2007 ISUZU KB P190 check engine light

6E-250 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P156A or P156B (Flash Code 135)
Circuit Description
The ECM monitors the battery voltage on the ECM
main relay voltage feed terminal to make sure that the
voltage stays within the proper range. If the ECM
detects an excessively low or high battery voltage, DTC
P156A or P156B will set.
Condition for Running the DTC • The ignition voltage is more than 9 volts. (DTC P156B)
Condition for Setting the DTC • The ECM detects that the battery voltage feed circuit is less than 8 volts for 20 seconds. (DTC
P156A)
• The ECM detects that the battery voltage feed circuit is more than 16 volts for 5 seconds. (DTC
P156B)
Action Taken When the DTC Sets • The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (Euro 4 Specification) • The ECM illuminates the MIL when the diagnostic
runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
(Except Euro 4 Specification)
• The ECM limits fuel injection quantity. (DTC P156B)
• The ECM inhibits pilot injection. (DTC P156B)
• The ECM inhibits cruise control. (DTC P156B)
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Diagnostic Aids • A charging system problem may set this DTC.
• The weakened battery may set DTC P156A.
• Jump starting the vehicle or a battery charger may have set DTC P156B.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P156A
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. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine and let idle.
4. Load the electrical system by turning ON the headlights, A/C, etc. while observing the
Battery Voltage parameter with a scan tool.
Does the scan tool indicate more than the specified
value? 10.0 volts
Go to Diagnostic Aids Go to Step 3
3 Test the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you find a charging system problem? —
Go to Step 4 Go to Step 5
4 Repair the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you complete the repair? —
Go to Step 6
—

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-251
Circuit/ System Testing DTC P156B
51. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent, for a poor connection and for corrosion at the harness
connector of the ECM (pin 73 of C-58).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Diagnostic
Aids
6 1. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine and let idle.
5. Load the electrical system by turning ON the headlights, A/C, etc. while observing the
Battery Voltage parameter with a scan tool.
Does the scan tool indicate more than the specified
value? 10.0 volts
Go to Step 7 Go to Step 3
7 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No
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 Was the vehicle recently jump started or a battery
charger placed on the battery? —
Go to Step 7 Go to Step 3
3 1. Install a scan tool.
2. Start the engine and let idle.
3. Observe the Battery Voltage parameter with the scan tool.
Does the scan tool indicate less than the specified
value? 16.0 volts
Go to Diagnostic Aids Go to Step 4
4 Test the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you find a charging system problem? —
Go to Step 5 Go to Diagnostic
Aids
5 Repair the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you complete the repair? —
Go to Step 6
—

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-311
In-Tank Fuel Pump System Check
Description
The ECM controls the fuel pump relay, which supplies
power to the fuel pump in the fuel tank. The ECM
commands the fuel pump relay ON for a certain length
of time at ignition switch is ON with the engine OFF.
During the engine is running it is continuity commanded
ON.
In-tank Fuel Pump Control Operation • The battery voltage is more than 9 volts. • The ignition switch is ON.
• The fuel pump is commanded ON for 12 seconds at ignition switch is ON with the engine OFF.
• The fuel pump is continuously ON while engine is running.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing In-Tank Fuel Pump System Check
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. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition for 20 seconds, then start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0231 or P0232 set? —
Refer to Applicable DTC Go to Step 3
3 1. Turn OFF the ignition for 30 seconds.
2. Remove the fuel filler cap.
3. Turn ON the ignition, with the engine OFF.
Is the fuel pump operating sound heard from the
fuel filler? —
Go to Step 4 Go to Step 7
4 Does the fuel pump operating sound stop after
approximately 12 seconds passed? —
Go to Step 21 Go to Step 5
5 1. Turn OFF the ignition for 30 seconds.
2. Replace the fuel pump relay with the head light relay or replace with a known good relay.
3. Turn ON the ignition, with the engine OFF.
Does the fuel pump operating sound stop after
approximately 12 seconds passed? —
Go to Step 20 Go to Step 6
6 Repair the short to battery or ignition voltage
between the fuel pump relay (pin 2 of X-13) and the
fuel pump (pin 1 of F-2).
Did you complete the repair? —
Go to Step 25
—
71. Turn OFF the ignition for 30 seconds.
2. Replace the fuel pump relay with the head light relay or replace with a known good relay.
3. Turn ON the ignition, with the engine OFF.
Is the fuel pump operating sound heard from the
fuel filler? —
Go to Step 17 Go to Step 8
8 Inspect the Fuel Pump (10A) fuse in the engine
room fuse block.
Is the Fuel Pump (10A) fuse open? —
Go to Step 9 Go to Step 10

