2000 HONDA CIVIC Data link

t-Operation
t
ABS Control Unit
Main Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehicle
speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on the
rate of deceleration.
The ABS control unit calculates the slip rate of each wheel. and it transmits the control signal to the modulator unit
solenoid valve when the slip rate is high.
The pressure reduction control is a three-mode system, that is pressure reduction, pressure retaining and pressure intensi-
fying modes.
Self -diagnosis Funqtion
The ABS control unit is equipped with a main CPU and a sub CPU, and the CPUS check each other'
The CPUs check the circuit of the svstem.
When the CPUS detect failure, they shift to the "system down mode" or the "control inhibition mode"
The self-diagnosis can be classifield into these four categories:
O: Initial diagnosis
@: Except ABS control
@: During ABS control
@: During warning
On-board Diagnosis Funstion
The ABS control unit is connected to the data link connector {16P).
The ABS system can be diagnosed with the Honda PGM Tester.
(cont'd)
MODEABS INDICATOR LIGHTMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTE IV
DOWNONNo
operation
Drive
inhibitionOperation*rlgnition
switchOFF + ONMemory
CONTROL
INHIBITIONONNo
operalron
Drive
inhibitionOperationAutomaticMemory
*1: Except CPU failure
/
19-47

e\
t
ABS CONTROL UNIT 22P CONNECTOR
Wire side of female terminals
TerminalnumbelWirocororTerminalsignDe3cription
Volt.ge
ConditionE(lgnition Switch ON (ll)lOutput voltagolTqrminal namslterminils
RED/BLUFR-IN{Front-rightinlet)
Drives right-front inletsolenoid valve.
I-GNDriJ
ON-9ONOV
OFFAC: 3-6 V
OFF
/Connect the SCS servicq
connector IApprox. 3 V
BRNscs(Service checksignal)
Detects service check signal
{Diagnostic trouble codeindication)4-GND
SCS service connectorconnected.OV
SCS service connectordisconneded.Appro)(. 5 V
7BLU/RED(Warning
ramp)
Drives ABS indicator light (The
indicator light go€s off when
ABS control unit outputs bat-
tery volta9e),
7-GND
Indicator light ONApprox, 2 V
Indicator light OFFBattery voltage
8BLU/YELNot used.
10YEUBLKFL.OUT{Front-leftoutlet)
Drives left-front outletsolenoid valve.10-GNOON
ONOV
OFFAC:3-6 V
11RED/BLKFLIN{Front-l€ft inlet)
Drives left-front inlet solenoid11-GNDOFF
lconnect the SCS servicq
connector IApprox. 3 V
YEUBLU
FR.OUT(Front-right
outlet)
Drives right-front outlet
solenoid valve.12-GNO
l4LT BLUDLC(Data linkconnector)
Communicates withPGM Tester.Honda14.GNDApprox. 5 V
17BRNA/ELMCK
lMotor check)
Detects pump motor drivesrgnal.17.GNDPumpmotorreray
ONBattery voltage
OFFOV
19YELREDPMR(Pump motorreray,
Drives pump motor relay.
19-GND
ONONOV
OFFAC: 3-6 V
OFFponnect the SCS sewicq
connedor lApprox. 3 V
BLURR-OUT(Rear-right
outletl
Drives right-rear outlel
solenoid valve.
21-GNDuJ
ON
Pumpmotorrelay
ONOV
OFFAC: 3-6 V
OFF
lconnect the SCS servicq
connedor )Approx. 3 V
22BLKGND2(Ground 2)Ground for the ABS controluntt.22-GNDBelow 0.3 v
19-53

