HONDA CR-V 1998 RD1-RD3 / 1.G Workshop Manual

Anti-lock Brake System (ABS)
Features/Construction
When the brake pedal is pressed during driving, the wheels can lock before the vehicle comes to a stop. In such an event,
the maneuverability of the vehicle is reduced if the front wheels are locked, and the stability of the vehicle is reduced if the
rear wheels are locked, creating an extremely unstable condition. The ABS precisely controls the slip rate of the wheels to
ensure maximum grip force from the tires, and it thereby ensures maneuverbility and stability of the vehicle.
The ABS calculates the slip rate of the wheels based on the vehicle speed and the wheel speed, then it controls the brake
fluid pressure to attain the target slip rate.
Grip Force of Tire and Road Surlace
COEFFICIENT OFFRICTION
TARGET SLIP RATE
RADIALOIRECTIONOF THEROTATIONALDIRECTION
SLIP RATE
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ABS 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 has three modes: pressure reducing, pressure retaining, and pressure intensi{ying modes.
Self-diagnosis Function
The ABS control unit is equipped with a main cPU and a sub cPU, that check each other for problems.
The CPUs check the circuit of the system.
When the CPUS detect failure, they shift to the "system down mode" or the "control inhibition mode".
The self-diagnosis can be classitied into these four categories:
O: Initial diagnosis
O: Except ABS control
O; During ABS control
@: During warning
On-board Diagnosis Function
The ABS system can be diagnosed with the Honda PGM Tester.
The ALB Checker cannot be used with this system. For air bleeding. and checking wheel sensor signals, use the Honda
PGIM Tester. See the Honda PGM Tester user's manuals for specific operating instructions.
(cont'd)
19-29
ABS CONTROL I-INIT
MODEABSINDICATOR LIGHTMAIN
RE LAY
SOLENOID
VALVERestan conditionDTC
SYSTEM
DOWNONNo
operatron
Drive
inhibitionOperation*rlgnition
switchOFF - oN (ll)Memory
CONTROL
INHIBITIONONNo
operaton
Drive
inhibitionOperationAutomaticlVemory
*1: Except CPU failure
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Anti-lock Brake System (ABS)
Features/Gonstruction (cont'd)
ABS Modulator
The ABS modulator consists of the inlet solenoid valve, outlet solenoid valve, reservoir, pump, pump motor and thedampjng chamber.
The modulator reduces the caliper fluid pressure directly. lt is a circulating-type modulator because the brake fluid circulatesthrough the caliper, reservoir and the master cylinder.The hydraulic control has three modes: pressure reduction, pressure retaining and pressure intensifying modes.The hydraulic circuit is the independent four channel-type, one channel for each wheel.
SOLENOID VALVE
t-
Pressure intensifying mode: Inlet valve open, outlet valve closed,
Pressure retaining mode:
Pressure reduction mode:
Motor operation mode:
Master cylinder fluid is pumped out to the caliper.Inlet valve closed, outlet valve closed.
Caliper fluid is retained by the inlet valve and outlet valve.Inlet valve closed, outlet valve ooen
Caliper fluid flows through the outlet valve to the reservoir.When starting the pressure reduction mode. the pump motor is ON.When stopping ABS operation, the pump motor is OFF.The reservoir fluid is pumped out by the pump, through the damping chamber, to the mastercylinder.
PUMP MOTOR
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Wheel Sensor
The wheel sensors are the magnetic contactless type. As the gear pulser teeth rotate past the wheel sensor's magnetic
coil, AC current is generated. The AC frequency changes in accordance with the wheel speed. The ABS control unit detects
the wheel sensor signal frequency and thereby detects the wheel speed
at LOW SPEED
wheel Sp€od and Modulatot Control
VEHICLE SPEED
VEHICLE SPEED
WHEEL SPEED
PRESSU
OUTLETVALVE ON
OFF
INLETVALVE ON
OFF
MOTOR
ON
OFF
When the wheel speed drops sharply below the vehicle speed, the outlet valve opens momentarily to reduce the caliper
fluid pressure. The pump motor starts at this time. As the wheel speed is restored. the inlet valve opens momentarily to
increase the caliDer fluid oressure.