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ISUZU KB P190 2007

6E-314 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Cruise Control System Check
Description
The cruise control system consists of the ECM, the
cruise main switch, set/ coast switch, resume/ accel.
switch and cancel switch. The cruise control keeps the
vehicle speed at a driver's set speed. When the cruise
main switch is turned ON, signal is provided to the
ECM and the cruise main indicator lamp on the switch
will light up. When the cruise set/ coast switch is turned
ON, the switch signal is provided to the ECM and the
vehicle speed is set. The vehicle speed is increased or
decreased if the set/ coast switch or the resume/ accel.
switch is turned ON. When the cruise cancel switch is
applied, the switch signal is provided to the ECM and
the cruise control system is inactive.
Condition for Running the Cruise Control • The vehicle speed is between approximately 40 km/h (24 MPH) to 175 km/h (105 MPH).
• The engine speed is less than 4500 PRM.
• The cruise main switch is ON.
1. Function of "SET"
If the set/ coast switch is pressed and released while
condition for running the cruise control are satisfied, the
ECM memorize and maintain the vehicle speed at that
time.
2. Function of "COAST"
If the set/ coast switch is pressed while the cruise
control system is operating, the vehicle speed is
decreased. Then, when the set/ coast switch is
released, the vehicle will maintain the vehicle speed at
that time.
3. Function of "RESUME"
If the resume/ accel. switch is applied while the cruise
control system is operating and the ECM memorizes
the vehicle speed, the vehicle speed is returned to the
vehicle speed memorized by the ECM.
4. Function of "ACCEL"
If the resume/ accel. switch is applied while the cruise
control system is operating, the vehicle speed is
increased. Then, when the resume/ accel. switch is
released, the vehicle will maintain the vehicle speed at
that time.
5. Function of "TAP UP"
If the resume/ accel. switch is tapped (momentarily
applied) while the cruise control system is operating,
the vehicle speed is increased 1 km/h (0.6 MPH) at a
time. 6. Function of "TAP DOWN"
If the set/ coast switch is tapped while the cruise control
system is operating, the vehicle speed is decreased 1
km/h (0.6 MPH).
7. Function of Temporary Acceleration
If the accelerator pedal is pressed while the cruise
control system is operating, the vehicle speed is
increased.
8. Function of Temporary Cancellation
The cruise control is canceled temporarily if any of the
following condition is met:
• The cruise cancel switch is applied.
• The brake pedal is depressed.
• The clutch pedal is depressed (M/T).
• The selector lever position is not D, 3, 2 or L (A/T).
• The cruise set/ coast switch and resume/ accel. switch are ON at the same time.
• The actual vehicle speed becomes less than approximately 35 km/h (22 MPH).
• The actual vehicle speed is more than 40 km/h (24 MPH) over the set speed, or more than 10 km/h (6
MPH) over the set speed for longer than 3
minutes.
• The actual vehicle speed is more than 70 km/h (42 MPH) below the set speed, or more than 10 km/h
(6 MPH) below the set speed for 3 minutes.
By applying the resume/ accel. switch, the vehicle
speed is returned to the vehicle speed memorized by
the ECM (resume function) if within the condition for
running the cruise control are satisfied.
9. Function of Complete Cancellation
The cruise control is canceled completely if any of the
following condition is met:
• The cruise main switch is OFF.
• The ignition switch is OFF.
• The vehicle is once stopped.
• The DTCs relating to the cruise control system inhibits are set.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Cruise Control System Check (1 of 2)
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

