relay ISUZU AXIOM 2002 Service User Guide

1A±116
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
ConditionPossible causeCorrection
Magnetic clutch does not workÐRefer to Chart A
Chart A: Magnetic Clutch Does Not work
StepActionValue(s)Ye sNo
1Is the fuse No.F±7 normal?
ÐGo to Step 2
Replace the
fuse
2Is the relay No.X±2 (compressor relay) No.X±8 (A/C
thermo relay) and No.X±1 (heater relay) normal?
ÐGo to Step 3
Replace the
relay
3Is there continuity between the pressure switch side
connector terminal No.C21±1 and No.C21±2?
ÐGo to Step 5Go to Step 4
4Pressure switch defective or refrigerant pressure
improper.
Pressure switch replaced or refrigerant pressure
adjusted?
ÐGo to Step 3Ð
51. Turn the ignition switch on. (the engine is run.)
2. Turn the air conditioner switch on.
Is the battery voltage applied between the harness side
connector terminal No.E2±1 and the ground?
ÐGo to Step 7Go to Step 6
6Magnetic clutch defective or earth defective.
Magnetic clutch replaced or earth replaced?
ÐGo to Step 5Ð
7Is there continuity between the harness side connector
terminal No.X2±1 and No.E2±1?
ÐGo to Step 9Go to Step 8
8Repair an open circuit between terminal No.X2±1 and
No.E2±1.
Is the action complete?
ÐGo to Step 7Ð
9Is the battery voltage applied between the harness side
connector terminal No.X2±5 and ground, No.X2±2 and
ground?
ÐGo to Step 11Go to Step 10
10Repair an open circuit between terminal No.X2±5 and
fuse No.F±7, No.X2±2 and fuse No.F±7.
Is the action complete?
ÐGo to Step 9Ð
11Is the battery voltage applied between the harness side
connector terminal No.I20±18 and ground?
ÐGo to Step 13Go to Step 12
12Repair an open circuit between terminal No.I20±18 and
No.X2±4.
Is the action complete?
ÐGo to Step 11Ð
13Is the battery voltage applied between the harness side
connector terminal No.C21±2 and ground?
ÐGo to Step 15Go to Step 14
14Repair an open circuit between terminal No.C21±2 and
fuse No.F±7.
Is the action complete?
ÐGo to Step 13Ð
15Is the battery voltage applied between the harness side
connector terminal No.X8±5 and ground, No.X8±2 and
ground?
ÐGo to Step 17Go to Step 16
16Repair an open circuit between terminal No.X8±5 and
No.C21±1, No.X8±2 and fuse No.F±7.
Is the action complete?
ÐGo to Step 15Ð

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±119
Power Transistor
1. Remove the power transistor connector (C±34) from
the evaporator assembly.
2. Check the conduction between the power transistor
side terminals.
C01R200006
MAX HI Relay
1. Remove the MAX ± HI relay connector (C±35) from
the blower assembly.
2. Check the conduction between the MAX ± HI relay
side terminals.
C01R200011
In Car Sensor
1. Turn on the ignition switch (the engine is started).
Start the air conditioner in ªAutoº.
2. Make sure that the in car sensor suctions cigarette
smokes and such.
In Car Sensor
1. Dismount the in car sensor from the automatic
heater/air conditioner control unit. Connect (+) end
and (±) end of the battery to the aspirator motor side
terminals No.I17±1 and No.I17±2, respectively, then
check if the motor runs normally.
C01R200010

1A±120
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Heater (X±1) And Compressor (X±2) Relay
1. Disconnect relays and check for continuity and
resistance between relay terminals.

For handling of these relays, refer to
Heater Relay
in this section.
C01R200011
Thermostat (X±8) Relay
1. Disconnect relays and check for continuity and
resistance between relay terminals.

