Page 777 of 1681
Gomponent Locations
,)
ABS CONTROL UNIT
UNDER.HOOD FUSE/RELAYRGHT-NEAR WHEELsEillioRaoxLEFT.REAR WHEEI-SENSOR
UNDER-H(X)D ABS
MODULATOR UNIT
FAIL-SAFE RELAY
RIGHT-FRONT WHEELSENSOR
LEFT-FROl{T WHEELSENSOR
UNDER.HOOD FUSE/RELAY BOX
ABS INDICATOR
UNDER.HOOD ABS FUSE/RELAY 8OX
ABS 81 {20 AI FUSEAAS MOTOR {40 Al FUS€
AAS PUMP MOTOR RELAY
GAUGE ASSEMBLY
!D
Dtrt]
HORN/STOP I2O A) FUSE
A8S UNIT {10 AI FUSERR DEF FI-Y I7.5 AI FUSE
19-25
Page 779 of 1681

IABS Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehiclespeed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on therate of deceleration.
The ABS control unit calculates the slip rate of each wheel, and it transmits the control signal to the modulator unitsolenoid valve when the slip rate is high.
The pressure reduction control has three-modes: pressure reduction, pressure retaining, and pressure intensifying.
Self-diagnosis Function
The CPUS in the ABS control unit check the circuit of the system.
The self-diagnosis can be classifield into two categories.. Initial diagnosis: Performed right after the engine starts and until the ABS indicator gose off.. Regular diagnosis: Performed right after the initial diagnosis until the ignition switch isturnedoff.
On-board Diagnosis Function
The ABS control unit is connected to the data link connector fi6p).The ABS system can be diagnosed with the Honda PGM Tester.
(cont'd)
19-27
Page 785 of 1681

Terminal
numbel
Wire
color
Terminalsign
lTerminal
name,
Description
Measurement
T€rminalConditions(lgnition switch ON {ll}}Vohage
BLKMHTGND4(Ground 4)
G round12-GNDBelow 0.3 V
14BRN(Service
check signal)
Detects service check con-
nector signal (DTC indica-
tion or DTC erasure)
I4-GNDSCS short
connector
ConnectedBelow 0.3 V
DisconnectedApprox. 5 V
16BRNfYELMCK(Motor check)
Detects pump motor drive
srg nal16-GNDPump motorONBattery voltage
OFFBelow 0.3 V
17LT BLU
RLW (+)
{Rear-left
wheel positive)
Detects left-rear wheel sen-
sor signal
17-18
q,
3
Turn wheel at
l turn/second
AC:
0.053 V or
above
oscilloscope:
0.15 Vp-p or
aoove
18GRY
RLW (_)
(Rear-left
wheel negative)
19GRNIVEL
RRW (+)
(Rearright
wheel positive)
Detects right-rear wheel
sensor srgnal
19-20
20BLU//EL
RRW (-)
(Rear-right
wheel negative)Stops0.25 - 1.15 V
21YEUGRNFSR
{Fail-safe relay)
Drives failsafe relay
(Fail-safe relay is turned
OFF to shut off the power
source to the solenoid and
pump motor relay when
problem occurs.)
21-GNDABS indicator
ONBelow 0.3 V
OFFApprox. 11V
LT BLU
DLC(Data link
connectorl
Communicates with Honda
PGM Tester22-GND
19-33
Page 786 of 1681

ABS Control Unit Terminal Arrangement
ABS CONTROL UNIT 12P CONNECTOR
Wire side of female terminals
Terminal
number
Wire
colot
Terminal sign
(Tsrminal
name,
Doscription
Measuromgnt
TerminalConditions
{lgnhion switch ON {ll)}Voltage
BLU/RED(Warning
ramp,
Drives ABS indicator
1.GNDABS indicatorON3-6V
OFFBelow 0.3 V
,BLKGNDl
{Ground 1)
Ground2-GNDBelow 0.3 V
BLI(ORN
RR-OUT(Rear-right
outlet)
Drives right-rear outlet
solenoid valve3-GND
a
OFFBattery voltage
YEUBLU
FL.OUT(Front-left
outlet)
Drives left-front outlet
solenoid valve4-GND
YEL/WHT
RL-OUT(Rearleft
outlet)
Drives left-rear outlet
solenoid valve5.GND
ONBelow 0.3 V
YEUBLK
FR-OUT
(Front-right
outlet)
Drives right-front outlet
solenoid valve6-GND
7BLKGND2
(Ground 2)
G rou nd7-GNDBelow 0.3 V
8YEL
RR-IN(Rear-right
inlet)
Drives right-rear inlet
solenoid valve8.GND
.9
-@
OFFBattery voltage
IRED/B LU
FL-IN(Front-left
inlet)
Drives left-front inlet
solenoid valve9-GND
l0RED/WHT
RL-IN
{Rearleft
inlet)
Drives left-rear inlet
solenoid valve1O-GND
ONBelow 0.3 V
11RED/BLK
FR] N(Front-right
inlet)
Drives right-front inlet
solenoid valve11-GND
't2YEURED
PMR
{Pump motor
retay)
Drives pump motor relay
12-GND.9
.EU'@
OFFdE
ONBelow 1.0 V
OFFBattery voltage
ONBelow 0.3 V
19-34
Page 787 of 1681

