light ISUZU TROOPER 1998 Service Service Manual

4C±5 DRIVE SHAFT SYSTEM
7. Remove the parking brake cable mounting
bolts(Behind the back plate)(1).
311RS001
8. Remove the bearing holder mounting nuts.
9. Remove axle shaft assembly.
NOTE: Be sure not to damage the oil seal.
10. Remove snap ring.
11. Using a bearing remover 5±8840±2295±0 and press,
remove retainer together with the bearing holder.
420RW024
12. Remove bearing.
13. Remove bearing holder.
14. Remove back plate.15. Remove the wheel pins using a remover
5±8840±0079±0.
420RW023
Inspection and Repair
Make necessary correction or parts replacement if wear,
corrosion or any other abnormal conditions are found
through inspection.
Visual Check:
Check the following parts for wear, damage, noise or any
other abnormal conditions:
1. Axle shaft
2. Bearing
When checking the axle shaft, pay special attention to the
splined portions and replace the shaft if distortion or step
wear is noticeable. Correct slight step wear with a grinder.
420RS008

TRANSFER CASE (STANDARD TYPE)
4D1±7
A/T, WO/Shift On The Fly, WO/4WD Switch, model
A07RW055
The transfer case is used to provide a means of providing
power flow to the front axle. The transfer case also
provides a means of disconnecting the front axle,
providing better fuel economy and quieter operation when
the vehicle is driven on improved roads where four wheel
drive is not required. In addition, the transfer case
provides an additional gear reduction when placed in low
range, which is useful when difficult off±road conditions
are encountered.
A floor mounted shift lever is used to select the high±low
range. When four wheel drive switch has been turned on,
the four wheel drive indicator light is designed to come on
when the front axle has been engaged.

4D1±34
TRANSFER CASE (STANDARD TYPE)
2. If the measured value exceeds the specified limit, the
gear must be replaced.
Gear inside diameter
Standard : 48.000±48.013 mm (1.8898±1.8903 in)
Limit : 48.10 mm (1.894 in)
226RS040
Clutch Hub Spline Play
1. Set a dial indicator to the clutch hub to measured.
2. Move the clutch hub as far as possible to both the right
and the left.
Note the dial indicator reading.
3. If the measured value exceeds the specified limit, the
clutch hub must be replaced.
Clutch hub spline play
Standard : 0±0.1 mm (0±0.004 in)
Limit : 0.2 mm (0.008 in)
226RS042
Bearings
1. Inspect the condition of all the needles and ball
bearings. Wash bearings thoroughly in a cleaning
solvent. Apply compressed air to the bearings.
NOTE: Do not allow the bearings to spin. Turn them
slowly by hand. Spinning bearings may damage the
rollers.
2. Lubricate the bearings with a light oil and check them
for roughness by slowly turning the race by hand.
Ball Bearing Play
1. Use a dial indicator to measure the ball bearing play.
2. If the measured value exceeds the specified limit, the
ball bearing must be replaced.
Limit : 0.2 mm (0.008 in)
226RS043
Synchronizers
The synchronizer hubs and sliding sleeves are a selected
assembly and should be kept together as originally
assembled.
Clean synchronizer components with clean solvent and
air dry.
Inspect the components for the following:

Teeth for wear, scuffs, nicks, burrs or breaks.

Keys and springs for wear, cracks or distortion,
replace if these conditions are present.

If scuffed, nicked or burred conditions cannot be
corrected with a soft stone or crocus cloth, replace the
component.
Block Ring and Insert Clearance
1. Use a vernier caliper to measure the clearance
between the block ring and the insert.
2. If the measured value exceeds the specified limit, the
block ring and the insert must be replaced.
Block ring and insert clearance
Standard : 2.46±2.74 mm (0.097±0.108 in)