F
GEAR PULSER
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Circuit Diagram
UNDFS I]OOD FISAFELAY 8OXCbsod: &rrc ped. deprelled
wHT/GrN -tjF GFrlrr'vril
GNITION
*oJG\'*"\€F*,-
UNDER-HOOD A8S FUSE/FELAY BOX3P CONNECTOR (O number)
t_--t l-|ll'"1
UNDER.HOOO A8S FUSE/RELAY BOX2P CONNECTOF (! numbor)
EFIAKE SWITCH CONNECTOR
l€-4| 1 txl2 |
f s a'lLr--'--.----1
UNDER,DASH FUSFJRELAY BOX20P CONNECTOR (O number)M-OD U LATOR UN IT CON N ECTOR
ll3 2ir I
{tT6TsF}
!]q:]j_1,
MP MOTOR CONNECTORnumber)
ATi)
PU
UNDER-DASH FUSE/RELAY BOX18P CONNECTOR (E number)
(tr
ASSEMBLY 5P CONNECTOR
----.4-l1)/l3l/l5l
356J89
10111213,/ 115 ,/19
123456
910'1213|i4 /718
19-32
Wire side ol female lerminals
Terminal side oJ lemale terminals
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ABS CONTROL I.]NII {NBK)
Gil
SEFVCE CHEC(STOP
-[rf$-n*'"[m;] t
ra
G2t
rlr*r"t_._*hr;c, ------ r"-!cc
-
Pf:-tL
t=
#
J*tt-
-
55
V-
,ln l'? g,l,BFN+BsN-,| Br(--o-.8:
Y G101cr02
WIT/BLIJ
,r-,,..J A ^ l0lTA L M|; i trr cor'hrEcroF 'r6P)
8LK
4c1013,402
tG2,
Lffi-
_-- -.^ PMR,
t!94
.,._ PCOM,
9
GRN/8I(x
,,-:gLTpliirn
Ilcrom.:C, IRE^R4iq!AGFNmL---l
BLr( -l
eli -.1
BtK-L,-ry
ABs coNTRoL uNrr 26p coNNEcroR 9E-FY!!(o;fib;;; -- coNNF
e -rlr z :ltl,/ a ,18 e tol/ 12li3l I'
| | 4 1 5 16)17 V I1s V l2' VIIU)4 p91ffi
ABS coNTRoL uNrr 22p coNNEcroR QAIA.Li-;;i,;;) -- coNNE
T
t,*---;T- =l------5o ril mtTlI r, / , | #l,'2 -14 i7 19 -)1 .221 | | ,z
Wire side of lemale terminals
)E CHECK:CTOR (2P)
,f
'97
FRO
TermmateINKcroR (16P)
?'--"r""""-./ 6 ,/ 8\
F{ c7
HEEL SENSOR CONNECTOR
model '98-99 models
NT/ REAR FRONTI RIG-HT-REAR
iTtl /J r lz !\
nal side ol Terminal side olterminals male terminals
LEFT.REAR/nf'\1./ 1F
r .4-;1V L:JTerminal side ollemale terminals
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ABS Control Unit Terminal Arrangement
ABS CONTROL UNIT 26P CONNECTOR
Wire side of female terminals
TeiminalnumbelWiiecolorTerminal3ignTeiminalnamglDescription
Voltrge
tdminalsCondhions(lgnition Switch ON llll)Output voltago
1GRNn/VHTPCOM(Primary
common)
Power source for the solenoidvalve and pump motor.1-GNDON6
ONOV
OFFAC:3-6V
2BLI(WHTSCOM(Secondary
common)
Power source for the solenoid2-GNDOFF
lConnect the SCS seNice] connector IApprox.3 V
BLVBLU(lgnition 2)Detects ignition switch 2signal. (System activate signal)3-GNDBattery Voltage
4BLUA/ELRRO(Rear-right 0)Detocts right-rear wheelsensor srgnat.When the wheel isturned at 1 turn/second.
