Brake Booster InsPection
FunctionalTest
1. With the engine stopped, depress the brake pedal
several times to deplete the vacuum reservoir, then
depress the pedal hard and hold it for 15 seconds lf
the pedal sinks' either the master cYlinder is
bypassing internally, or the brake system (master
cylinder. lines. modulator, proportioning control
valve, or caliPer) is ieaking.
2. Start the engine with the pedal depressed lf the
pedal sinks slightly, the vacuum booster is operating
normally. lf the pedal height does not vary, the
booster or check valve is faultY.
3. With the engine running. depress the brake pedal
lightly. Apply just enough pressure to hold back
automatic transmission creep. lf the brake pedal
sinks more than 25 mm (1.0 in.) in three minutes,
the master cvlinder is faulty. A slight change in
pedal height when the A'lC compressor cycles on
and off if normal. (The A/C compressor load
changes the vacuum available to the booster')
Leak Test
1. Depress the brake pedal with the engine running.
then stop the engine. lf the pedal height does not
vary while depressed for 30 seconds, the vacuum
booster is OK. lf the pedal rises. the booster is
faulty.
2, With the engine stopped, depress the brake pedal
several times using normal pressure When the
Dedal is first depressed, it should be low On con-
secutive applications, the pedal height should grad-
uallv rise. lf the pedal position does not vary, checK
the booster check valve.
l./
19-23
Booster Check Valve Test
1. Disconnect the brake booster vacuum hose at the
booster.
2. Stan the engine and let it idle. There should be vac-
uum. lf no vacuum is available, the check valve is
not working properly. Replace the brake booster
vacuum hose and check valve, and retest.
BRAKE BOOSTERVACUUM HOSE(Check valve
built-in)
Troubleshooting Precautions
ABS Indicator Light
I The ABS indicator light comes on when the ABS control unit detects a problem in the system. However, even thoughthe system is normal, the ABs indicator light can come on, too, under the following conditions. To determine theactual cause of the problem, question the customer about the problem, taking the following conditions into consider-ation.
. Signal disturbance
. Wheel soin
. Only drive wheels rotate. Battery voltage fluctuates
2. When a problem is detected and the ABS indicator light comes on, the indicator light can stay on untat the ignitionswitch is turned off, or it can automatically go off, depending on the mode.. Lightstayson until the ignition switch isturned off;When the system is inthesvstem down mode.o Light automatically goes off:When the system is in the control inhibition mode.(refer to symptom-to-system chart)3 The ABS indicator light stays on when the system is reactivated without erasing the DTC, but it goes off after startingthe car.
when the wheel sensor system is faulty and the ABS indicator light comes on, the algorithm of the system automaticallyturns off the ABS indicator light after the wheel speed signal returns to the normal speed. while, when the DTC is erased,the CPU is reset and the ABS indicator light goes off when the system check€d out normal by the initial diagnosis.Therefore, test-drive the car after servicing the wheel sensor system, and be sure that the ABS indicator light does notcome on.
4. When the ABS control unit outputs battery voltage to the gauge assembty, the ABS indicator light goes off.
Diagnostic Trouble Code (DTC)
1. The diagnostic trouble code (DTC) is memorized when a problem is detected and the ABS indicator light does not gooff, or when the ABS indicator light comes on.The DTC is not memorized when the ABs indicator right comes on unress the cpU is activated.2. The memory can hold any number of DTCs. However, when the same DTc is detected twice or more, the later one iswritten over the old one.
Therefore. when the same problem is detected repeatedly, it is recorded as one DTC.3. The DTCS are indicated in the order of ascending number, not in the order thev occur.4. The DTCS are memorized in the EEpROM {non-volatile memorv}.Therefore, the memorized DTCS cannot be canceled by disconnecting the battery. perform the specified orocedures toerase.
Solf-diagnosis
1. The self-diagnosis can be classifield into these four categories:' Initial diagnosis; Performed right after the engine sta rts and untiltheABs indicator light goes off.o Except ABS control: Performed when the ABS is not functioning,. During ABS control: Performed when the ABS is functioning.. During warning: Performed when the ABS indicator light is ON.2 The system performs the following controls when a problem is detected by the self-diagnosis:. ABS indicator light ON. Memory of DTC
. Mode change to the "system down mode,, or the "control inhibition mode,,.
MODEABS INDICATOR LIGHTMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTEM
DOWNONNo
operal|on
Drive
inhibitionOperation+rlgnition
switchOFF - ONMemory
CONTROL
INHIBITIONONNo
operat|on
Orive
inhibitionOperationAutomaticMemory
*1: Except CPU failure
19-54
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
The ABS indicator light does not go off after the engine is started.
- With engine running, ABSindicator light is ON.- With tho SCS sewice connec-to. connected l3oe page 19-561,no DTC is indicated,
Checkthe RR DEF RLY {7.5 A)tusein the under-dash fuse/relay box.
