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
Le
\.t
CONDITION FOR DETECTION
MANAGEI\,4ENT
FEFERTOPAGEDUNINGABS CONTFOLEXCEPTABS CONTAOL
19-60
19-62
The ABS indicator lighl cones on when vehicle is stopp€d and wheel sensor a given vohaqe does nol
19 64
The ABS indicaror comes on under th€lollowing conditions.When morethan one otwheels are a standstiland thelelocirv otthe fastest wheel reaches a
' fohen th. velocity of the faslesl wheel reaches or exceds a given sped, and it there ar€ somewh@lswhose velocity is slowe.lhan a cenain percenlage oi lh€ fast6t wheelsped for 3 given period. when rhere are lemporary open or short ctcuits ol rhe wheel sonsor' chipp€d pulser gear, orsrgnalorslJrbaaLe
19 64
The main relay repeats ON/OFF switching atalltimes.WhenthemainrelayisON,ashortt$tpulseissentloeachvalve lfthere s some dis'repa ncv, lheABS indicalor lightcomes on.. When rhe main relay is OFF, a shonl€sl pulse is s€nlto each valve lfth6 solenoid drive voltage rsout ol a qiven range, the ABS ndicalor lighl comes on19-66
'The pump nolot s activaled orc€ o' Mrce sfier every gn't'on sw'lch ON (ll) operarion whrle lte -^vchicle acLelerales lrenthemolorotivevo'taSersrhecled When lhevolla96 rs abnormar,lre Absindicaror llghl comes on.. Afte. ABS ;onl rol com pletion, the moror isswitched ofi 6nd the main CPU checks the molor dnvevoltase. when rhe vortase is abnormsl, the ABS indicato49!!!99!:l!:_-
19-68
D!rino an active motor lesl or AAS control,lhe main CPU checks ihe supplv voltage to the motor'whe;lhe vohage s abnofmal, the ABS indicator lightcomes on19,68
lirhe moror drvevoltage indicates molot operalion when the main cPU does notswilch the motoroN, rhe ABs indicaro. comes on19-64
. Wh"" " ".1"".1d ""1r. f"llure is detecred, the CPU checksth€ voltage ofthe main rel6v output lllhevohaqe is lowerthan 6 given vohage, theABS indicator light comes on. The ;ain r€lay repeats ON/OFF switching ar a!ltimss when the main rel.v is ofi, a shorl l6st pulse
is sent ro €ach valve. The CPU mon tors the reJer€nce vohage ll the vohage is out ot a g iven range'
the ABS indic.tor lightcomes on
19 71
wt'",, rt'e lgnitlon rottag" is ower or higherthan a given voltage,lhe CPU inhibils ABSlonlrolandswirches oli the ma in relaY, 6nd the ABS indicaror lig ht com€s on When the ig n ilion vohage recove'sto normal f6ng6, ABS inhibition is canceled.19.73
rimln CpU anO suU CeU ch€ck each other undercertain condnions. Whon rhe CPUS dstectthe fol'lowing discrepanaies, rhe ABS indicator light comss on. whe; rh€re is discGpancv n lhacarculated wheelspeed velocirv thar continuosJor more than a given
.i^/hen rhere is discrcoancv in the ehase informalion lhat continuesfor morerhan a given period' When rhere is discrepancY in thecalculared conlfol pa.amerer'. When thewatch dog conrrolp!lsetailslof a given penod. When th6 checkotth€ ROM tai1s.. when there is disrepancy inrhe data roading.nd wriung prcledurc ot RAM
19 7'l
tr
19-59
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
Precautions/Procedu res
Steering-related Precautions
Stesring Wheel and Cable Reol Alignment
NOTE: To avoid misalignment of the steering wheel on
reassembly, make sure the wheels are turned straight
ahead before removing the steering wheel.
Rotate the cable reel clockwise until it stops.
Then rotate it counterclockwise {approximately two and
a half turns) until the arrow mark on the cable reel label
points straight up.
24-12
:l
St€€rin9 Column Removal
CAUTION:
. Eefore removing thg stggring column. disconnect the
connsstor bqtween the cable r€el and th€ SRS msin
harness.
. lf the stoering column is going to be romoved with-
out dismounting th6 stoering wheel, lock the steer-
ing by turning the ignition key to o-LOCK position, or
remove the key trom the ignition switch so that the
steering wheel will not turn.
NOTE:
When the airbag and cable reel are disconnected,
don't reconnect the battery cable. lf the battery is
reconnected and the ignition switch is turned ON (ll),
the SRS unit will store this as an open in the driver's
airbag inflator, and the SRS indicator light will come
on.
