT9.8 N.m11.0 ksf.m,7.2lbf.ft)
\.
--/Q \,
\---'
(cont'd)
19-57

ABS Gomponents
ABS Modulator-Control Unit Removal and Installation {cont'dl
3. Disconnectthe six brake lines.
4. Remove the two I mm nuts.
5. Remove the ABS modulator-control unit (C).
Installation
'1. InstalltheABS modulatorcontrol unit, then tighten the two 8 mm nuts.
2. Align the connecting surface ofthe ABS control unit 3'lP connector.
3. PushinthelockoftheABScontrol unit 31P connector until you hear it click into place. then connect the connector.
4. Connect the six brake Iines.
5. Bleed the brake system, starting with the front wheels.
6. Connect the PGM Tester, and do the solenoid function test for each wheel.
7. Bleed the brake system again, staning with the front wheels.
8. Start the engine, and check that the ABS indicator and brake system indicator go off.
9. Disconnect the Honda PGM Tester. Test-drive the vehicle, and check that the ABS indicator and brake qvqtem
indicator do not come on.
19-58

Moonroof
Component Location Index
WIND DEFLECTORReplacement, page 20-38
GLASSHeight Adjustment, page 20 37Replacement, paqe 20-37Closino Force and Ooenino DraoCheck; page 20-48 "
DRAIN CHANNELReplacement, page 20-39
,5
?a<&,
@
..t'- ?.@-@c
_a
@
/,BR^CKEI
COVER
LIMIT SWITCH(AUTO.STOP SWITCH)Adjustment, page 20-46ER
I
CABLE TUBEREAR BRACKETE@
E STOP
.a'
MOONROOFCONTROL UNIT
FRAMEReplacement, page 20-42
CABLE ASSEMBLYBeplacement, page 20-44
*\
)REAR DRAIN VAI-VE
_-""-\q
Replacement, page 20'41
gJ -.- REAR DRA'N TUBE
20-35