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
19-30
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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.
19-37
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lntegrated Control Unit
Input Test -'97 Model (cont'd)
At----------+A7
Key-in/Seat Belt Reminder, Lights-on Remindor System:
Cavity WireTest conditionTest: Desired rosultPossible cause if re3ult is nol obtainod
Bulb Check System (Brake System Light):
Cavity WireTest conditionT6st: DGsirgd rosultPossible cause if resuh is not obtainod
23-70
A8
Combination light
switch ON
Check for voltage to ground:
There should be battery voltage.
Blown No.30 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty combination light switch
An open in the wire
B7R ED/BLU
lgnition switch ON {lll.
and driver's seat belt
switch unbuckled
Check for voltage to ground:
There should be 1 V or less.
Poor ground (G552)
Faulty seat belt switch
Blown seat belt reminder light
bulb
An open in the wirelgnition switch ON (ll),
and driver's seat belt
switch buckled
Check for voltage to groundl
There should be 4 V or more.
B9GRN
Driver's door openCheck ior voltage to ground:
There should be 1 V or less.
. Faulty driver's door switch. An open in the wire
Driver's door closedCheck for voltage to ground:
There should be 4 V or more.
810BLU/RED
lgnition key insened
into the ignition key
switch
Check for voltage to ground;
There should be 1 V or less.
Poor ground (G401, G,[02)
Faulty ignition key switch
An open in the wire
lgnition key removed
trom the ignition key
swrtch
Check for voltage to ground:
There should be 4 V or more.
A4
lgnition switch ON { ll),
brake fluid reservoir
full, and parking brake
tever oown
Connect to ground: Brake system
light should come on.
Blown No. 25 (7.5 A) iuse in the
under-dash fuse/relay box
Blown brake system light bulb
An open in the wire
A13
lgnition switch at
START (lll), and
A/T gear position
switch E or E
Check for voltage to ground:
There should be battery voltage.
Blown No.31 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty starter cut relay
Faulty A/f gear position switch
Poor ground (G101)
An open in the wire
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Integrated Control Unit
A1 --------> A7
Input Test -'98 - 00 Models (cont'dl
YEL/BLULT GRNWHT/BLK
GRN/BLKLT GRN/REO
Wire side offemale terminals
A8------->A14WHT/BLK
Key-in/Se8t Beft Reminder, Lights-on Remindol System:
BLU/RED
Cavity WireTest conditionTest: Desired resultPossible caus€ it result is not obtained
Bulb Check System lBrake System Lightl:
Cavity WireTest conditionTest: Desired resultPossible caus€ if result is not obtained
A4
lgnition switch ON (ll),
brake fluid reservoir
full, and parking brake
lever down
Connect to ground: Brake system
light should come on.
Blown No. 25 (7.5 A) fuse in the
under-dash fuse/relay box
Blown brake system light bulb
An open in the wire
A13
lgnition switch at
START ( lll), and
A,/T gear position
switch E or E
Check for voltage to ground:
There should be battery voltage.
Blown No. 31 {7.5 A) fuse in the
under-dash fuse/relay box
Faulty sta rter cut relay
Faulty A,/T gear position switch (A,/T)
Faulty clutch interlock switch (M/T)
Poor ground {G101: AfI. G401 and
G402: M/T)
An open in the wire
23-74
A8
Combination light
switch ON
Check for voltage to ground:
There should be battery voltage.
Blown No. 30 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty combination light switch
An open in the wire
RED/BLU
lgnition switch ON ( ll),
and driver's seat belt
switch unbuckled
Check for voltage to ground:
There should be 1 V or less.
Poor ground {G552)
Faulty seat belt switch
Blown seat belt reminder light
bu lb
An open in the wirelgnition switch ON (ll),
and driver's seat belt
switch buckled
Check for voltage to ground:
There should be 4 V or more.
814GRN
Driver's door openCheck for continuity to ground:
There should be continuity,
. Faulty driver's door switch. An open in the wire
Driver's door closedCheck for continuity to ground:
There should be no continuity.
B8BLU/RED
lgnition key inserted
into the ignition key
swrtch
Check for voltage to ground:
There should be 'l V or less.
Poor ground (G401, G402)
Faulty ignition key switch
An open in the wire
lgnition key removed
from the ignition key
switch
Check for voltage to ground:
There should be 4 V or more.
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Daytime Running Lights Control Unit Input Test (Canadal
1.Remove the driver's dashboard lower cover and the
knee bolstet (see section 20).
Disconnect the connectors from the daytime run-
ning lights control unit.
Inspect the connector and socket terminals to be
sure they are all making good contact.
lf the terminals are bent, loose or corroded, repair
them as necessary, and recheck the system.
lf the terminals look OK, make the tollowing
inout tests at the connector'
- lf anv test indicates a problem, find and correct
the cause, then recheck the system.
- lf all the input tests prove OK, the control unrt
IPCONNECTOR
must be faulty; replace it.
T€st condition
DAYTIME RUNNING LIGHTS
CONTBOL UNIT
Tost: Desired result
8P CONNECTOR
YEL/BLK
GRN/RED
Possible cause ii r$uh is not obtained
BLK/WHT
Cavity
RED/GRN
B1BLKUnder all conditionsCheck for continuity to ground:
There should be continuity.
. Poor ground (G401, G402)
. An open in the wire
A2BLK,4iVHT
Under all conditionsCheck tor voltage to ground:
There should be battery voltage.
Blown No. 20 (7.5 A) luse in the
under-dash fuse/relay box
An open in the wire
82YEUBLK
lgnition switch oN (ll)Check for voltage to ground:
There should be battery voltage.
Blown No. 18 (7.5 A) fuse in the
under-dash tuse/relay box
Faulty ignition switch
An open in the wire
A4RED
Combination light
switch in " =D " Posi-
uon
Check for voltage to ground:
There should be battery voltage.
Blown No.,tg (30 A) fuse in the
under-hood fuse/relay box
Faulty combination light switch
An open in the wire
A1WHT/RED
Combination light
switch OFF; connect a
jumper wire between
the 82 and 41 termi-
nals, then turn the igni-
tion switch ON (ll)
Headlights (high beam) should
come on, (and high beam
indicator should come on).
Poor ground (G201. G202, G401,
G402)
Blown headlight bulbs
Faulty daytime running lights
resrslor
An open in the wire
R'IGRN/RED
lgnition switch ON (ll),
brake fluid reservoir
full. and parking brake
lever down
Connect to ground: The brake
system light should come on.
Blown No. 25 (7.5 A) fuse in the
under-dash fuse/relaY box
Blown brake system light
An open in the wire
B68EDlGRNParking brake lever upCheck for continuity to ground:
There should be continuity
. Faulty parking brake switch
. An open in the wire
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