2007 ISUZU KB P190 Wiring harness

5A-30 BRAKE CONTROL SYSTEM
4. Release the brake pedal.
5. Make sure that the front left hold solenoid valve "ON" aimed at by Tech 2 and the wheel locked
position are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.

Front Left Release Valve Test
Purpose: The purpose of this test is to detect brake pipe
and valve line harness wire for incorrect connections and
valve problem.
This test will help you confirm the result of your repai
r
service including the removal/ reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the "ON" position
with the four wheels lifted up. The brake pedal is stepped
on, released and stepped on again with the parking
brake released.

Test Procedure: 1. Connect Tech 2 with the vehicle, and select "Actuator Test" menus.
2. Select a "Front Left Release Valve Test" menu from the "Actuator Test" menus.
3. Step on the brake pedal.
4. Make sure that the front left release solenoid valve "ON" aimed at by Tech 2 and the wheel released
position are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.

Front Right Hold Valve Test
Purpose: The purpose of this test is to detect brake pipe
and valve line harness wire for incorrect connections and
valve problem.
This test will help you confirm the result of your repai
r
service including the removal/ reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the "ON" position
with the four wheels lifted up. The brake pedal is stepped
on, released and stepped on again with the parking
brake released.

Test Procedure: 1. Connect Tech 2 with the vehicle, and select "Actuator Test" menus.
2. Select a "Front Right Hold Valve Test" menu from the "Actuator Test" menus.
3. Step on the brake pedal.
4. Release the brake pedal.
5. Make sure that the front right hold solenoid valve "ON" aimed at by Tech 2 and the wheel locked
position are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.

Front Right Release Valve Test
Purpose: The purpose of this test is to detect brake pipe
and valve line harness wire for incorrect connections
and valve problem.
This test will help you confirm the result of your repai
r
service including the removal/ reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the "ON" position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.

Test Procedure: 1. Connect Tech 2 with the vehicle, and selec
t
"Actuator Test" menus.
2. Select a "Front Right Release Valve Test" menu from the "Actuator Test" menus.
3. Step on the brake pedal.
4. Make sure that the front right release solenoid valve "ON" aimed at by Tech 2 and the wheel released
position are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.

Rear Hold Valve Test
Purpose: The purpose of this test is to detect brake pipe
and valve line harness wire for incorrect connections
and valve problem.
This test will help you confirm the result of your repai
r
service including the removal/ reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the "ON" position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.

Test Procedure: 1. Connect Tech 2 with the vehicle, and selec
t
"Actuator Test" menus.


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ISUZU KB P190 2007

BRAKE CONTROL SYSTEM 5A-31
2. Select a "Rear Hold Valve Test" menu from the
"Actuator Test" menus.
3. Step on the brake pedal.
4. Release the brake pedal.
5. Make sure that the rear hold solenoid valve "ON" aimed at by Tech 2 and the wheel locked position
are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.

Rear Release Valve Test
Purpose: The purpose of this test is to detect brake pipe
and valve line harness wire for incorrect connections and
valve problem.
This test will help you confirm the result of your repai
r
service including the removal/ reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the "ON" position
with the four wheels lifted up. The brake pedal is stepped
on, released and stepped on again with the parking
brake released.

Test Procedure: 1. Connect Tech 2 with the vehicle, and select "Actuator Test" menus.
2. Select a "Rear Release Valve Test" menu from the "Actuator Test" menus.
3. Step on the brake pedal.
4. Make sure that the rear release solenoid valve "ON" aimed at by Tech 2 and the wheel released position
are the same.
If different, check brake pipe, valve line harness wiring
and hydraulic unit. Repair is needed if abnormality is
found.