Raphco tha furo and rochack.
Check the ABS +B (20 A) fuse inthe under hood tuse/relay box.
R6pl.ce tho tu3c lnd r.ch.ck.
Chock for an open in the lG2 cir-GUrt:1. Turn the ignition switch ON (lt).2. Measure the voltage betweenthe ABS control unh 26P con-nector terminal No. 3 andbody ground.
Bopair opcn in tha wir. botw.cnth. RR DEF RLY 17.5 Al tus. .ndABS control unit.
Check tor an opon in thG Bl end82 circuit:Measure the voltage betweenbody ground and terminals No. 14and No. 15 individually.
Rrpair opsn in tha wiro t atwa,anthe ABS +B (20 Al fu.r .nd ABScontrol unh.
ls there banery voltage?
1To page 19-63)
ABS Indicator Light Does Not Go Off
YES NOTE: Feinstattthe luse it it is OK.
YES NOTE: Reinsta
the fuse if it is OK.ABS CONTROL UNIT 26P CONNECTOR
IG2IELK/BLUI
Wire side of female terminals
ABS CONTBOL UN]T 26P CONNECTOR
8T IWHT/GRNI
Wire side of temale terminals
19-62
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
Solenoid
Diagnostic Trouble Code {DTC} 31-38: Solenoid Diagnosis
YES
ABS CONTROL UNIT 22P CONNECTOR
Wire side of female terminals
ABS CONTROL UNIT 26P CONNECTOR
FL.OUT (YEL/ALK)- With the ignition switch ON(lll, ABS indicator light doesnol go oft. or ABS indic.to.light comes on while ABS i3functioning.- With the SCS servico connec-tor connected ls€. pag€ 19-561,DTCa 31-38 are indicstod.
Check for a short lo powor in thosol6noid circuitl1. Disconnect the ABS controlunit 22P and 26P connectors.2. Sta rt the engine.3. Measure the voltage betweenthe ABS control unit connectorappropriate solenoid circuitterminal* and body ground.
Ropri. short to powor in thcappropriate solanoid ci.cuit wirobotw6.n ths ABS cont.ol unitand modulrtor unit.
ls there battery voltage?
Check for a short to body groundin the 3olenoid circuit:Check tor continuity between theappropriate solenoid circuit termi-nal* and body ground.
. Repair short to body ground inlhe .ppropriato solonoid circuitwire betwoan th6 ABS controlunit and modllato. unit.. Replaco the modul.tor unit.
Check th€ ABS control unit:'1. Turn the ignition switch OFF.2. Connect the ABS control unit22P and 26P connectors.3. Connect the SCS service con-
4. Turn the ignition switch ON {ll}.5. Measure the voltage betweenthe ABS control unit 26P con-nector appropriate CONI circuitterminal++ and body ground.
Check for loos€ ABS control unhconnectora. It naceslrry, aub3ti-tutc . known-good ABS controlunit tnd recheck.
ls there approx. 3 V?
DTCAppropriateConnectorAppropriateTerminal
31: FRJN22PNo. 1
32: FR-OUT22PNo.12
33i FL'IN22PNo. 11
34: FL OUT22PNo.10
3s: RRIN26PNo.13
36: RR-OUT22PNo. 21
37: RLIN26PNo.25
38: RL-OUT26PNo.12RL.OUT IYEL}
Wire side of female terminals
DTCAppropriateTerminal
31: FR-lNNo. 2: SCOM
32: FR-OUTNo. 2: SCOM
33i FLINNo. 1: rcOM
34: FL-OUTNo. l: PCOM
35: RR{NNo.1:PCOM
36: RR-OUTNo. 1: rcOM
37rRL'lNNo. 2: SCOM
38: RL-OUTNo. 2: SCOM
RL.OUT (YEL}
19-66
(To page 19-671
lgnition Voltage
Diagnostic Trouble Code (DTC) 61: lgnhion Voltage Diagno3is
A8S CONTROL UNIT 26P CONNECTOR
IG2IBLK/BLU}
]Wire side of lemale terminals
- With tha engin€ running, ABSindicator lighl is ON.- With the SCS s€rvice connec-to. conn€ctod ls€€ page 19-561,DTC 61 is indicated.
Problem v€rification:1. Erase the DTC.2. Start the engine.3. Make sure that the ABS ind;cator light comes on and DTC61 is indicated.
ls DTC 61 indicated?The system b OK .t this time.
Check the lG2 cilcuii:Measure the voltage between theABS control unit 26P connectorterminal No. 3 and body ground.
ls there 18 V or above?
lf the vohage is 0 V, check lor anopon in the lG2 circuit.It there is 12 - 17 V. substitute aknown-good ABS colrtrol unit andJecheck.
It
19-73