5A±1 BRAKE CONTROL SYSTEM
BRAKES
CONTENTS
Brake Control System 5A. . . . . . . . . . . . . . . . . . . .
Anti±lock Brake System 5B. . . . . . . . . . . . . . . . . . Power±Assisted Brake System 5C. . . . . . . . . . . .
Parking Brakes 5D. . . . . . . . . . . . . . . . . . . . . . . . .
BRAKE CONTROL SYSTEM
CONTENTS
Service Precaution 5A±2. . . . . . . . . . . . . . . . . . . . . .
General Description 5A±3. . . . . . . . . . . . . . . . . . . . .
System Components 5A±3. . . . . . . . . . . . . . . . . . .
Electronic Hydraulic Control Unit (EHCU) 5A±3.
ABS Warning Light 5A±4. . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor 5A±4. . . . . . . . . . . . . . . . . .
G-Sensor 5A±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal and Anti-lock Braking 5A±4. . . . . . . . . . .
Brake Pedal Travel 5A±4. . . . . . . . . . . . . . . . . . . .
Acronyms and Abbreviations 5A±4. . . . . . . . . . . .
General Diagnosis 5A±5. . . . . . . . . . . . . . . . . . . . . . .
General Information 5A±5. . . . . . . . . . . . . . . . . . . .
ABS Service Precautions 5A±5. . . . . . . . . . . . . . .
Computer System Service Precautions 5A±5. . .
General Service Precautions 5A±5. . . . . . . . . . . .
Note on Intermittents 5A±5. . . . . . . . . . . . . . . . . . .
Test Driving ABS Complaint Vehicles 5A±6. . . . .
ªABSº Warning Light 5A±6. . . . . . . . . . . . . . . . . . .
Normal Operation 5A±6. . . . . . . . . . . . . . . . . . . . .
Basic Diagnostic Flow Chart 5A±6. . . . . . . . . . . .
Basic Inspection Procedure 5A±7. . . . . . . . . . . . .
Tech 2 Scan Tool 5A±8. . . . . . . . . . . . . . . . . . . . . .
Getting Started 5A±9. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure 5A±10. . . . . . . . . . . . . . . . . . .
Data List 5A±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EHCU Connector Pin-out Checks 5A±12. . . . . . . .
Circuit Diagram (LHD model / 6VD1 and
4JG2) 5A±13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram (LHD model / 4JG2) 5A±14. . . . .
Circuit Diagram (LHD model / 4JG2) 5A±15. . . . .
Circuit Diagram (LHD model / 6VD1) 5A±16. . . . .
Circuit Diagram (LHD model / 6VD1) 5A±17. . . . .
Connector List (LHD model) 5A±18. . . . . . . . . . . .
Part Location (LHD model) 5A±20. . . . . . . . . . . . . .
Circuit Diagram (RHD model / 6VD1 and
4JG2) 5A±21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram (RHD model / 4JG2) 5A±22. . . . .
Circuit Diagram (RHD model / 4JG2) 5A±23. . . . .
Circuit Diagram (RHD model / 6VD1) 5A±24. . . . .
Circuit Diagram (RHD model / 6VD1) 5A±25. . . . .
Circuit Diagram (RHD model / 6VE1 and
4JX1) 5A±26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Diagram (RHD model / 4JX1) 5A±27. . . . .
Circuit Diagram (RHD model / 4JX1) 5A±28. . . . .
Circuit Diagram (RHD model / 6VE1) 5A±29. . . . .
Circuit Diagram (RHD model / 6VE1) 5A±30. . . . .
Connector List (RHD model) 5A±31. . . . . . . . . . . .
Part Location (RHD model) 5A±34. . . . . . . . . . . . .
Symptom Diagnosis 5A±35. . . . . . . . . . . . . . . . . . . . .
Chart A±1 ABS Works Frequently But
Vehicle Does Not Decelerate 5A±35. . . . . . . . . . .
Chart TA-1 ABS Works Frequently But
Vehicle Does Not Decelerate (Use
TECH 2) 5A±36. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-2 Uneven Braking Occurs While
ABS Works 5A±36. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-3, TA-3 The Wheels Are Locked 5A±36.
Chart A-4 Brake Pedal Feed Is Abnormal 5A±37.
Chart A-5, TA-5 Braking Sound (From
EHCU) Is Heard While Not Braking 5A±38. . . . . .
Diagnostic Trouble Codes 5A±39. . . . . . . . . . . . . . . .
Diagnosis By ªABSº Warning Light
Illumination Pattern 5A±40. . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (DTCs) 5A±40. . . . . . .
Chart B-1 With the key in the ON position
(Before starting the engine). Warning light
(W/L) is not activated. 5A±43. . . . . . . . . . . . . . . . .
Chart B-2 EHCU Abnormality (DTC 14) 5A±43. . .
Chart B-3 Power Voltage Drop (DTC 15) 5A±44. .
Chart B-4 CLASS-2 Communication Line
Abnormality (DTC 16) 5A±44. . . . . . . . . . . . . . . . .
Chart B-5 G-Sensor Circuit (DTC 21) 5A±45. . . . .
Chart B-6 Abnormal Transmission Input
(DTC 23) 5A±46. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-7 Transfer Monitor (DTC 24) 5A±47. . . . .
Chart B-8 EHCU Pump Motor And Motor
Relay Circuit (DTC 32) 5A±47. . . . . . . . . . . . . . . . .
Chart B-9 EHCU Pump Valve And Valve
Relay Circuit (DTC 35) 5A±47. . . . . . . . . . . . . . . . .
Chart B-10 FL Isolation Solenoid Valve
Abnormality (DTC 41) 5A±48. . . . . . . . . . . . . . . . .
Chart B-11 FL Dump Solenoid Valve
Abnormality (DTC 42) 5A±48. . . . . . . . . . . . . . . . .
Chart B-12 FR Isolation Solenoid Valve
Abnormality (DTC 43) 5A±48. . . . . . . . . . . . . . . . .
Chart B-13 FR Dump Solenoid Valve
Abnormality (DTC 44) 5A±49. . . . . . . . . . . . . . . . .
Chart B-14 Rear Isolation Solenoid Valve
Abnormality (DTC 45) 5A±49. . . . . . . . . . . . . . . . .
Chart B-15 Rear Dump Solenoid Valve
Abnormality (DTC 46) 5A±49. . . . . . . . . . . . . . . . .