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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-157
DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Circuit Description
The vehicle speed sensor (VSS) is used by the engine
control module (ECM) and speedometer, which
generates a speed signal from the transmission output
shaft. The VSS has the following circuits.
• Ignition voltage feed circuit
• VSS signal circuit
• VSS low reference circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The 12 volts
operating supply from the Meter fuse (except 2W D with
A/T) or Back Up fuse (2W D with A/T). The ECM
calculates the vehicle speed by the VSS. If the vehicle
is 2W D with automatic transmission, VSS signals are
sent from the transmission control module (TCM). If the
ECM detects VSS signals are generated with high
frequencies, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the vehicle speed is highe
r
than 200 km/h (125 MPH) for 5 seconds.
(Symptom Code 1)

•
The ECM detects that the vehicle speed senso
r
signal frequency is too high for 0.6 seconds.
(Symptom Code A)
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses a vehicle speed substitution of 5
km/h (3 MPH) for engine control.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.

DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Chart for 2WD with A/T
Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Inspect all of the circuits going to the automatic transmission (A/T) vehicle speed sensor (VSS)
for the following: • Routed too closely to fuel injection solenoid
wiring or components
• Routed too closely to after-market add-on
electrical equipment
• Routed too closely to solenoids, relays, and
motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? 

Go to Step 7 Go to Step 3
3 1. Turn OFF the ignition. 2. Disconnect the A/T VSS harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the A/T
VSS (pins 1, 2 and 3 of E-30 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 4

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ISUZU KB P190 2007

6E-158 Engine Control System (4JH1)
Step Action Value(s) Yes No
4 1. Turn OFF the ignition.
2. Disconnect the engine control module (ECM) harness connector.
3. Inspect for an intermittent and for a poor connection on A/T VSS circuit at the harness
connector of the ECM (pin 68 of C-56 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 5
5 1. Remove the A/T VSS. Refer to A/T Speed Sensor Replacement in automatic transmission
section.
2. Visually inspect the A/T VSS for the following conditions: • Physical damage
• Being loose
• Improper installation
3. The following conditions may cause this DTC to set: • Electromagnetic interference in the A/T
VSS circuits
4. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 6
6 Replace the A/T VSS. Refer to A/T Speed Sensor Replacement in automatic transmission section
Did you complete the replacement? 

Go to Step 7 
7 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Drive the vehicle.
5. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed? 

Go to Step 8 Go to Step 2
8 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK

Chart for except 2WD with A/T
Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Inspect all of the circuits going to the vehicle speed sensor (VSS) for the following: • Routed too closely to fuel injection solenoid
wiring or components
• Routed too closely to after-market add-on
electrical equipment
• Routed too closely to solenoids, relays, and
motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? 

Go to Step 7 Go to Step 3

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-255
Symptoms – Engine Controls
Symptoms – Engine Controls
Important Preliminary Inspections Before Starting
Perform Diagnostic System Check – Engine Controls
before using the symptom tables, and verify that all o
f
the following are true:
• The engine control module (ECM) and malfunction
indicator lamp (MIL) are operating correctly.
• There are no diagnostic trouble codes (DTCs)
stored, or a DTC exists but without the MIL.
• The scan tool data is within the normal operating
range. Refer to scan tool Data List in this section.
• Verify the customer concern and locate the correct
symptom in the table of contents. Inspect the items
indicated under that symptom.
Visual and Physical Inspection
Several of the symptom procedures ask for careful
visual and physical inspection. This step is extremel
y
important. The visual and physical inspection can lead
to correcting a problem without further inspections, and
can save valuable time. Ensure that:
• The ECM grounds are clean, tight, and in thei
r
proper location.
• The vacuum hoses are not split or kinked, and
properly connected. Inspect thoroughly for an
y
type of leak or restriction.
• The mass air flow (MAF) sensor is properl
y
installed. The arrows on the plastic portion of the
sensor must point toward the engine.
• The air intake ducts are not collapsed or damaged.
• There are no leaks at the MAF sensor, an
y
connections or intake manifold sealing surfaces.
• The engine harness wiring and terminals are
properly connected and are not pinched or cut.
Intermittent
Important:
Inspect for improper installation of electrical
components if an intermittent condition exists. Inspect
for aftermarket add-on electrical equipment devices,
lights, and cellular phones. Verify that no aftermarket
equipment is connected to the keyword 2000 serial data
circuit. If you cannot locate an intermittent condition, a
cellular phone communication signal may cause the
condition.
Important:
The problem may or may not turn ON the MIL or store a
DTC.

