1996 HONDA CIVIC unit test

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Kickback
1. The motor operates when the ABS is functioning, and the fluid in the reservoir is forced out to the master cylinder
causing kickback at the brake pedal.
2. TheABScontrol unit operates the solenoid valve when the brake pedal is released afterthe initial diagnosis Youmay
hear the faint solenoid valve operation sound at this time. but it is normal.
Pump Motor
1. The pump motor operates when the ABS is functioning
2. The ABS control unit checks the pump motor operation during acceleration. You may hear the faint operation sound
at this time. but it is normal.
Brake Fluid Replacament/Air Blsading
1. Brake fluid replacement and air bleeding procedures are the same as for conventional brakes
Troubleshooting
1. The troubleshooting flowcharts explain the procedures on the assumption that the cause of the problem is still pre-
sent and the ABS indicator light is still on.
Note that troubleshooting following the flowchart when the ABS indicator light does not come on can result in incor-
rect judgment.
2. Ouestion the customer about the conditions when the problem occurred, and try to reproduce the same conditions
for troubleshooting.
self,diagnosis is made at various times such as the initial diagnosis, except ABS control. during ABS control, during
acceleraiion, during the specified vehicle speed, etc. Therefore, the symptom cannot be checked unless the check
conditions match with the problem conditions
3. When the ABS indicator light does not come on during the test drive, but the troubleshooting is performed based on
the DTC, check for the loose connectors. poor contact of the terminals, etc, before troubleshooting.
4. After troubleshooting, erase the DTC and test-drive the car. Be sure that the ABS indicator light does not come on.
5. The connector illustrations show the female connectors with a single outline and the male connectors with a double
ouflrne.
6. The connector terminal cavities containing female terminals are always numbered by looking at the connector from
the wire side. and the cavities containing male terminals are always numbered by looking at the connector from the
terminal side.
r'
19-55

Diagnostic Trouble Code (DTCI
Diagnostic Trouble Code {DTC) Indication
NOTE: This operation can also be carried out with the Honda pGM Tesrer.
l connect the scs service connector to the service check connector inside the passenger,s side kick panel.
2. Turn the ignition switch ON (||). but do not start the engine.NOTE: Do not depress the brake pedal when turning the ignition switch.
3 Record the brinking frequency of the ABS indicator right. The brinking frequency indicates the DTc.
4, Turn the ignition switch OFF, and remove the SCS service connector.NorE: The Mslfunction Indicator Lamp (MlL) will stay on after the engine is started if the scs service connector isconnected.
5. Erase the DTC.
Condhions for DTC indication. The vehicle is stoDDed.. The SCS service connector is connected before the ignition switch is turned ON fll).. The brake pedal is released.. Th€ SCS service connector remains connected during this procedure
The DTG indication stops 8nd the ABs conltol unit executes the softwaro tunqtion if at least one of the following condi-tions b satisfied:
o The vehicle is not stoDoed.' The ABS control unit receives the normat signal (which is for the ABS controt unit) from a Honda pGM Tester.. The SCS service connector is disconnected during this procedu.e,
u.s.A.
@
CANADA
@
SERVICE CHECKCONNECTOR {2PISCS SERVICE CONNECTOR07PAZ - 0010100
ABS INDICATOR LIGHT
DTC : 3 3
A8S INDICAIOR LIGHT
Snilion swirch
' when the ignition switch is turned oN (ll), the ABs indicator light comes on to check the bulb. Do not count it as a DTc.o The ABS control unit can memorize any number of DTCs.. The new DTC is not memorized when the ABS control unit has already memorized the same DTC,.lftheDTCisnotmemorized,theABSindicatorlightstaysONafteritgoesofffor3.6seconds.
19-56