For disconnecting the spring-loaded lock type con-
nector, refer to page 24-'10.
SRS MAIN HARNESS2P CONNECTOR
Do not replace the original steering wheel with any other
design because it will make it impossible to properly
install the airbag (only use genuine Honda replacement
parts).
After reassembly, confirm the wheels are still turned
straight ahead and that the steering wheel spoke angle
is correct. lf minor spoke angle adjustment is necessary,
do so only by adjusting the tie-rods, not by removing
and repositioning the steering wheel.
Gable Reel
Replacement
!@@ store a .emove airbag assambly with thepad surtace up. lf the airbag is improperly stored face
down, accidental deploymont could propel the unit withenough force to cause sorious iniury.
CAUTION:
. Alwsys disconnect the airbag connoctor(s) when ih€harness is disconngcted.
. Do not disassemble or tamper with the airbag.
NOTE: Carefully inspect the airbag assembly beforeinstalling it. Do not install an airbag that shows signs ofbeing dropped or improperly handled. such as dents,cracks or deformation.
l.Disconnect the battery negative cable. then discon-nect the positive cable from the battery, and wait atleast three minutes.
Remove the access panel from the steering wheel,then disconnect the 2P connector between the driv-er's airbag and cable reel.
NOTE: When disconnected, the airbag connector isautomatically shorted.
DRIVER'SAIRBAG
)
24-72
or
TORX EOLTSUse a Torx T30 bit.
DRIVEB'S DASHBOARD LOWER COVER
4.
Make sure the wheels are aligned straight ahead.
Remove the driver's dashboard lower cover.
5. Remove the two Torx bolts from the steering wheel,and disconnect the horn connector. Then removethe driver's airbag.
\
Cable Reel
Replacement (cont'd)
11.
NOTE:
. Before installing the steering wheel, the front
wheels should be aligned straight ahead.. Be sure to install the harness wires so that theyare not pinched or interfering with other parts.. After reassembly. confirm that the wheels arestill turned straight ahead and that the steeringwheel spoke angle is correct (road test). lf minor
spoke angle adjustment is necessary, do so onlyby adjusting the tie-rods, not by removing andrepositioning the steering wheel.
Set the cancel sleeve so that the projections arealigned venically.
PROJECTIONS
12. Carefully install the cable reel on the steering column shaft. Then connect the 3p connector to thecable reel sub-harness, and connect the 2p connec-tor to the SRS main harness.
. 24-74
Install the steering column covers.
lf necessary, center the cable reel. {New replacementcable reels come centered.) Do this by first rotating thecable reel clockwise until it stops. Then rotate tt counterclockwise (approximately two and a half turns) untilthe arrow mark on the cable reel label points straightup.
ARROW MARK
15. lnstall the sleering wheel, then connect the hornconneclor and cruise control sevresume switch con
14.
neclor.
STEERING WHEELCRUISE CONTROLSET/RESUM€
- How the Circuit Works
The anti-lock brake system (ABS) prevents locking
of the wheels as a result of heavy braking and/or
poor lraction. A vehicle with locked wheels cannot
be steered. The anti-lock brake system controls the
application of the brakes, allowing the driver to
maintain control of the steering.
Under anti-lock conditions, the antilock brake
system (ABS) modulates the pressure of the brake
tluid to each brake caliper. This system is a four
channel system: the pressure at each caliper is
controlled independently of the pressure al any
other caliper. Whenever a wheel is likely to lock
dunng braking, the anti-lock brake system
modulates the brake oressure at that wheel. When
the brake pressure is reduced to the point where
there is no longer any possibility of wheel locking,
the system returns to the conventional braking
system mode of operation.
Battery voltage is applied at all times through fuse
63 to the ABS control unit. When the ignition switch
is in ON (ll), battery voltage is supplied to the
control unit through fuse 16. The control unit is case
grounded. Inputs are received from the brake switch
and the individual wheel sensors located at each
wheel. The ABS control unit uses these inputs to
control the modulator solenoid unit. The solenoids
adjust the hydraulic pressure applied to each
calioer.
The ABS control unit has a self-diagnosis function.
When the control unit detects a fault, it turns on the"ABS" indicator and disables the anti-lock brake
system. lf the fault is not in the conventional braking
system, the brakes will continue to operate normally
but without the anti-lock feature.
Refer to the Service Manual (Section '19,
Anti-Lock Brake System) for specific tests or
troubleshooting procedures.
44-3