Brakes; Brake Control System - Isuzu Trooper 1999 Workshop Manual

TROOPER

Brake Control System

. . . . . . . . . . . . . . . . . . . .
Anti–lock Brake System . . . . . . . . . . . . . . . . . .
Service Precaution . . . . . . . . . . . . . . . . . . . . . .
General Description . . . . . . . . . . . . . . . . . . . . .
System Components . . . . . . . . . . . . . . . . . . .
Electronic Hydraulic Control Unit (EHCU)
ABS Warning Light . . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor . . . . . . . . . . . . . . . . . .
G-Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal and Anti-lock Braking
Brake Pedal Travel . . . . . . . . . . . . . . . . . . . .
Acronyms and Abbreviations
General Diagnosis . . . . . . . . . . . . . . . . . . . . . . .
General Information . . . . . . . . . . . . . . . . . . . .
ABS Service Precautions
Computer System Service Precautions
General Service Precautions
Note on Intermittents . . . . . . . . . . . . . . . . . . .
Test Driving ABS Complaint Vehicles
"ABS" Warning Light . . . . . . . . . . . . . . . . . . .
Normal Operation . . . . . . . . . . . . . . . . . . . . .
Basic Diagnostic Flow Chart
Basic Inspection Procedure
Tech 2 Scan Tool . . . . . . . . . . . . . . . . . . . . . .
Getting Started . . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure . . . . . . . . . . . . . . . . . . .
Data List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EHCU Connector Pin-out Checks
Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . .
Connector List . . . . . . . . . . . . . . . . . . . . . . . .
Part Location . . . . . . . . . . . . . . . . . . . . . . . . .
Symptom Diagnosis . . . . . . . . . . . . . . . . . . . . .
Chart A–1 ABS Works Frequently But
Vehicle Does Not Decelerate
Chart TA-1 ABS Works Frequently But
Vehicle Does Not Decelerate
(Use TECH 2) . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-2 Uneven Braking Occurs While
ABS Works . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-3, TA-3 The Wheels Are Locked
Chart A-4 Brake Pedal Feed Is Abnormal
Chart A-5,TA-5 Braking Sound
(From EHCU) Is Heard While Not Braking
Diagnostic Trouble Codes
Diagnosis By "ABS" Warning Light
Illumination Pattern . . . . . . . . . . . . . . . . . . . . .

BRAKES

CONTENTS
5A–1
5B–1
BRAKE CONTROL SYSTEM
CONTENTS
5A–2
5A–3
5A–3
. 5A–3
5A–4
5A–4
5A–4
. . . . . . . . . . . 5A–4
5A–4
. . . . . . . . . . . . 5A–4
5A–5
5A–5
. . . . . . . . . . . . . . . 5A–5
. . . 5A–5
. . . . . . . . . . . . 5A–5
5A–5
. . . . . 5A–5
5A–6
5A–6
. . . . . . . . . . . . 5A–6
. . . . . . . . . . . . . 5A–7
5A–8
5A–9
5A–9
5A–11
. . . . . . . . . 5A–12
5A–13
5A–16
5A–18
5A–19
. . . . . . . . . . . 5A–19
5A–20
5A–20
. 5A–21
. 5A–21
5A–22
. . . . . . . . . . . . . . . . 5A–23
5A–24
BRAKE CONTROL SYSTEM
Power-Assisted Brake System
Parking Brakes . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (DTCs)
Chart B-1 With the key in the ON position
(Before starting the engine). Warning light
(W/L) is not activated.
Chart B-2 EHCU Abnormality (DTC 14)
Chart B-3 Power Voltage Drop (DTC 15)
Chart B-4 CLASS-2 Communication Line
Abnormality (DTC 16)
Chart B-5 G-Sensor Circuit (DTC 21)
Chart B-6 Abnormal Transmission Input
(DTC 23) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-7 Transfer Monitor (DTC 24)
Chart B-8 EHCU Pump Motor And Motor
Relay Circuit (DTC 32)
Chart B-9 EHCU Pump Valve And Valve
Relay Circuit (DTC 35)
Chart B-10 FL Isolation Solenoid Valve
Abnormality (DTC 41)
Chart B-11 FL Dump Solenoid Valve
Abnormality (DTC 42)
Chart B-12 FR Isolation Solenoid Valve
Abnormality (DTC 43)
Chart B-13 FR Dump Solenoid Valve
Abnormality (DTC 44)
Chart B-14 Rear Isolation Solenoid Valve
Abnormality (DTC 45)
Chart B-15 Rear Dump Solenoid Valve
Abnormality (DTC 46)
Chart B-16 FL Speed Sensor Disconnection
(DTC 51) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-17 FR Speed Sensor Disconnection
(DTC 52) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-18 RL Speed Sensor Disconnection
(DTC 53) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-19 RR Speed Sensor Disconnection
(DTC 54) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-20 FL Speed Sensor Short Circuit
(DTC 61) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-21 FR Speed Sensor Short Circuit
(DTC 62) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-22 RL Speed Sensor Short Circuit
(DTC 63) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-23 RR Speed Sensor Short Circuit
(DTC 64) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-24 Sensor Signal Input Abnormality
(DTC 65) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Signal Abnormality Criteria using
TECH 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Inspection Procedure
SECTION
5A–1
. . . . . . . . . . . . 5C–1
5D–1
. . . . . . . 5A–24
. . . . . . . . . . . . . . . . . 5A–27
. . . 5A–27
. . 5A–28
. . . . . . . . . . . . . . . . . 5A–28
. . . . . 5A–28
5A–29
. . . . . 5A–30
. . . . . . . . . . . . . . . . . 5A–30
. . . . . . . . . . . . . . . . . 5A–31
. . . . . . . . . . . . . . . . . 5A–31
. . . . . . . . . . . . . . . . . 5A–31
. . . . . . . . . . . . . . . . . 5A–32
. . . . . . . . . . . . . . . . . 5A–32
. . . . . . . . . . . . . . . . . 5A–32
. . . . . . . . . . . . . . . . . 5A–33
5A–33
5A–34
5A–34
5A–35
5A–36
5A–37
5A–38
5A–39
5A–40
5A–40
. . . . . . . . . . . . . . . . 5A–41