For handling of these relays, refer to
Heater Relay
in this section.
C01R200012
Triple Pressure Switch
1. Disconnect the connector and check for continuity
between pressure switch side connector terminals (1)
and (2).
2. Reconnect the connector to activate the A/C switch,
and check to see if there is continuity between the
chassis side connector terminal (3) and (4) and the
fan operates.
875R200020

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±121
On-Vehicle Service
Power Transistor
874R200014
Legend
(1) Glove Box
(2) MAX HI Relay
(3) Power Transistor Connector
(4) Power Transistor
Removal
1. Remove the glove box.
2. Remove the MAX±HI relay.
3. Disconnect the power transistor connector.
4. Remove the power transistor.
Installation
To install, follow the removal step in the reverse order.
Automatic Heater/Air Conditioner
Control Unit
865R200007
Legend
(1) Display
(2) Audio & Switch Assembly
(3) Automatic Air Conditioner Control Unit
(4) Knee Pad (RH)
(5) Center Cluster
(6) Center Cluster Upper
(7) Knee Pad (LH)
Removal
1. Disconnect the battery ground cable.
2. Remove the knee pad (R/LH).
3. Remove the center cluster upper.
4. Remove the center cluster.

Refer to
Instrument Panel Assembly in Body
Stractur section.
5. Disconnnect the six connectors.
6. Remove the automatic air conditioner control unit.
Installation
To install, follow the removal step in the reverse order.

5A±1
BRAKE CONTROL SYSTEM
AXIOM
BRAKES
CONTENTS
Brake Control System 5A±1. . . . . . . . . . . . . . . . . . . .
Anti±lock Brake System 5B±1. . . . . . . . . . . . . . . . . .
Power±assisted Brake System 5C±1. . . . . . . . . . . .
Parking Brakes (4x4 Model) 5D1±1. . . . . . . . . . . . . .
Parking Brakes (4x2 Model) 5D2±1. . . . . . . . . . . . . .
Brake Control System
CONTENTS
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±10. . . . . . . . . . . . . . . . . . . .
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±11. . . . . . . . . . . .
Note on Intermittents 5A±11. . . . . . . . . . . . . . . . . . .
Test Driving ABS Complaint Vehicles 5A±12. . . . .
ªABSº 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±29. . . . . . . . . . . . . . . . . . . . . . . . .
Symptom Diagnosis 5A±30. . . . . . . . . . . . . . . . . . . . .
Chart A-1 ABS Works Frequently But
Vehicle Does Not Decelerate 5A±30. . . . . . . . . . .
Chart TA-1 ABS Works Frequently But
Vehicle Does Not Decelerate
(Use TECH 2) 5A±31. . . . . . . . . . . . . . . . . . . . . . . .
Chart A-2 Uneven Braking Occurs While
ABS Works 5A±31. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart TA-2 Uneven Braking Occurs While
ABS Works (Use TECH 2) 5A±31. . . . . . . . . . . . . Chart A-3, TA-3 The Wheels Are Locked 5A±32.
Chart A-4 Brake Pedal Feed Is Abnormal 5A±32.
Chart A-5, TA-5 Braking Sound
(From EHCU) Is Heard While Not Braking 5A±33
Diagnostic Trouble Codes 5A±34. . . . . . . . . . . . . . . .
Diagnosis By ªABSº Warning Light
Illumination Pattern 5A±36. . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (DTCs) 5A±37. . . . . . .
Chart B-1 With the key in the ON position
(Before starting the engine). Warning light
(W/L) is not activated. 5A±39. . . . . . . . . . . . . . . . .
Chart B-2 CPU Error (DTC 14 (Flash out) /
C0271, C0272, C0273, C0284 (Serial
communications)) 5A±39. . . . . . . . . . . . . . . . . . . . .
Chart B-3 Low or High Ignition Voltage
(DTC 15 (Flash out) / C0277, 0278 (Serial
communications)) 5A±40. . . . . . . . . . . . . . . . . . . . .
Chart B-4 Excessive Dump Time (DTC 17
(Flash out) / C0269 (Serial
communications)) 5A±40. . . . . . . . . . . . . . . . . . . . .
Chart B-5 Excessive Isolation Time
(DTC 18 (Flash out) / C0274
(Serial communications)) 5A±40. . . . . . . . . . . . . . .
Chart B-6 G-Sensor Output Failure
(DTC 21 (Flash out) / C0276
(Serial communications)) 5A±41. . . . . . . . . . . . . . .
Chart B-7 Brake Switch Failure
(DTC 22 (Flash out) / C0281
(Serial communications)) 5A±41. . . . . . . . . . . . . . .
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±42. . . . . . . . . . . . . . .
Chart B-9 Pump Motor Failure
(DTC 32 (Flash out) / C0267, C0268
(Serial communications)) 5A±42. . . . . . . . . . . . . . .
Chart B-10 EHCU Valve Relay Failure
(DTC 35 (Flash out) / C0265, C0266
(Serial communications)) 5A±43. . . . . . . . . . . . . . .
Chart B-11 FL Isolation Solenoid Coil Failure
(DTC 41 (Flash out) / C0245, C0247
(Serial communications)) 5A±43. . . . . . . . . . . . . . .
Chart B-12 FL Dump Solenoid Coil Failure
(DTC 42 (Flash out) / C0246, C0248
(Serial communications)) 5A±43. . . . . . . . . . . . . . .

