Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1168

BRAKE CONTROL SYSTEM

5A–1

RODEO

BRAKES

CONTENTS

Brake Control System . . . . . . . . . . . . . . . . . .

5A

Anti-lock Brake System . . . . . . . . . . . . . . . . .

5B

Power-assisted Brake System. . . . . . . . . . . .

5C

Parking Brakes (4x4 Model)  . . . . . . . . . . . . .

5D1

Parking Brakes (4x2 Model)  . . . . . . . . . . . . .

5D2

CONTENTS

Brake Control System

Service Precaution.........................................

5A–2

General Description .......................................

5A–3

Functional Description ................................

5A–4

System Components ..................................

5A–10

Electronic Hydraulic Control Unit (EHCU) ..

5A–10

ABS Warning Light .....................................

5A–10

Wheel Speed Sensor..................................

5A–10

G-Sensor ....................................................

5A–10

Normal and Anti-lock Braking .....................

5A–10

Brake Pedal Travel .....................................

5A–11

Acronyms and Abbreviations ......................

5A–11

General Diagnosis .........................................

5A–11

General Information ....................................

5A–11

ABS Service Precautions ...........................

5A–11

Computer System Service Precautions ......

5A–11

General Service Precautions ......................

5A–12

Note on Intermittents ..................................

5A–12

Test Driving ABS Complaint Vehicles ........

5A–12

“ABS” Warning Light ...................................

5A–12

Normal Operation .......................................

5A–12

Tech 2 Scan Tool .......................................

5A–13

DATA LIST .................................................

5A–16

ACTUATOR TEST......................................

5A–17

Tech 2 Service Bleed .................................

5A–21

Basic Diagnostic Flow Chart.......................

5A–22

Basic Inspection Procedure ........................

5A–23

EHCU Connector Pin-out Checks..................

5A–24

Circuit Diagram ...........................................

5A–25

Connector List ............................................

5A–28

Part Location ..............................................

5A–30

Symptom Diagnosis.......................................

5A–31

Chart A-1 ABS Works Frequently But

Vehicle Does Not Decelerate .....................

5A–31

Chart TA-1 ABS Works Frequently But

Vehicle Does Not Decelerate
(Use TECH 2).............................................

5A–32

Chart A-2 Uneven Braking Occurs While

ABS Works .................................................

5A–32

Chart TA-2 Uneven Braking Occurs While

ABS Works (Use TECH 2) .........................

5A–32

Chart A-3, TA-3 The Wheels Are Locked ...

5A–33

Chart A-4 Brake Pedal Feed Is Abnormal ..

5A–33

Chart A-5, TA-5 Braking Sound

(From EHCU) Is Heard While Not Braking .

5A–34

Diagnostic Trouble Codes ..........................

5A–35

Diagnosis By “ABS”  Warning Light

Illumination Pattern ....................................

5A–37

Diagnostic Trouble Codes (DTCs) ..............

5A–38

Chart B-1 With the key in the ON position

(Before starting the engine).   Warning
light (W/L) is not activated. .........................

5A–40

Chart B-2 CPU Error (DTC 14 (Flash out) /

C0271, C0272, C0273, C0284 (Serial
communications)) .......................................

5A–40

Chart B-3 Low or High Ignition Voltage

(DTC 15 (Flash out) / C0277, 0278 (Serial
communications)) .......................................

5A–41

Chart B-4 Excessive Dump Time (DTC 17

(Flash out) / C0269 (Serial communications))

5A–41

Chart B-5 Excessive Isolation Time (DTC 18

(Flash out) / C0274 (Serial communications))

5A–41

Chart B-6 G-Sensor Output Failure (DTC 21

(Flash out) / C0276 (Serial communications))  5A–42

Chart B-7 Brake Switch Failure (DTC 22

(Flash out) / C0281 (Serial communications))

5A–42

Chart B-8 2WD Controller in 4WD Vehicle

Controller (DTC 13 (Flash out) /   C0285
(Serial communications)), 4WD State Input

Signal Failure (DTC 24 (Flash out) / C0282
(Serial communications))..........................

5A–43

Chart B-9 Pump Motor Failure (DTC 32

(Flash out) / C0267, C0268 (Serial

communications)) .....................................

5A–43

Chart B-10 EHCU Valve Relay Failure

(DTC 35 (Flash out) / C0265, C0266
(Serial communications)) ...........................