Connector ldentification and Wire Harness Routing
Connector or
Terminal
Number of
CavhiosLocationConnocts ioNotes
c401
c402
c403
c404
c405
c406
c407
c407
c408
c409
c410
c411
c412
c413
c414
c415
c416
c417
c418
c4l9
c420
c42'l
c423
c424
c425
c426
c427
c42A
c429
c430
c431
c432
c433
c434
c435
c431
c438
c439
'14
't4
I
I
10't2
24
16
7
o
18
20
18
7
6
I
o
4
7
8
14
1
Above under-dash fuss/relay box
Under left side ot dash
Under left sid€ of dash
Under left side of dash
Under left side of dash
Und€r left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Behind under-dash fuse/relay box
Under left side of dash
Under left side of dash
Above under-dash fuse/relay box
Under left side of dash
Under left side of dash
Above under-dash fuse/r€lay box
Under left side of dash
Under left side of dash
Under left side of dash
Behind under-dash fuse/relay box
Eehind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Under left side of dash
Under left side of dash
In the steering column cover
In the steering column cover
In the steering column cover
In the steering column covEr
Under left side of dash
Under left side of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under left side of dash
Under left side of dash
Eehind under-dash fus€/relay box
Floo. wire harness (C555)
Floor wire harness (C554)
Security system
Cruise control unit
Daytime running lights control unit
Daytime running lights control unit
Roof wire harness (C701)
Moonroof wire harness (C7l1)
Front fog light connector
Integrated control unit
Dashboard wire harness (C504)
Dashboard wire harness (C502)
SRS main harness (C802)
Data link connector
Starter cut relay
lgnition switch
Security system
Clutch switch
Clutch interlock switch
Under-dash fuss/relay box (C9191
Undor-dash fuse/r€lay box {C920)
Under-dash tuse/relay box (C922)
Under-dash luse/relay box (C914)
Under-dash fuse/rBlay box (C915)
Horn relay
Brake swilch
Windshield wiper/washer switch
Rear window wiper/washer switch
Turn signal switch
Combination lighvturn signal switch
Cable reel
lnterlock control unit
Secondary heated oxygen sensor sub-
harn€ss (C781)
Ay'T gear position switch
Shift lock solenoid
Park pin switch and Ay'T gear position
console light
Transmission control module (TCM)
Transmission control module {TCM)
Under-dash fuse/relay box {C925)
ABS
Optional
Canada
Canada
Optional
Atr
MTT
Optional
Mlf
NT
Atf
CVT
CVT
Optional
AN
Atr
G401Left kick panelBody ground, via main wire harness
Main Wir€ Harness (Loft side of da3h and floor branch): '96 - 97 models
*2:Without moonroof*4: With moonroof*5: M/T (with cruise control or for D16Y5 engine)*6: With secondary heated oxygen sensor (H02S)
23-32

Connector ldentification and Wire Harness Routing
Connoctor or
Tgrminal
Number of
CavitiesLocationConneqts toNot€s
c401
c402
c403
c404
c405
c406
c407
c407
c408
c409
c410
c411
c4't2
c413
c414
c415
c416
c417
c418
c419
c420
c421
c422
c423
c424
c425
c426
c427
c428
c429
c430
c431
c432
c433
c434
c435
c437
c438
't4
l4
8,
1
10
12
24
7
6
18
20
18
7
6
8
7
8
14
2
Above under-dash fuse/relay box
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Behind under-dash fuss/relay box
Under left side of dash
Under left side of dash
Above under-dash fuse/relay box
Under left side of dash
Under-dash relay box
Above under-dash fuse/relay box
Under left side of dash
Under left side of dash
Under left side of dash
Eehind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/rslay box
Behind under-dash fuse/relay box
Under-dash relay box
Under left side of dash
In the steering column cover
In the steering column cover
In the steering column cover
In the steering column cover
Under left side of dash
Under left side of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under left side of dash
Under left side of dash
Floor wire harness (C555)
Floor wire harness (C554)
Security system
Cruise control unit
Daytime running lights control unit
Daytime running lights control unit
Roof wiro harness (C7011
Moonroof wire harness (C711)
Front fog light connector
Integrated control unit
Dashboard wire harness (C504)
Dashboard wire harness (C502)
SRS main harness (C802)
Data link connector
Starter cut relay
lgnition switch
Security system
Clutch switch
Clutch inlerlock switch
Under-dash fuse/relay box (C919)
Under-dash fuse/relay box (C920)
Under-dash fuse/relay box (C922)
Under-dash fuse/relay box (C914)
Under-dash fuse/relay box (C915)
Horn relay
Brake switch
Windshield wiper/washer switch
Rear window wiper/washer switch
Turn signal switch
Combination light/,turn signal switch
Cable reel
lnterlock control unit
Secondary heated orygen sensor sub-
harness (C781)
Ay'T gear position switch
Shift lock solenoid
Park pin switch and Aff gear position
console light
Transmission control module (TCMI
Transmission control module (TCM)
ABS
Optional
Canada
Canada
Optional
M
MIT
Optionsl
MlT
Alr
NT
NT
CVT
CVT
G401Left kick panelBody ground, via main wire harness
Main Wire Harn€ss {Left side ot dash and floor branchl: '98 model
*2: Without moonroof*4:With moonroof*5: M/T (with cruise control or for D16Y5 engine)*6: With secondary heated oxygen sensor (H02S)
23-34