Faulty electrical connections or wiring cause most
intermittent problems. Perform a careful visual and
physical inspection of the suspect connectors for the
following conditions:
• Improperly mated connector halves
• Terminals that are not seated
• Terminals that are damaged or improperly formed
Reform or replace connector terminals in the problem
circuit in order to ensure proper contact tension.
Remove the terminal from the connector body in orde
r
to inspect for poor terminal wire connection.
Road test the vehicle with the DMM connected to the
suspected circuit. An abnormal reading that occurs
when the malfunction occurs is a good indication that
there is a malfunction in the circuit being monitored.
Use the scan tool in order to help detect intermittent
conditions. Useful features of the scan tool include the
following:
• Trigger the Snapshot feature in order to capture
and store engine parameters when the malfunction
occurs. Review this stored information in order to
see the specific running conditions that caused the
malfunction.
• Use the Plot Function on the scan tool in order to
plot selected data parameters. Review this stored
information to aid in locating an intermittent
problem. Refer to the scan tool Users Guide fo
r
more information.
Important:
If the intermittent condition exists as a start and then
stall, test for DTCs relating to the vehicle theft deterrent
system. Test for improper installation of electrical
options such as lights, cellular phones, etc.
Any of the following may cause an intermittent MIL with
no stored DTC:
• The ECM grounds are loose or dirty. Refer to
Engine Controls Schematics.
• The MIL circuit intermittently shorted to ground.
• Electrical system interference caused by a
malfunctioning relay, ECM driven solenoid, o
r
switch. The electrical component can cause a
sharp electrical surge. Normally, the problem will
occur when the malfunctioning component is
operating.
• There is an open diode across the A/C
compressor clutch or any other open diodes.



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6E-256 Engine Control System (4JH1)
Important:
The following symptom tables contain groups o
f
possible causes for each symptom. The order of these
procedures is not important. If the scan tool readings do
not indicate the problems, then proceed in a logical
order, easiest to check or most likely to cause first. In
order to determine if a specific vehicle is using a
particular system or component, refer to Engine
Controls Schematics for an application.
Use the following tables when diagnosing a symptom
complaint:
• Intermittent Conditions
• Hard Start
• Rough, Unstable, or Incorrect Idle and Stalling
• Cuts Out, Misses
• Surge/Chuggles
• Lack of Power, Sluggishness, or Sponginess
• Hesitation, Sag, Stumble
• Fuel Knock/Combustion Noise
• Poor Fuel Economy
• Excessive Smoke (Black Smoke)
• Excessive Smoke (W hite Smoke)



Intermittent Conditions
Checks Action
DEFINITION:The problem is not currently present but is indicated in DTC History.
OR
There is a customer complaint, but the symptom cannot currently be duplicated, if the problem is not DTC related.
Preliminary Checks • Refer to Symptoms – Engine Controls before starting.
Harness/Connector Many intermittent open or shorted circuits are affected by harness/connector
movement that is caused by vibration, engine torque, bumps/rough pavement, etc.
Test for this type of condition by performing the applicable procedure from the
following list:
• Move related connectors and wiring while monitoring the appropriate scan tool data.
• Move related connectors and wiring with the component commanded ON, and OFF,
with the scan tool. Observe the component operation.
• W ith the engine running, move related connectors and wiring while monitoring
engine operation.
If harness or connector movement affects the data displayed, component/system
operation, or engine operation, inspect and repair the harness/connections as
necessary.
Refer to Electrical Connections or W iring.