53 mV or above ondigitaltester (ACrange) {Beference)150 mvtrp or aboveon oscilloscope
GRYRLO(Rear-left 0)Detects left-rear wheel sensorsrgnat.6-19
8GRNFRO(Fronr-right 0)Detects right-front wheelsensor signal.8-21StopsApprox.2.5 VSTOP
{Stop)Detects bfake switch signal.(Prevents unnecessary ABS operation)9-GNDBrake pedal pressed.Battery Voltage
Brake Dedal released.OV
10BRN^/VHTFLO(Front-left 0)
Detects left-front wheel sensorsrgnal.
10-23
When the wheel isturned at 1 turn/second.
53 mV or above ondigitaltester lACrange) (Reference)
150 mvpp or aboveon oscilloscope
StopsADprox. 2.5 V
YELRL-oUT(Rearleft outlet)
Drives left-rear outlet solenoid12.GNDONONOV
OFFAC:3-6V
13RED^/vHTRR.IN(Rear-right
inlet)
Drives right-rear inlet solenoid13.GNDOFF
lConnect the SCS service\ connector IApprox. 3 V
14WHT/GRNB1(Baftery 1)Power source for the solenoidvalve and pump motor.14.GND
Every timeBattery Voltage82(Battery 2)Power source for the solenoidvalve and pump motor.15-GND
16BLKGND2(Ground 2)Ground for the ABS controlunit.16-GNDBelow 0.3 V
't7GRN/YELRR1(Rear-right 1)Detects right-rear wheelsensor signal.'t7 -4
When the wheel is turnedat l turn/second,
53 mV or aboveon digitaltester(AC range)(Reference) 150mVp-p or aboveon oscilloscope
19LT BLURL1(Rearieft 1)Detects left-rear wheel sensorsignal.19-6
GRN/BLKFR1(Front-right 1)Detects right-front wheelsensor srgnat.21-8
23GBN/ORNFL1{Front-left 1}Detects left-front wheel sensorsagnal.23-10StopsApprox. 2.5 V
REDRLI N(Rear-left inlet)
Drives left-rear inlet solenoid
25,GND
ON
=
-9ONOV
AC:3-6V
OFF
/Connect the SCS service] conneclor IApprox. 3 V
26BLKGND3(Gtound 3)Ground tor the ABS controluntI.26-GNDBelow 0.3 V
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ABS CONTROL UNIT 22P CONNECIOR
Wire side ol lemale terminals
TerminalnumDerWirecolorTerminal 3i9nTerminal nameDescription
Voltage
Conditions(lgnition Switch ON (ll)lOutput voltagetominals
1RED/BLUFR-IN(Front-right
inlet)
Drives right-front inletsolenoid valve.
1-GND.9otur
ONIONOV
OFFAC:3-6V
OFF
lconnect the SCS servicel
connedor lApprox.3 V
BRN(Service checksignal)
Detects service check signal(Diagnostic trouble codeindication)4.GND
SCS service connectorconnected.OV
SCS service connectordisconnected.Approx. S V
7BLU/RED(Warning
ramp)
Drives ABS indicator {The indi-
cator goes off when ABS con-
trol unit outputs battery volt-age).
7.GND
lndicator ONApprox. 2 V
lndicator OFFBattery Voltage
10YEUBLKFL-OUT(Frontieft
outlet)
Drives left-front outletsolenoid valve.1O-GNDON
=
I
ONOV
OFFAC:3-6V
l'lRED/BLKFL-IN(Front-left inlet)
Drives left-front inlet solenoid11-GNDOFF
lconnect the SCS servicq connector lApprox.3 V
YEUBLUFR-OUT(Front-right
outlet)
Drives right-front outletsolenoid valve.12-GND
14LT BLU(Data linkconnectod
Communicates with HondaPGM Tester.14-GNDApprox. 5 V
17BRN/YELMCK(Motor check)
Detects PumP motor drivesignal.17-GNDPumpmotorrelay
ONBattery Vollage
OFFOV
19YEUREDPMR(Pump motorreray,
Drives pump motor relay.
19.GNDcl)
ON6IONOV
OFFAC:3-6V
OFFponnecl the SCS service]
connector IApprox.3 V
BLURR-OUT(Rear-right
outlet)
Drives right-rear outletsolenoid valve.