5A–44

Chart B-11 FL Isolation Solenoid Coil Failure

(DTC 41 (Flash out) / C0245, C0247 (Serial
communications)) .......................................

5A–44

Chart B-12 FL Dump Solenoid Coil Failure

(DTC 42 (Flash out) / C0246, C0248 (Serial
communications)) .......................................

5A–44

SECTION

5A–2

BRAKE CONTROL SYSTEM

Chart B-13 FR Isolation Solenoid Coil Failure

(DTC 43 (Flash out) / C0241, C0243 (Serial
communications)) ......................................

5A–45

Chart B-14 FR Dump Solenoid Coil Failure

(DTC 44(Flash out) / C0242, C0244 (Serial
communications)).......................................

5A–45

Chart B-15 Rear Isolation Solenoid Coil

Failure (DTC 45 (Flash out) / C0251, C0253
(Serial communications)) ...........................

5A–45

Chart B-16 Rear Dump Solenoid Coil Failure

(DTC 46 (Flash out) / C0252, C0254 (Serial
communications)).......................................

5A–46

Chart B-17 FL Speed Sensor Open or Shorted

(DTC 51 (Flash out) / C0225 (Serial
communications)).......................................

5A–46

Chart B-18 FR Speed Sensor Open or

Shorted (DTC 52 (Flash out) / C0221 (Serial
communications)).......................................

5A–47

Chart B-19 Rear Speed Sensor Open or

Shorted (DTC 53 (Flash out) / C0235 (Serial
communications)).......................................

5A–48

Chart B-20 FL Speed Sensor Missing Signal

(DTC 61 (Flash out) / C0226, C0227 (Serial

communications)) .......................................

5A–49

Chart B-21 FR Speed Sensor Missing Signal

(DTC 62 (Flash out) / C0222, C0223 (Serial
communications)) .......................................

5A–50

Chart B-22 Rear Speed Sensor Missing

Signal (DTC 63 (Flash out) / C0236, C0237
(Serial communications)) ...........................

5A–51

Chart B-23 Simultaneous Drop-out of Front

Speed Sensor Signal (DTC 64 (Flash out) /
C0229 (Serial communications)) ................

5A–52

Chart B-24 Wheel Speed Input Abnormality

(DTC 65 (Flash out) / C0238 (Serial
communications)) .......................................

5A–53

Unit Inspection Procedure ..........................

5A–54

Chart C-1-1 FL Sensor Output Inspection

Procedure...................................................

5A–54

Chart C-1-2 FR Sensor Output Inspection

Procedure...................................................

5A–55

Chart C-1-3 Rear Sensor Output Inspection

Procedure...................................................

5A–55

Chart TC-1 Sensor Output Inspection

Procedure...................................................

5A–56

Special Tools .................................................

5A–57

Service Precaution

WARNING:  THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE 

SRS

COMPONENT  AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE
SRS COMPONENTS OR THE  SRS WIRING, REFER
TO THE 

SRS SERVICE INFORMATION. FAILURE TO

FOLLOW WARNINGS COULD RESULT IN POSSIBLE
AIR  BAG DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION:  Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after  removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE  SPECIFIED, do not
use supplemental coatings (Paints, greases, or
other corrosion inhibitors) on threaded fasteners  or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force,  and may damage the fastener.
When you install fasteners, use the correct
tightening sequence and specifications.  Following
these instructions can help you avoid damage to
parts and systems.

BRAKE CONTROL SYSTEM

5A–3

General Description

The Anti-lock Brake System (ABS) works on all four
wheels. A combination of wheel speed  sensor and
Electronic Hydraulic Control Unit (EHCU) can determine
when a wheel is about to stop turning and adjust  brake
pressure to maintain best braking.
This system helps the driver maintain greater control of

the  vehicle under heavy braking conditions.

NOTE:  The Electronic Hydraulic Control Unit (EHCU)
comprises the Hydraulic Unit (H/U) and the coil
Integrated Module.

C05RW004

EndOFCallout

Legend

(1) Electronic Line
(2) Hydraulic Line
(3) Hydraulic Unit (H/U)

(4) Coil Integrated Module
(5) Front Wheel Speed Sensor
(6) Rear Wheel Speed Sensor
(7) Proportioning and Bypass (P&B) Valve

5A–4

BRAKE CONTROL SYSTEM

Functional Description

Hydraulic Unit (H/U)

Solenoid Valve

C05RW012

EndOFCallout

Legend

(1) Isolation Valve
(2) Dump valve