5A±16BRAKE CONTROL SYSTEM
DATA LIST
The data displayed by DATA LIST are as follows:
Display
ContentOK/NG Criteria for Data
Front Left Wheel Speed
Front Right Wheel Speed
Rear Wheel Speedskm/h (MPH)
Start the vehicle and make sure of linear change in
each wheel speed.

Turn each wheel by hand and make sure that each
speed data change.
Warning LampON/OFF
To be OFF usually
ABS StateON/OFF
To be OFF usually
ABS RelayActive/Inactive
To be Active usually
4 Wheel DriveActive/Inactive
2WD: Inactive

4WD: Active
Brake SwitchActive/Inactive
Inactive (Released)

Active (Pressed)
Brake Fluid LevelNormal or not
To be Normal usually
Return PumpActive/Inactive
To be Inactive usually
DRP (Dynamic Rear
Proportioning)Active/Inactive
To be Inactive usually
Rear Dump Valve CommandedActive/Inactive
To be Inactive usually
Rear Dump Valve Feedback
Rear Isolation Valve
Commanded
Rear Isolation Valve Feedback
FL Dump Valve CommandedActive/Inactive
To be Inactive usually
FL Dump Valve Feedback
FL Isolation Valve Commanded
FL Isolation Valve Feedback
FR Dump Valve CommandedActive/Inactive
To be Inactive usually
FR Dump Valve Feedback
FR Isolation Valve
Commanded
FR Isolation Valve Feedback
G±SensorVoltage
2.50V when vehicle is stopped
Battery VoltageVoltage
Between 10±16.9V

5A±29
BRAKE CONTROL SYSTEM
Part Location
810R200002
Legend
(1) Battery
(2) Fuse & Relay Box
(3) C±16
(4) C±5
(5) C±6
(6) H±8, 14
(7) I±18
(8) Starter Switch(9) I±24
(10) C±39
(11) F±4
(15) C±10
(16) C±28
(17) H±5
(19) E±23
(21) C±1