21.GND'a)
ONPumpmororrcray
ONOV
OFFAC:3 6V
OFF
lconnect the SCS service] connector lApprox.3 V
BLKGND2(Ground 2)Ground for the ABS controlunit.22.GNDBelow 0.3 V
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Troubleshooting Precautions
ABS lndicalor
1 lf the system is oK, the ABS indicator goes off two seconds after turning the ignition switch oN 1l) wathout staningthe engine, and then comes on again and goes off after two seconds. This occurs because the ABS control unit isturned on by the lG2 power source.2. The ABS indicator comes on when the ABS control unit detects a problem in the system. However, even thouoh thesystem is operating properly, the ABs indicator will come on too, under the following conditions:. Signal disturbance
. Wheel spin
. Only drive wheels rotate. Battery voltage fluctuates
To determine the actual cause of the problem, question the customer about the problem, taking these conditions intoconsideration:
3 When a problem is detected and the ABS indicator comes on, the indicator can stay on until the ignition switch isturned OFF, or it can automatically go off, depending on the mode.. Indicator stays on untilthe ignition switch is turned off: When the system is in the system down mode.. Indicator automatically goes off: When the system is in the control inhibition mode.4 The ABS indicator stays on when the system is reactivated without erasing the DTC, but it goes off after starting thevehicle.
When the wheel sensor system is faulty and the ABS indicator comes on. the algorithm of the system automatically turnsoff the ABS indicator after the wheel speed signal returns to the normal speed. Also, when the DTc is erased, the cpu isreset and the ABS indicator goes off when the system checked out normal by the initial diagnosis.Therefore, test-drive the vehicle after servicing the wheel sensor system. and be sure that the ABS indicator does notcome on.
5 When the ABS control unit outputs battery voltage to the gauge assembly, the ABS indicator ooes off.
Diagnostic Trouble Code (DTCI
1. The diagnostic trouble code (DTc) is memorized when a problem is detected and the ABS indicator does not go off,or when the ABS indicator comes on.The DTc is not memorized when the ABS indicator 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 tater 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 they 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 procedures toerase the DTCS.
Self-diagnosis
1. Self-diagnosis can be classified into these four categories:' Initial diagnosis: Performed right after the eng ine starts and untir theABS indicator goes off.. 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 is ON.2. The system performs the fo|owing contrors when a probrem is detected by the serf-diagnosis:. ABS indicator ON. Memorv of DTC. Mode changetothe "system down mode,, or the ,,control inhibition mode,,.
MODEABS INDICATORMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTEM
DOWNONNo
operation
Drive
inhibitionOperation*rlgnition
switchoFF - ON l)Memory
CONTROL
INHIBITIONONNo
operal|on
Drive
inhibitionOperationAutomaticlMemory
*1: Except CPU failure
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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. The ABS control unit operates the solenoid valve when the brake pedal is released after the initial diagnosis You may
hear the solenoid valve operate at this time, but it is normal
Pumo Motol
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 motor operate at this
time, but it is normal.
Brake Fluid Replacement/Ail Bleeding
L Brake fluid replacement and air bleeding procedures are the same as for vehicles without ABS To ease bleeding, start
with the front wheels.
Troubleshooting
1. The troubleshooting flowchart procedures assume that the cause of the problem is still present and the ABS indicator
is still on. Following the flowchart when the ABS indicator does not come on can result in incorrect diagnosis.
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
acceleration, during the specified vehicle speed, etc. Therefore, the symptom canngt be checked unless the check
conditions match with the problem conditjons
3. When the ABS jndicator does not come on during the test-drive. but troubleshooting is performed based on the DTC,
check lor loose connectors, poor contact of the terminals, etc., before you start troubleshooting.
4. After troubleshooting, erase the DTC and test-drive the vehicle. Be sure the ABS indicator does not come on.
5. The connector illustratjons show the female terminals with a single outline and the male terminals with a double out-
l ne.
ABS Function Test
To simulate ABS operation and activate the solenoid valves and pump, use the Honda PGM Tester.
Connect the PGM Tester to the 16P Data Link Connector (DLC). When the System Select menu is displayed, select the ABS
Test Mode menu, and follow the tester's prompts.
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