brake ISUZU TF SERIES 2004 Workshop Manual

5A-84 BRAKE CONTROL SYSTEM

DTC C0277 (Flash Code 77) Power Supply Low Input
DTC C0278 (Flash Code 78) Power Supply High Input



RTW45AMF000201

Step Action
Value(s) Yes No
1 Was the “Basic Diagnostic Flow Chart” performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Check for a poor connection at EHCU
2. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 3
3 1. Ignition “OFF”, disconnect EHCU.
2. Ignition “ON”, engine “OFF”.
3. Check the supply voltage to EHCU.
Was the value normal? Battery
Voltage Go to Step 5 Go to Step 4
4 Repair or replace the power supply circuit.
Was the action complete? - Verify repair -
5 1. Check the power supply circuit.
(Circuit for an open, short to ground, or short to
voltage.)
2. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 6

BRAKE CONTROL SYSTEM 5A-85

Step Action
Value(s) Yes No
6 1. Ignition “ON,” engine “OFF.”
2. Select “Display DTCs” with the Tech 2.
Note: Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 7 Verify repair
7 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-86 BRAKE CONTROL SYSTEM

DTC C0282 (Flash Code 82) 4 Wheel Drive State Input Signal Failure


RTW35AMF000301

Step Action
Value(s) Yes No
1 Was the “Basic Diagnostic Flow Chart” performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Check for a poor connection at EHCU and 2-4WD
control unit.
2. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 3
3 1. Ignition “OFF,” disconnect the EHCU and 2-4WD
control unit.
2. Check the circuit between EHCU and 2-4WD
control unit. (Circuit for an open, short to ground, or
short to voltage.)
3. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 4
4 1. Check the 2-4WD Control system.
2. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 5

BRAKE CONTROL SYSTEM 5A-87

Step Action
Value(s) Yes No
5 1. Ignition "OFF".
2. Connect 2-4WD control unit.
3. Disconnect EHCU.
4. Ignition "ON," engine "OFF."
5. Install the high impedance digital multimeter.
6. Check the transfer (2-4WD control unit) signal
value.
Was the value normal? Transfer 2WD
Mode: 8.3Hz
(
15%)
Transfer 4WD
Mode: 4.2Hz
(
15%) Go to Step 7 Go to Step 6
6 Replace 2-4WD control unit.
Was the action complete?
- Go to Step 7 -
7 1. Ignition “ON,” engine “OFF.”
2. Select “Display DTCs” with the Tech 2.
Note: Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 8 Verify repair
8 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-88 BRAKE CONTROL SYSTEM

DTC C0285 (Flash Code 85) Assembly error (G-sensor)


RTW35AMF000301

Step Action Value(s) Yes No
1 Was the “Basic Diagnostic Flow Chart” performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Ignition “OFF”.
2. Check for vehicle type and EHCU type.
(Vehicle type : 2WD or 4WD)
3. Checks the EHCU type is the same as a vehicles
type.
If the EHCU type differs from the vehicles type,
EHCU is replaced.
Note: Check the EHCU type for specification, when the
EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Go to Step 3 -
3 1. Check for vehicle type. (Vehicle type : 2WD or
4WD)
Was vehicle type 2WD? - Go to Step 4 Go to Step 6

BRAKE CONTROL SYSTEM 5A-89

Step Action Value(s) Yes No
4 1. Ignition "OFF".
2. Check for a poor condition at the EHCU harness
connector.
3. Check the EHCU circuit for an open, short to
ground, or short to voltage. Also, check the EHCU
ignition feed circuit for an open or short to ground
and the EHCU ground circuit for an open or short
to voltage.
4. If a problem is found, repair as necessary.
Was a problem found? - Verify repair Go to Step 9
5 1. Ignition "OFF," disconnect the EHCU and G-
sensor.
2. Check the circuit between EHCU and G-sensor.
(short to ground, or short to voltage.)
3. If a problem is found, repair as necessary.
Was a problem found? - Verify repair
Go to Step 6 Go to Step 6
6 1. Remove the G-sensor.
2. Reconnect G-sensor and EHCU
3. Install the Tech 2.
4. Ignition "ON", engine "OFF".
5. Observe the G-sensor reading on Tech 2.
If G-sensor inclines, reading voltage will change.
Is the reading voltage between specified value? 1.0 – 4.0 V Go to Step 7 Go to Step 8
7 1. Ignition "OFF".
2. Install the G-sensor.
3. Install the Tech 2.
4. Ignition "ON", engine "OFF".
5. Select "Display DTCs" with the Tech 2.
Are any DTCs stored? - Go to Step 8 Verify repair
8 1. Replace G-sensor.
2. Select "Display DTCs" with the Tech 2.
Note: Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 9 Verify repair
9 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-90 BRAKE CONTROL SYSTEM

Special Tools

ILLUSTRATION TOOL NO.
TOOL NAME
5–8840–0385–0
(J–35616)
Connector test adapter
kit
5–8840–0366–0
(J–39200)
High impedance
multimeter
Tech 2 Set
(1) PCMCIA Card
(2) SAE 16/19 Adapter
(3) DLC Cable
(4) Tech 2

ANTI-LOCK BRAKE SYSTEM 5B-1

SECTION 5B
BRAKES
ANTI-LOCK BRAKE SYSTEM
TABLE OF CONTENTS
PAGE
Service Precaution ...................................................................................................................... 5B – 2
Torque Specifications ................................................................................................................ 5B – 3
Electronic Hydraulic Control Unit ........................................................................................... 5B – 7
Electronic Hydraulic Control Unit and Associated Parts ............................................ 5B – 7
Removal .................................................................................................................................... 5B – 7
Installation ................................................................................................................................ 5B – 7
Front Wheel Speed Sensor ....................................................................................................... 5B – 8
Front Wheel Speed Sensor and Associated Parts ........................................................ 5B – 8
Removal .................................................................................................................................... 5B – 9
Inspection and Repair ........................................................................................................... 5B – 9
Installation ................................................................................................................................ 5B – 10
Rear Wheel Speed Sensor ........................................................................................................ 5B – 11
Rear Wheel Sensor and Associated Parts ....................................................................... 5B – 11
Removal .................................................................................................................................... 5B – 11
Inspection and Repair ........................................................................................................... 5B – 11
Installation ................................................................................................................................ 5B – 12
Front Speed Sensor Rotor ........................................................................................................ 5B – 13
Front Sensor Rotor and Associated Parts ....................................................................... 5B – 13
Removal .................................................................................................................................... 5B – 13
Inspection and Repair ........................................................................................................... 5B – 14
Installation ................................................................................................................................ 5B – 14
Rear Speed Sensor Rotor .......................................................................................................... 5B – 16
Rear Sensor Rotor and Associated Parts ........................................................................ 5B – 16
Removal .................................................................................................................................... 5B – 16
Inspection and Repair ........................................................................................................... 5B – 17
Installation ................................................................................................................................ 5B – 17
G-Sensor ........................................................................................................................................ 5B – 19
G-Sensor and Associated Parts ......................................................................................... 5B – 19

5B -2 ANTI-LOCK BRAKE SYSTEM

Removal .................................................................................................................................... 5B – 19
Installation ................................................................................................................................ 5B – 19
Special Tools ........................................................................................................................... 5B – 20


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.

ANTI-LOCK BRAKE SYSTEM 5B-3

Torque Specifications
Electronic Hydraulic Control Unit

This illustration is based
on RHD model
E05R300007