Connector ldentification and Wire Harness Routing
Connosto! ol
Tsrminal
Number of
CavitiesLocationConnoqtg toNotes
c401
c402
c403
c404
c405
c406
c407
c407
c408
c409
c410
c411
c412
c4'I3
c4't4
c415
c416
c417
c418
c419
c420
c42l
c422
c423
c424
c425
c426
c427
c428
c429
c430
c431
c432
c433
c434
c435
c447
c448
c449
c450
c451
20
4
14
I
6
1
10
12
24
16
4
7
6
2
18
20
18
7
4
8
o
7
8
14
22
18
Above under-dash fuse/relay box
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Behind under-dash fuse/relay box
Under left side of dash
Under left side of dash
Above under-dash fuse/relay box
Under left side of dash
Under-dash relay box
Above under-dash fuse/relay box
Under left side of dash
Under left side of dash
Under left side of dash
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Behind under-dash fuse/relay box
Under-dash relay box
Under left side of dash
In the steering column cover
In the steering column cover
In the steering column cover
In the steering column cover
Under lett side of dash
Under left side of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under middle of dash
Under left side of dash
Under left side of dash
Under middle of dash
Under left side of dash
Under left side of dash
Floor wire harness (C555)
Floor wire harness (C554)
Security system
Cruise control unit
Daytime running lights control unit
Daytime running lights control unit
Roof wire harness (C701)
Moonroof wire harness {C711)
Front fog light connector
Intagrated control unit
Dashboard wire harness (C504)
Dashboard wire harness (C502)
SRS main ha.ness (C802)
Data link connector
Starter cut relay
lgnition switch
Security system
Clutch switch
Clutch interlock switch
Under-dash fus€/relay box (C919)
Under-dash fuse/relay box (C920)
Under-dash fuse/relay box (C922)
Under-dash fuse/relay box (C914)
Under-dash fuse/relay box (C915)
Horn relay
Brake switch
Windshield wiper/washer switch
Rear window wiper/Washer switch
Turn signal switch
Combination light/turn signal switch
Cable reel
lnterlock control unit
Secondary heaied oxygen sensor sub-
harness (C781)
A/T gear position switch
Shift lock solenoid
Park pin switch and A,/T g€ar position
console light
Security system
Security system
IVT gear position indicator trim light
Security system
Keyless door lock control unit
ABS
Optional
Canada
Canada
Optional
At-|.
M/T
Optional
M/T
Atr
Optional
Optional
Optional
Atr
AIT
AJ-|.
G401Left kick panelBody ground, via main wire harness
Main Wire Halness lLoft side of dash 8nd lloor branchl: '99 - 00 mod€ls
*2: Without moonroof*4: With moonroof*5: M/T (with cruise control or for Dl6Y5 engine)*6: With secondary heated oxygen sensor (H02S)
23-36

