Honda Civic Service Manual page 646

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 . T u r n t h e i g n i t i o n s w i t c h O N ( l l ) , a n d w a t c h t h e A B S
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.
. O p e n i n t h e w i r e b e t w e e n t h e N o . 1 0 ( 7 . 5 A ) f u s e
a n d l h e g a u g e a s s e m b l y ,
. Open circuit inside the fuse box.
Turn the ignition switch OFF.
Disconnect the ABS control unit 31P connector.
T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
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 .