LJDTG Erasure
1.
2.
Connect the SCS service connector to the service check connector inside the passenger's side kick panel.
Depress the brake pedal.
Turn the ignition switch oN (ll) while holding the brake pedal, but do not start the engine. The ABS indicator light
goes off after two seconds.
After the indicator light goes off, release the brake pedal The indicator lightcomeson after four seconds
After the indicator light comes on, depress the brake pedal again. The indicator light goes off again after four sec-
onds. The brake pedal is still depressed.
4.
5.
\t
6. After the jndicator light goes off, release the brake pedal again'
7. After four seconds, the indicator light blinks twice for 0 3 second and the DTC is erased
8. Confirm the DTC indication, and check that the DTC was erased
NOTE: Always maintain these steps. lf you disconnect the scs service connector and/or fail to operate the brake pedal
according to the indicator light indication, the DTC will not be erased
Conditions for DTC erasure
o The vehicle is stopped.
. The SCS service connector is connected before the ignition switch is turned ON {ll)
. The brake pedal is depressed before the ignition switch is turned ON (ll)'
. The SCS service connector remains connected during this procedure
The DTC erasure stops and ABS control unit executes the software lunction it at least one ot the following conditions is
satisfied:
o The vehicle is not stopped.
. The SCS service connector is disconnected during this servace'
.TheABscontro|unitreceivesthenormaIsigna|(whichisfortheAEscontro|unit)fromaHondaPGMTester'
. The brake pedal is not operated according to the indicator light indication
. The DTC erasure is finished
ABS INDICATOR LIGHT
OFF
DEPRESS
BRAKE PEDAL
RELEASE
0.3sec
lqnition switchoN (I)
J
19-57

Troubleshooting
Wheel Sensor
Diagnostic Trouble Gode {DTC) ll-18: Wheol S€n3ol DiagnosisNoTE: The ABS indicator light comes on when only the drive wheels are turning, signal disturbance is detected, etc. Therefore,test-drive the car at a speed of 12 mph (20 krn/h) or more after turning the ignition:witch from OFF to ON fll), and if the ABSindicator light does not come on, the svstem is OK.
0TcAppropriate Terminal(0)srDE11) SrD€r 1, 12 (Right-front)No.8: FRoNo.21: FRI13, 14 (Left-front)No. 10: FLoNo.23: FL115, 16 {Right-rear)No. {: RRoNo. 17: RRl17, 18 (Left-rear)No.6: RLoNo. 19: RLI
RLl (LT BLU}FRl (GRN/BLKI
Wire side ol female terminals
NO
NOTE:. Normal voltage: Approx.2 V' 0 V: Replace the ABS controt unit.. 4 V or more indicates a short to power.
A8S CONTROL UNIT 26P CONNECTOR
RRO
IBLU/YELI
RR1 IGRN/YELIFL1 IGRN/ORN}
- With the ignition switch ON{ll), ABS indicator tighr doe.noi go off,- Aftsr driving, ABS indicatotlight comes on.- With the SCS so.vice connac-tor conn€c,ted {soe pege 19-561,DTCs 11-18 a.e indicrted.
Chock lhe wheol sensor ci.cuit:1. Disconnect the ABS controlunit 26P connector.2. lleasure the resistancebetween the appropriate wheelsensor (0) and (1) circuit termi,
. Reprir op€n in the l0l or {0 cir-cuit wiro, or shon to thc {01 cir-cuit wi.o in thc {11 circuit wircbctween ths ABS control unitand approprieto wheel a6nsor.. R.pl.ce th€ epp.opri.te wheal3€nloa.
ls the resistance OK?
/Frontr 750 - 1050 o/20"C, 68.F \\Rear: 850- 1150 O/20.C, 68"F /
Check toru short to body groundin the wheel senso. circuit:Check for continuity between theABS control unit 26P connectorappropriate wheel sensor (0) circuit terminali and body ground.
. Rapair short to body ground inth6 (0) or lll cilcuit wi..bctwa.n th6 ABS control unitand appropdaie whoel lonsor.. Rep|'c6 tho appropriatc whcelsanlor.
Chock tor a sho.t to powe. in thowheel3en3or circuit:1. Reconnect the ABS control unit26P connector,2. Start the engine.3. Measure the voltage betweenthe ABS control unit 26P con-nector appropriate wheel sen-sor (0) circuit terminal andbody ground.
Ropair rhon to powo. in the l0lor lll circuit wire batw.en th€ABS cont.ol unit and .pplopriatawhccl !€naoa,
ls there 4 V or more?
fio page 19-65)
19-64

Troubleshooting
Central Processing Unit (CPUI
Diagnostic Troublo Code IDTC) 81: CPU Disgnosis
- With the ignition switch ON{lll. ABS indicator light doesnot go oft.- With tho SCS servi@ connec-tor conn€cted lsee page 19{6},DTC 81 is indicated.
P.oblem vedfication:1. Erase the DTC.2. Test-drive the vehicle.3. Make sure that the ABS indi,cator light comes on and DTC81 is indicated.
ls DTC 81 indicated?R€pllc6 th. ABS control unh.
The system k OK rt this time.
19-74