Troubleshooting Precautions
ABS lndicator
1. lf the system is OK. the ABS indicator goes off two seconds after turning the ignition switch ON (ll) without starting
the engine, and then comes on again and goes off after two seconds. This occurs because the ABS control unit is
turned on bv the lG2 oower source.
2. The ABS indicator comes on when the ABS control unit detects a problem in the system. However, even though the
system is operating properly, the ABS indicator will come on under the following conditions.. Onlv drive wheels rotate
. One drive wheel is stuck
. Vehicle spin
. ABS continues to operate for a long time
. Signal disturbance
To determine the actual cause of problem. question the customer about the problem, taking these conditions into
consideration.
3. When a problem is detected and the ABS indicator comes on, there are cases when the indicator stays on until the
ignition switch is turned OFF, and cases when the indicator goes off automatically when the system returns to nor-
mal. For DTCS 61 and 62, the indicator goes off automatically when the system returns normal. For all other codes.
the indicator stays on until the ignition switch is turned OFF.
4. For DTCS 12, 14, 16, '18, 2'1,22, 23, 24,51,52 and 53, the indicator goes off when the vehicle is driven again and the
system is OK after the ignition switch is turned from OFF to ON (ll). However, if the DTC is erased, the CPU is reset
and the indicator goes off right after the engine is started if the system is OK.
Diagnostic Trouble Code (DTC)
1. lf the CPU cannot be actlvated and the indicator comes on, the DTC is not memorized.
2. The memory can hold any number of DTCS. However, when the same DTC is detected more than once, the later one
is written over the old one. Therefore, when the same problem is detected repeatedly, it is memorized 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 memory). Therefore, the memorized DTCS cannot be canceled
by disconnecting the battery. Perform the specified procedures to erase the DTCS,
S6lt-dirgnosis
1. Self-diagnosis can be classifield into two categories.
. Initial diagnosis: Performed right afterthe enginestansand untiltheABS indicator goes off.. Regular diagnosis: Performed rightafterthe initial diagnosis untilthe ignition switch isturned OFF.
2. When a problem is detected by self-diagnosis, the system
. Turns the fail-safe relay OFF
. Turns the solenoid valve OFF
. Turns the oumo motor OFF
. Turns the ABS indicator ON
Page 788 of 1681

Troubleshooting Precautions
Kickback
L 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.
Pump Motol
1. The pump motor operates when the ABS is functioning.
2. The ABS control unit checks the pump motor operation during initial diagnosis and when the vehicle is started. You
mav hear the motor operate at this time, but it is normal
Brake Fluid Replacement/Air Bleeding'1. Brake fluid replacement and air bleeding procedures are the same as vehicles without ABS. To ease bleeding, start
with the front wheels.
Troubleshooting
1. The troubleshooting flowcharts procedures assume that the cause of the problem is still present and the ABS indica-
tor 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.
Find out when the ABS indjcator came on. such as during initial diagnosis. during ABS control, after ABS control,
when vehicle speed was at a certain speed, etc.
3, When the ABS indicator does not come on during the test-drive, but troubleshooting is performed based on the DTC,
check for loose connectors, poor contact at 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 illustrations show the female terminals with a single outline and the male terminals with a double outline.
Page 789 of 1681

I
\
I
Diagnostic Trouble Code (DTC)
DTG lndication
a
t
NOTE: This operation can also be done with the Honda PGM Tester.
1. Connect the SCS short connector to the service check connector (2P) under the glove box,
2. Turn the ignition switch ON (ll) without the brake pedal depressed.
NOTE: lf the brake pedal is depressed when turning the ignition switch ON (ll), the system shifts to the DTC Erasure
mode.
3. The blinking frequency indicates the DTC.
NOTE: lf the DTC is not memorized, the ABS indicator will go off fo r 3.6 seconds, and then come back on.
4. Turn the ignition switch OFF, and remove the SCS short connector.
NOTE: The Malfunction Indicator Lamp (MlL) will stay on after the engine is started if the SCS shon connector is con-
nected.
Conditions lor DTC indication
. Vehicle speed is 6 mph (10 km/h) or less.
. The SCS short connector is connected before the ignition switch is turned ON {ll).
. The brake pedal is released.
ABS INOICATOB
SCS SHORT CONNECTORo?PAZ - 0010100
SERVICE CHECKCONNECTOR I2PI
DTC : 3 3
b
Page 790 of 1681

Diagnostic Trouble Code (DTC)
DTG Erasure (MES Mode)
NOTE: This operation can also be done with the Honda PGM Tester.
1. Connect the SCS short connector to the service check connector (2P) underthe glove box.
2, Deoress the brake pedal.
3. Turn the ignition switch ON (ll) while keeping the brake pedal depressed.
4. Afterthe ABS indicator goes off, release the brake pedal.
5. After the indicator comes on, depress the brake pedal again
6. After the indicator goes off, release the brake pedal again.
7. After a few seconds, the ABS indicator blinks twice and the DTC is erased. lf the indicator does not blink twice, repeat
steps 1 through 6. lf the indicator stays ON after the indicator blinks twice. check the DTC because a problem was
detected during initial diagnosis before shifting to DTC Erasure mode.
8. Turn the ignition switch OFF, and remove the SCS short connector.
Conditions lor DTC erasure
. Vehicle speed is 6 mph (10 km/h) or less.
. The SCS short connector is connected before the ignition switch is turned ON (ll).
. The brake pedal is depressed before the ignition switch isturned ON (ll)
ON
ABS INDICATOF
OFF
DEPRESSED
BRAKE PEDAL
RELEASED
Snilion switch
illr'I'
0.3soc.
'-------t
II2 sec,4 sgc.4 sec.5 aac.
0.3s6c.with in 3 s6c.with in 3 ssc.with in 3 s€c.
T
19-38