5A±3 BRAKE CONTROL SYSTEM
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.
C05RW027
Legend
(1) With P&B Valve Model
(2) With LSPV Model
(3) Electronic Hydraulic Control Unit (EHCU)
(4) Front Wheel Speed Sensor
(5) Rear Wheel Speed Sensor(6) G-Sensor
(7) Proportioning and Bypass (P&B) Valve
(8) Load Sensing Proportioning Valve (LSPV)
(9) Electronic Line
(10) Hydraulic Line
System Components
Electronic Hydraulic Control Unit (EHCU), four Wheel
Speed Sensors, Warning Light, and G-sensor.
Electronic Hydraulic Control Unit (EHCU)
The EHCU consists of ABS control circuits, fault detector,
and a fail-safe. It drives the hydraulic unit according to the
signal from each sensor, cancelling ABS to return to

5A±4
BRAKE CONTROL SYSTEM
normal braking when a malfunction has occurred in the
ABS.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment front
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves and Check Valve.
On the outside, the relay box containing a motor relay and
a valve relay is installed.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper can be reduced smoothly.
Plunger Pump: Feeds the brake fluid held in the reservoir
to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU.
Check Valve: Controls the brake fluid flow.
ABS Warning Light
821RW033Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº warning light will illuminate if a malfunction in
the Anti-lock Brake System is detected by the Electronic
Hydraulic Control Unit (EHCU). In case of an electronic
malfunction, the EHCU will turn ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is to the ªONº position.
If the ªABSº light stays ªONº after the ignition switch is the
ªONº position, or comes ªONº and stays ªONº while
driving, the Anti-lock Brake System should be inspected
for a malfunction according to the diagnosis procedure.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached
to the knuckle on the front wheels and to the axle shaft
bearing holder on the rear wheels.
The rotor is press-fit in the axle shaft.The flux generated from electrodes magnetized by a
magnet in the sensor varies due to rotation of the rotor,
and the electromagnetic induction generates alternating
voltage in the coil. This voltage draws a ªsine curveº with
the frequency proportional to rotor speed and it allows
detection of wheel speed.
G-Sensor
The G-sensor installed inside the center console detects
the vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power assisted
brake system. However, with the detection of wheel
lock-up, a slight bump or kick-back will be felt in the brake
pedal. This pedal ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue until there is no
longer a need for the anti-lock function or until the vehicle
is stopped. A slight ticking or popping noise may be heard
during brake applications when the Anti-lock features is
being used.
When the Anti-lock feature is being used, the brake pedal
may rise even as the brakes are being applied. This is
also normal. Maintaining a constant force on the pedal
will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System may
be stopped by applying normal force to the brake pedal.
Although there is no need to push the pedal beyond the
point where it stops or holds the vehicle, by applying more
force the pedal will continue to travel toward the floor.
This extra brake pedal travel is normal.
Acronyms and Abbreviations
Several acronyms and abbreviations are commonly used
throughout this section:
ABS
Anti-lock Brake System
CKT
Circuit
DLC
Data Link Connector
EHCU
Electronic Hydraulic Control Unit
FL
Front Left