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-323
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 of
the following are true:
• The ECM and malfunction indicator lamp (MIL)/ service vehicle soon (SVS) lamp are operating
correctly.
• 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 extremely
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 their proper location.
• The vacuum hoses are not split or kinked, and properly connected. Inspect thoroughly for any
type of leak or restriction.
• The air intake ducts are not collapsed or damaged.
• The exhaust pipes are not collapsed or damaged.
• 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 controller area network
(CAN) or other serial data circuit.
Important: The problem may or may not turn ON the
MIL/ SVS lamp 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 order
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 Tech 2 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.
• Freeze Frame/ Failure Record can also aid in locating an intermittent condition. Review and
capture the information in the Freeze Frame/
Failure Record associated with the intermittent
DTC being diagnosed. Drive the vehicle within the
conditions that were present when the DTC
originally set.
• 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 for
more information.
Use the data recording module (DRM) in order to help
detect intermittent conditions. The DRM has ability to
store engine log data when an event of DTC. Maximum
three log data can be stored in the DRM memory. If
more than maximum number of storage is set, oldest
log data is overwritten. However, if same DTC is set
within eight hours that DTC is not stored in the DRM
memory.
The manual trigger function is to store the log data by
an arbitrary operation of the driver when an event of
wrong vehicle performance that is instead of an event
of DTC. If the driver presses and releases the manual
trigger switch once, that time becomes a trigger and
one log data before and behind the trigger is stored in
the DRM memory. When there is a space in the DRM
memory, log data is stored in that space. However,
when more than maximum number of storage is set,
oldest log data is overwritten.
Refer to the DRM Users Guide for 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/
SVS lamp with no stored DTC:
• The ECM grounds are loose or dirty. Refer to Engine Controls Schematics.

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6E-326 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
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.
• Freeze Frame, Failure Records or Snapshot Data may help with this type of intermittent conditions, where applicable.
• If the intermittent is related to heat, review the data for a relationship with the following:
- High ambient temperatures.
- Underhood/ 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 aconnection 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.
Electromagnetic Interference (EMI)
and Electrical Noise Some electrical components/ circuits are sensitive to EMI or other types of electrical
noise. Inspect the following conditions:
• A misrouted harness that is too close to high voltage/ high current devices such as injection components, motors, generator etc. These components may induce
electrical noise on a circuit that could interfere with normal circuit operation.
• Electrical system interference caused by a malfunctioning relay, or the ECM driven solenoid or switch. These conditions can cause a sharp electrical surge. Normally,
the problem will occur when the malfunctioning component is operating.
• Improper installation of non-factory or aftermarket add on accessories such as lights, 2-way radios, amplifiers, electric motors, remote starters, alarm systems, cell
phones, etc. These accessories may lead to an emission related failure while in
use, but do not fail when the accessories are not in use.
• Test for any open diodes. Some relays may contain a clamping diode.
• Test the generator for a bad rectifier bridge that may be allowing AC noise into the electrical system.
Incorrect ECM Programming • There are only a few situations where reprogramming a ECM is appropriate:
- An ECM from another vehicle is installed.
- Revised software/ calibration files have been released for this vehicle.
Important: DO NOT reprogram the ECM with the SAME software/ calibration files that
are already present in the ECM. This is not an effective repair for any type of driveability
problem.
• Verify that the ECM contains the correct software/ calibration. If incorrect programming is found, reprogram the ECM with the most current software/
calibration.
Duplicating Failure Conditions • If none of the previous tests are successful, attempt to duplicate and/ or capture the failure conditions.
• Freeze Frame/ Failure Records data, where applicable, contains the conditions that were present when the DTC set.
- Review and record Freeze Frame/ Failure Records data.
- Operate the vehicle under the same conditions that were noted in Freeze Frame/ Failure Records data, as closely as possible. The vehicle must also be
operating within the Conditions for Running the DTC. Refer to Conditions for
Running the DTC in the supporting text of the DTC being diagnosed.
• An alternate method is to drive the vehicle with the DMM connected to a suspected circuit. An abnormal reading on the DMM when the problem occurs, may help you
locate the problem.
Checks
Action