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-257
Checks Action
Electrical Connections or W iring Poor electrical connections, terminal tension or wiring problems cause most intermittent. To perform the following inspections:
• Inspect for poor mating of the connector halves, or terminals improperly seated in the
connector body.
• Inspect for improperly formed or damaged terminals. Test for poor terminal tension.
• Inspect for poor terminal to wire connections including terminals crimped over
insulation. This requires removing the terminal from the connector body.
• Inspect for corrosion/water intrusion. Pierced or damaged insulation can allow
moisture to enter the wiring. The conductor can corrode inside the insulation, with
little visible evidence. Look for swollen and stiff sections of wire in the suspect
circuits.
• Inspect for wires that are broken inside the insulation.
• Inspect the harness for pinched, cut or rubbed through wiring.
• Ensure that the wiring does not come in contact with hot exhaust components.
Control Module Power and Grounds
Component Power and Grounds Poor power or ground connections can cause widely varying symptoms.
• Test all control module power supply circuits. Many vehicles have multiple circuits
supplying power to the control module. Other components in the system may have
separate power supply circuits that may also need to be tested. Inspect connections
at the module/component connectors, fuses, and any intermediate connections
between the power source and the module/component. A test lamp or a DMM may
indicate that voltage is present, but neither tests the ability of the circuit to carry
sufficient current. Ensure that the circuit can carry the current necessary to operate
the component.
• Test all control module ground and system ground circuits. The control module may
have multiple ground circuits. Other components in the system may have separate
grounds that may also need to be tested. Inspect grounds for clean and tight
connections at the grounding point. Inspect the connections at the component and in
splice packs, where applicable. Ensure that the circuit can carry the current
necessary to operate the component.
Temperature Sensitivity • An intermittent condition may occur when a component/connection reaches normal
operating temperature. The condition may occur only when the
component/connection is cold, or only when the component/connection is hot.
• If the intermittent is related to heat, review the data for a relationship with the
following: - High ambient temperatures
- Under hood/engine generated heat
- Circuit generated heat due to a poor connection, or high electrical load
- Higher than normal load conditions, towing, etc.
• If the intermittent is related to cold, review the data for the following:
- Low ambient temperatures–In extremely low temperatures, ice may form in a connection or component. Test for water intrusion.
- The condition only occurs on a cold start.
- The condition goes away when the vehicle warms up.
• Information from the customer may help to determine if the trouble follows a pattern
that is temperature related.

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6E-262 Engine Control System (4JH1)
Checks Action
Additional Checks •
Electromagnetic interference (EMI) on the reference circuit can cause an engine miss
condition. The scan tool can usually detect EMI by monitoring the engine speed. A
sudden increase in speed with little change in actual engine speed change indicates that
EMI is present. If a problem exists, check routing of high voltage components, such as
fuel injection solenoid valve wiring, near the sensor circuits.
• Inspect for faulty engine mounts.
• Inspect faulty crank pulley.
• Inspect faulty generator & A/C compressor.
• Inspect the generator output voltage. Repair if less than 9 volts or more than 16 volts.
• Inspect the EGR system operating correctly.
• Inspect the A/C operation.


Cut Out, Misses
Checks Action
DEFINITION:A constant jerking that follows the engine speed, usually more pronounced as the engine load increase. The
exhaust has a steady spitting sound at idle, low speed, or hard acceleration for the fuel starvation that can cause the engine to
cut-out.
Preliminary Check • Diagnostic System Check - Engine Controls.
• Inspect that the harness connectors are correctly connected.
• Inspect the engine control module (ECM) and fuel injection pump control unit (PCU)
grounds for being clean, tight, and in their proper locations.
• Inspect the scan tool Data List in this section.
• Inspect the Service Bulletins for ECM software updates.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the scan tool
Data List in this section.
• Use the scan tool to observe the Accelerator Pedal Position. Accelerator Pedal
Position indicating angle parameter should change linearly from 0% to 100%
according to the accelerator pedal operation.
• Inspect the crankshaft position (CKP) sensor is tight and the flywheel circumference
is not damaged.

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ISUZU KB P190 2007