(l'-
Fuse NumberAmpswire ColorComponent(s) or Circuitlsl Protect€d
4180APower distribution
4240AWHT/BLKTo ignition switch (BAT)
437.5 AWHT/REDCeiling light, data link connector, trunk light
4415 AWHT/BLKPGM-Fl main relay
Not used
4640AWHT/BLUPower window motors (via power window relay)
477.5 AWHT/BLUAudio unit, clock, TCM (CVT), ECM/PCM (VBU)
4830AWHTNo.33 (7.5 A) fuse, To combination light switch (headlight)
49Not used
5030AWHT/GRNRear window defogger (via rear window defogger relay)
cl20AWHT/GRNPower door lock control unit, moonroof motor
15 AWHT/GRNHorn system, brake lights, brake signal
10 AWHT/BLKHazard warning light, turn signal/hazard rclay
54404WHT/REDOption {+B)
5540ABLU,A/VHTBlower motor (via blower motor relay)
204WHTCondenser fan motor (via condenser fan relay)
REDl'lc compressor clutch (via IVC compressor clutch relay)
204BLVBEDRadiator fan motor (via radiator fan relay)
23-6

Description
)
The sRS is a safety device which, when used in coniunction with the seat belt, is designed to help protect the driver land
front passenger) in a frontal impact exceeding a certain set limit. The system consists of the sRS unit {including safing
sensor and impact sensor), the cable reel, the driver's airbag (and front passenger's airbag)
FRONT PASSENGEB'SAIRAAG
DRIVER'S AIRBAG
CABLE REEL
SRS UNtT
t
Operation
The main circuit in the SRS unit senses and judges the force of impact and, if necessary, ignites the inflator charge(s) lf
battery voltage is too low or power is disconnected due to the impact, the voltage regulator and the back-up power clrcult
resoectivelv will keep voltage at a constant level.
For the SRS to operate:
(1) The impact sensor must activate. and send electric signals to the mlcroprocessor'
(2) The microprocessor must compute the signals' and must send signals to the airbag inflator(s)'
{3) The inflator(s) must ignite and deploy the airbag(s)'
_"-_-l
Ir3B!#h i
!.. I
ffi,*
Self-diagnosis System
A self-diagnosis circuit is built into the SRS unit; when the ignition switch is turned ON (ll), the SRS indicator light comes
on and goes off after about six seconds if the system is operating normally
lf the liglt does not come on, or does not go off after six seconds, or if it comes on while driving, it indicates an abnormal-
ity in the system. The system must be inspected and repaired as soon as possible
For better serviceability, the memory will store the cause of the malfunctlon, and the data link circuit passes on the infor-
mation from the memory to the data link connector (DLC). This intormation can be read with the Honda PGM Tesler con-
nected to the DLC (16P).
l,
24-5

Circuit Diagram
UNDER-HOOD FUSE/RELAY 8OXIGNITIONSWITCH
WHT/8LI( +WHT
Brake systsm light
passenger's airbag
l----ltlI DUMMY II BESISTOR I
tll
tl
la rl
MEMORY ERASESIGNAT IMES)CONNECTOR I2P)
GRY{GRN)
I
BRN BRN
tl.-l- .-r-\./ \./
ECM/PCM SERVICECHECKCONNECTOR
ILT 8LU
I
t'7
DATA LINKCONNECTOR{DLC) {r6P)
GRY GRY(GRN) IGNN)
V:
G801
Teminalside oi thal€ terminals
24-6
4''
SRS UNIT TERMINALSG40tG402
SBS INDICATOR CIRCUIT{ln the gauge assembly)
PGM_FI
DRIVER'SAIRBAGINFLATOR
10 14 r 13 6 7(VAl 3{VBlSRS UNIT16 17 t5 9 18 8