5A±5 BRAKE CONTROL SYSTEM
FR
Front Right
GEN
Generator
MV
Millivolts
RL
Rear Left
RR
Rear RightRPS
Revolution per Second
VDC
Volts DC
VA C
Volts AC
W/L
Warning Light
WSS
Wheel Speed Sensor
General Diagnosis
General Information
ABS malfunction can be classified into two types, those
which can be detected by the ABS warning light and those
which can be detected as a vehicle abnormality by the
driver.
In either case, locate the fault in accordance with the
ªBASIC DIAGNOSTIC FLOWCHARTº and repair.
Please refer to Section 5C for the diagnosis of
mechanical troubles such as brake noise, brake judder
(brake pedal or vehicle vibration felt when braking),
uneven braking, and parking brake trouble.
ABS Service Precautions
Required Tools and Items:

Box Wrench

Brake Fluid

Special Tool
Some diagnosis procedures in this section require the
installation of a special tool.
J-39200 High Impedance Multimeter
When circuit measurements are requested, use a circuit
tester with high impedance.
Computer System Service Precautions
The Anti-lock Brake System interfaces directly with the
Electronic Hydraulic Control Unit (EHCU) which is a
control computer that is similar in some regards to the
Powertrain Control Module. These modules are designed
to withstand normal current draws associated with
vehicle operation. However, care must be taken to avoid
overloading any of the EHCU circuits. In testing for opens
or shorts, do not ground or apply voltage to any of the
circuits unless instructed to do so by the appropriate
diagnostic procedure. These circuits should only be
tested with a high impedance multimeter (J-39200) or
special tools as described in this section. Power should
never be removed or applied to any control module with
the ignition in the ªONº position.
Before removing or connecting battery cables, fuses or
connectors, always turn the ignition switch to the ªOFFº
position.
General Service Precautions
The following are general precautions which should be
observed when servicing and diagnosing the Anti-lock
Brake System and/or other vehicle systems. Failure toobserve these precautions may result in Anti-lock Brake
System damage.

If welding work is to be performed on the vehicle using
an electric arc welder, the EHCU and valve block
connectors should be disconnected before the
welding operation begins.

The EHCU and valve block connectors should never
be connected or disconnected with the ignition ªONº .

EHCU of the Anti-lock Brake System are not
separately serviceable and must be replaced as
assemblies. Do not disassemble any component
which is designated as non-serviceable in this
Section.

If only rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the ªABSº warning light will
illuminate. But actually no trouble exists. After
inspection stop the engine once and re-start it, then
make sure that the ªABSº warning light does not
illuminate.
If the battery has been discharged
The engine may stall if the battery has been completely
discharged and the engine is started via jumper cables.
This is because the Anti-lock Brake System (ABS)
requires a large quantity of electricity. In this case, wait
until the battery is recharged, or set the ABS to a
non-operative state by removing the fuse for the ABS
(40A). After the battery has been recharged, stop the
engine and install the ABS fuse. Start the engine again,
and confirm that the ABS warning light does not light.
Note on Intermittents
As with virtually any electronic system, it is difficult to
identify an intermittent failure. In such a case duplicating
the system malfunction during a test drive or a good
description of vehicle behavior from the customer may be
helpful in locating a ªmost likelyº failed component or
circuit. The symptom diagnosis chart may also be useful
in isolating the failure. Most intermittent problems are
caused by faulty electrical connections or wiring. When
an intermittent failure is encountered, check suspect
circuits for:

Suspected harness damage.

Poor mating of connector halves or terminals not fully
seated in the connector body (backed out).

Improperly formed or damaged terminals.

5A±6
BRAKE CONTROL SYSTEM
Test Driving ABS Complaint Vehicles
In case that there has been an malfunction in the lighting
pattern of ªABSº warning light, the fault can be located in
accordance with the ªDIAGNOSIS BY ªABSº WARNING
LIGHT ILLUMINATION PATTERNº . In case of such
trouble as can be detected by the driver as a vehicle
symptom, however, it is necessary to give a test drive
following the test procedure mentioned below, thereby
reproducing the symptom for trouble diagnosis on a
symptom basis:
1. Start the engine and make sure that the ªABSº W/L
goes OFF. If the W/L remains ON, it means that the
Diagnostic Trouble Code (DTC) is stored. Therefore,
read the code and locate the fault.
2. Start the vehicle and accelerate to about 30 km/h (19
mph) or more.
3. Slowly brake and stop the vehicle completely.
4. Then restart the vehicle and accelerate to about 40
km/h (25 mph) or more.
5. Brake at a time so as to actuate the ABS and stop the
vehicle.
6. Be cautious of abnormality during the test. If the W/L
is actuated while driving, read the DTC and locate the
fault.
7. If the abnormality is not reproduced by the test, make
best efforts to reproduce the situation reported by the
customer.
8. If the abnormality has been detected, repair in
accordance with the ªSYMPTOM DIAGNOSISº .NOTE:

Be sure to give a test drive on a wide, even road with
little traffic.