5A±34BRAKE CONTROL SYSTEM
Diagnostic Trouble Codes
Choose and trace an appropriate flowchart by the
numbers listed below to find fault and repair.
Code
ChartFlash outSerial
CommunicationsDiagnosisItemChart
No.
12ÐÐÐÐ
13C02852 WD Controller in 4WD Vehicle ControllerWiringB-8
14C0271RAM read/write error
C0272ROM checksum errorCoil
C0270ALU function error
Coil
Integrated
Mdl
B-2
C0273Inoperative isolation itemModule
C0284Loop time overrun
15C0277Low ignition voltageWiringB-3C0278High ignition voltageWiringB-3
17C0269Excessive dump timeB-4
18C0274Excessive isolation timeCoil
IntegratedB-5
21C0276G-Sensor FailureIntegrated
ModuleB-6
22C0281Brake switch FailureB-7
24C0282Open or shorted 4y4 input signal (4WD only)WiringB-8
32C0267Open motor circuit or shorted ECU outputMotorB-9C0268Stalled motor or open ECU outputMotorB-9
35C0265Open relay circuitRelayB-10C0266Shorted relay circuitRelayB-10
41C0245FL Open isolation solenoid or shorted ECU outputB-11C0247FL Shorted isolation solenoid or open ECU outputB-11
42C0246FL Open dump solenoid or shorted ECU outputB-12C0248FL Shorted dump solenoid or open ECU outputB-12
43C0241FR Open isolation solenoid or shorted ECU outputB-13C0243FR Shorted isolation solenoid or open ECU outputSolenoid
B-13
44C0242FR Open dump solenoid or shorted ECU outputSolenoid
B-14C0244FR Shorted dump solenoid or open ECU outputB-14
45C0251Rear Open isolation solenoid or shorted ECU outputB-15C0253Rear Shorted isolation solenoid or open ECU outputB-15
46C0252Rear Open dump solenoid or shorted ECU outputB-16C0254Rear Shorted dump solenoid or open ECU outputB-16

5A±43
BRAKE CONTROL SYSTEM
Chart B-10 EHCU Valve Relay Failure (DTC 35 (Flash out) / C0265, C0266 (Serial
communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Measure the voltage between terminal 1 of the coil integrated
module connector (C-5) and body ground.
Is the voltage equal to the battery voltage?
Replace EHCU.
Go to
Step 2
Repair fuse and
harness between
coil integrated
module connector
(C-5) terminal 1
and battery.
Go to
Step 2
21. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 2
Chart B-11 FL Isolation Solenoid Coil Failure (DTC 41 (Flash out) / C0245, C0247 (Serial
communications))
StepActionYe sNo
1Was the ªEHCU Connector Pin±out Checksº performed?
Go to Step 2
Go to ªEHCU
Connector
Pin±out Checks.º
21. Turn the key switch to off.
2. Disconnect the 2±way EHCU connector (C±5) from the
EHCU.
3. Inspect the connector for damage or corrosion.
Is the connector free from damage or corrosion?
Go to Step 3
Repair the
connector.
Repeat the ªBasic
Diagnostic Flow
Chart.º
31. Replace the Coil Integrated Module.
2. Reconnect all components, ensure all components are
properly mounted.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 3
Chart B-12 FL Dump Solenoid Coil Failure (DTC 42 (Flash out) / C0246, C0248 (Serial
communications))
StepActionYe sNo
1Was the ªEHCU Connector Pin±out Checksº performed?
Go to Step 2
Go to ªEHCU
Connector
Pin±out Checks.º
21. Turn the key switch to off.
2. Disconnect the 2±way EHCU connector (C±5) from the
EHCU.
3. Inspect the connector for damage or corrosion.
Is the connector free from damage or corrosion?
Go to Step 3
Repair the
connector.
Repeat the ªBasic
Diagnostic Flow
Chart.º
31. Replace the Coil Integrated Module.
2. Reconnect all components, ensure all components are
properly mounted.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 3