Heater and Air Conditioning
Heater '.'..""" 21'1
Air Conditioning ......."'.. "' 22-1
SUPPLEMENTAL RESTRAINT SYSTEM (SRS}
The civic sRs includes a driver's airbag located in the steering wheel hub ln addition, all models (except some
models for canada) have a passenger's airbag located in the dashboard above the glove box'
Information necessary to safely service the sRS is included in this service Manual ltems marked with an asterisk (*)
on the contents page include, or are located near, sRs components. servicing, disassembling or replacing these
items will require special precautions and tools, and should therefore be done by an authorized Honda dealer'
@-";;il rendsring the SRS inoperative, which could lead to personal iniury or deaih in the svent of a sev€re
frontal collision. all SRS service work must be pertormed by an authorized Honda d€aler'
. lmploper service procedures, including incorrest removal and instsllation of the sRs, could lead to personal
iniury caused by unintentional deployment of the airbags'
o Do not bump the SRS unit. Otherwise. the system may fait in case of a collision. or the airbags may deploy
when the ignition switch is ON {ll}'
. sRs electrical wiring harncsses are id€ntified by yellow colol coding. Related components ale located in lhe
steering column, front console, dashboard, dashboald lowet panel, and in the dashboard above the glove box'
Do not use electricaltest equipment on these circuits.

Heater
lllustrated Index
'96 - 98 Models ................................ 21'2
'99 - 00 Models ................................ 21'3
Circuit Diagram
'96 - 98 Models .....21-4
'99 - 00 Models ................................ 21-5
Troubleshooting - '96 - 98 Models
Symptom Chart ............................... 21-6
Heater Control Panel Input/
Output Signals ..............,.............. 21-7
Flowcharts
Blower Motor Speed ................... 21-8
Bf ower Motor ,...21'10
Mode Control Motor ............... ,.'.' 21-13
Recirculation control Motor ....... 21-16
Heater Control Panel ................ ... 21 -14
Troubleshooting - '99 - 00 Models
Symptom Chart ............................... 21-19
Seff-diagnosis Function ............,,,.... 21-20
Flowcharts
Air Mix Control Motor ......,.......... 21-21
Mode Control Motor ............... ..... 21 -25
Recirculation Control Motor ....... 21-27
Bf ower Motor Speed .............. .....21'29
Bf ower Motor ....21-31
Heater Control Panel ................,.. 21-35
Heater Control Panel Input/
Output Signals ............................. 21-36
Blower Unit
Repf acement .........21-37
Overhaul ................ 21-38
* Heater Unit
Replacement ....'....21-39
overhaul """" """' 21-4'l
Heater Control Panel
Repfacement .........21'42
Overhaul -'96 - 98 Models ........... 21-43
Temperature Control
Adjustment - '96 - 98 Models """" 21-44
Adiustment - '99 - 00 Models .......21-45
Air Mix Control Motor
Test - '99 - 00 Models ...........' .......21'46
Replacement - '99 - 00 Models ....21'46
Mode Control Motol
Test ................, .,...'.21'47
Replacement '.'."...21-47
Recirculation Control Motor
Test ................. .......21-48
Repf acement ......." 21-48
Relays
Test ................. .......2'l-49
Heater Fan Switch
Test - '96 - 98 Models ............. .......21-49
Mode Control Switch
Test -'96 - 98 Models ..........."....... 21-50
Power Transistor
Test - '99 - 00 Models ....'........ ....".21-50
*: Read SRS Drecautions before working in this area.

lllustrated Index
'96 - 98 Models
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS
section {24) before performing repairs or service.
BLOWER UNITReplacement, page 21-37Overhaul, page 21-38
HEATER UNITBeplacement, page 21-39Overhaul, page 21-41BLOWERRESISTOBTest,
CONTROL MOTORTest, page 21-48Replacement, page 21'48
a/c swtTcH{wirh A/c)
MOO€MOTORTest, page 21 47Replacement, page 21'47
AIR MIX CONTROL CABLEAdjustment, page 2'1-44Replacement, page 21'43
HEATER FANswtTcHTest, page 2l'49
MODEHEATER CONTBOLPANELswrTcHEsTest, page 21 50Rgplacement, page 2'l-42Overhaul, page 21-43
TEMPERATURE CONTROLLEVERAdiustment, page 21 44
Detroster-aqtivated A/C System
Turning the defroster on activates the A,/C and sets the air flow mode to FRESH. lt is possible to turn the A,/C off or to
change the air flow to RECIRCULATE by pressing the A/C bunon or the FRESH/RECIRCULATE button.
21-2