If an abnormality is detected, be sure to suspend the
test and start trouble diagnosis at once.
ªABSº Warning Light
When ABS trouble occurs and actuates when possible
the ªABSº warning light, the trouble code corresponding
to the trouble is stored in the EHCU. Only the ordinary
brake system is available when the ABS is turned off.
When the ªABSº warning light is actuated, if the starter
switch is set ON after setting it OFF once, the EHCU
checks up on the entire system and, if there is no
abnormality, judges ABS to work currently and the
warning light works normally even though the trouble
code is stored.
NOTE: Illumination of the ªABSº warning light indicates
that anti-lock braking is no longer available. Power
assisted braking without anti-lock control is still available.
Normal Operation
ªABSº Warning Light
When the ignition is first moved from ªOFFº to ªRUNº , the
amber ªABSº warning light will turn ªONº . The ªABSº
warning light will turn ªONº during engine starting and will
usually stay ªONº for approximately three seconds after
the ignition switch is returned to the ªONº position. The
warning light should remain ªOFFº at all other times.
Basic Diagnostic Flow Chart
StepActionYe sNo
11. Customer complaint.
2. Questioning to customer.
3. Basic inspection (Refer to ªBasic inspection procedureº)
Using TECH 2?
Go to Step 2Go to Step 4
2Make sure of DTC by mode ªF0: Diagnostic Trouble Codesº.
Is EHCU including DTC?
Go to Step 3Go to Step 5
31. Repair of faulty part.
2. Elimination of DTC.
3. Inspection of ªABSº W/L Illumination pattern with ignition SW
ªONº.
4. Test drive.
Does repeat trouble?
Repeat the
diagnosis it the
symptom or DTC
appears again Go
to Step 1
Go to Step 5
4Check if the DTC is stored.
Is EHCU including DTC?
Go to Step 3
Trouble diagnosis
based on
symptom (Refer
to ªSYMPTOM
DIAGNOSISº) Go
to Step 3
51. Reconnect all components and ensure all component are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
FinishedGo to Step 5

5A±7 BRAKE CONTROL SYSTEM
Basic Inspection Procedure
1. Basic Inspection of System Brake
StepActionYe sNo
1Is the fluid level normal?
Go to Step 2
Replenish with
fluid.
Go to Step 2
2Does fluid leak?Repair.
Go to Step 3
Go to Step 3
3Is the booster functioning normal?
Go to Step 4
Repair.
Go to Step 4
4Is the pad and rotor normal?
Go to Step 5
Repair.
Go to Step 5
5Reconnect all components and ensure all component are
properly mounted.
Was this step finished?
FinishedGo to Step 5
2. Inspection of Front Axle Switch
StepActionYe sNo
1Turn the key switch on and shift the T/F to 4WD position.
Does the 4WD light come on?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2
3. Ground Inspection
StepActionYe sNo
1Are ABSÐrelated ground points ok?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2

5A±11 BRAKE CONTROL SYSTEM
Data List
DisplayContentOK/NG Criteria for Data
Battery VoltageVoltage
Between 10-16.9V
Brake Light SwitchOpen/Close
Open(0V) when pedal is released

Closed(12V) when pedal is depressed.
Front Left Wheel Speed
Front Right Wheel Speed
Rear Left Wheel Speed
Rear Right Wheel SpeedMPH(km/h)
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.
Wheel Sensor StatusOK/NG
To be OK usually
G-sensorLow/High
To be Low usually
Transfer Monitor(TOD)2 Wheel Drive
4 Wheel Drive
When 2WD: 2 Wheel Drive

When 4WD: 4 Wheel Drive
Off-Road Switch
(Transmission Input)
Active/Inactive
When shift lever position is 1, 2 and R: Active (M/T)
(Transmission Input)
When shift lever position is L and R: Active (A/T)
Valve RelayActive/Inactive
To be Active usually
ABS StateON/OFF
To be OFF usually
ABS RelayActive/Inactive
To be Active usually
Return Pump RelayActive/Inactive
To be Inactive usually
Front Left Isolation ValveActive/Inactive
To be Inactive usually
Front Left Dump Valve
Front Right Isolation Valve
Front Right Dump Valve
Rear Isolation Valve
Rear Dump Valve
ABS Warning LampON/OFF
To be ON usually (while engine stopped)