5C±10
POWER±ASSISTED BRAKE SYSTEM
Hydraulic Brakes
Filling Master Cylinder Reservoir
CAUTION: Use only specified brake fluid. Do not
use any fluid which contains a petroleum base. Do
not use a container which has been used for
petroleum based fluids or a container which is wet
with water. Petroleum based fluid will cause swelling
and distortion of rubber parts in the hydraulic brake
system. Water mixed with brake fluid lowers the fluid
boiling point. Keep all fluid containers capped to
prevent contamination.
Always fill the master cylinder reservoir when the en-
gine is cold.
Never allow the brake fluid to come in contact with
the painted surfaces.
The master cylinder reservoir must be kept properly
filled to ensure adequate reserve and to prevent air
and moisture from entering the hydraulic system.
However, because of expansion due to heat ab-
sorbed from the brakes and the engine, the reservoir
must not be overfilled. The brake fluid reservoir is on
the master cylinder, which is located under the hood
on the left side of the cowl. Thoroughly clean reser-
voir cap before removal to avoid getting dirt into res-
ervoir. Remove the diaphragm. Add fluid as required
to bring level to the ªMAXº mark on the reservoir
tank. Use ªDOT 3º Hydraulic Brake Fluid. If the fluid
cap diaphragm is stretched, return it to the original
position before installing.
Deterioration of Brake Fluid
Using any other brake fluid than specified or brake fluid
with mineral oil or water mixed in will drop the boiling point
of brake fluid. It may, in turn, result in vapor lock or
deteriorated rubber parts of the hydraulic system. Be sure
to change the brake fluid at specified intervals.
If the rubber parts are deteriorated, remove all the system
parts and clean them with alcohol. Prior to reassembly,
dry the cleaned parts with air to remove the alcohol.
Replace all the hoses and rubber parts of the system.
Leakage of Brake Fluid
With engine idling, set shift lever in the neutral position
and continue to depress brake pedal at a constant pedal
application force.
Should the pedal stroke become deeper gradually,
leakage from the hydraulic pressure system is possible.
Perform visual inspection for any signs of leakage.
Bleeding Brake Hydraulic System
A bleeding operation is necessary to remove air from the
hydraulic brake system whenever air is introduced into
the hydraulic system. It may be necessary to bleed the
hydraulic system at all four brakes if air has been
introduced through a low fluid level or by disconnecting
brake pipes at the master cylinder. If a brake pipe is
disconnected at one wheel, only that wheel
cylinder/caliper needs to be bled. If the pipes aredisconnected at any fitting located between the master
cylinder and brakes, then the brake system served by the
disconnected pipe must be bled.
1. For 4±Wheel Antilock Brake System (ABS) equipped
vehicle, be sure to remove the ABS main fuse 60A
located at the relay and fuse box before bleeding air. If
you attempt to bleed air without removing the main
fuse, air cannot be let out thoroughly, and this may
cause damage to the hydraulic unit. After bleeding air,
be sure to replace the ABS main fuse back to its
original position.
2. Set the parking brake completely, then start the
engine.
NOTE: The vacuum booster will be damaged if the
bleeding operation is performed with the engine off.
3. Remove the master cylinder reservoir cap.
4. Fill the master cylinder reservoir with brake fluid.
Keep the reservoir at least half full during the air
bleeding operation
5. Always use new brake fluid for replenishment.
6. When replenishing the brake fluid reservoir, carefully
pour in the brake fluid to prevent air bubbles from
entering the brake system.
When the master cylinder is replaced or overhauled,
first bleed the air from the master cylinder, then from
each wheel cylinder and caliper following the
procedures described below.
Bleeding the Master Cylinder
7. Disconnect the rear wheel brake pipe (1) from the
master cylinder.
Check the fluid level and replenish as necessary. If
replenished, leave the system for at least one minute.
8. Depress the brake pedal slowly once and hold it
depressed.
9. Completely seal the delivery port of the master
cylinder with your finger, where the pipe was
disconnected then release the brake pedal slowly.
10. Release your finger from the delivery port when the
brake pedal returns completely.
11. Repeat steps 8 through 10 until the brake fluid comes
out of the delivery port during step 8.
NOTE: Do not allow the fluid level in the reservoir to go
below the half±way mark.
12. Reconnect the brake pipe (1) to the master cylinder
and tighten the pipe.
13. Depress the brake pedal slowly once and hold it
depressed.
14. Loosen the rear wheel brake pipe (1) at the master
cylinder.
15. Retighten the brake pipe, then release the brake
pedal slowly.
16. Repeat steps 13 through 15 until no air comes out of
the port when the brake pipe is loosened
NOTE: Be very careful not to allow the brake fluid to come
in contact with painted surfaces.