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-349
4. In order to get programming approval, the on-screen displays a message to user. Get
programming approval from the TIS 2000 using
the following procedure:
a. Connect a scan tool to the terminal that installed TIS 2000 with the latest software and
the hardware key is plugged into port.
b. Turn ON the scan tool and keep at title screen.
c. Launch the TIS application.
d. Select the Security Access at the main screen.
e. Highlight the “Tech 2” on the Diagnostic Tool Selection screen and click “Next”.
f. Click “Close” on the Security Access Enabled screen.
g. Turn OFF the scan tool.
h. Disconnect the scan tool from the terminal.
5. Install a scan tool to the vehicle.
6. Turn ON the ignition, with the engine OFF.
7. Select Diagnostics > appropriate vehicle identification > 4JK1 or 4JJ1 > Programming >
Program ECU.
8. Verify the VIN on the screen if programmed at previously described SPS. If not programmed or
incorrect VIN, input correct VIN.
9. Input 24 digits of each fuel injector ID code.
10. After complete the programming, turn OFF the ignition for 30 seconds.
11. Start the engine and let idle.
12. Inspect for a proper engine running condition and for no DTC's. Refer to the Diagnostic System
Check - Engine Controls if needed.
G. Supply Pump Relearn 1. Install a scan tool.
2. Start the engine and let idle until engine coolant temperature reads 65 °C (149 °F) or higher while
observing the Supply Pump Status parameter with
a scan tool. The scan tool parameter changes
status Not Learn > Learning > Learned.
3. If the ECM has correctly learned the fuel supply pump current adjustment, the Supply Pump Status
parameter on the scan tool will repeatedly indicate
Learning and Learned.Service Programming System (SPS)
Description
The service programming system (SPS) allows a
technician to program a control module through the
data link connector (DLC). The information transfer
circuit that is used at the DLC is the same serial data
circuit used by the scan tool for retrieving DTCs,
displaying data, clearing DTCs etc. This procedure
offers the ability to install software/ calibrations
matched to a particular vehicle.
Most control modules have two types of memory. The
software/ calibrations reside in the flash memory. The
two types of memory are listed below:
• Electrically Erasable Programmable Read Only Memory (EEPROM)
This type of memory allows selected portions of
memory to be programmed while other portions
remain unchanged.
Certain learned values reside in the EEPROM,
such as:
- The vehicle identification number (VIN)
- The software/ calibrations identification numbers
- The control module security information
• Flash Read Only Memory-Flash Memory Flash memory has increased memory storage
capacity. During programming, all information
within this type of memory is erased, and then
replaced with entirely new information.
Service Programming Methods
The two methods of programming an ECM are listed
below:
• Remote Programming
• Pass Thru Programming
For information on programming an ECM using one of
the methods listed above, refer to Service
Programming System (SPS) (Remote Procedure) or
Service Programming System (SPS) (Pass-Thru
Procedure).
Before Programming a Control Module
Important: DO NOT program an existing ECM with the
identical software/ calibration package. This procedure is not
a short cut to correct the driveability condition. This is an
ineffective repair. An ECM should only be programmed when
the following occurs:
• When a service procedure instructs you to replace the ECM.
• An updated software/ calibrations is released.
Ensure that the following conditions are met before
programming an ECM:
• The scan tool PCMCIA card is programmed with the latest software.
• The TIS 2000 is installed with the latest software.

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6-2 ENGINE DIAGNOSIS (C24SE)
Engine Diagnosis
Hard Starting
1.Starting Motor Does Not Turn Over
Trouble Shooting Procedure
Turn on headlights and starter switch.
Condition Possible cause Correction
Headlights go out or dim
considerably Battery run down or under
charged Recharge or replace battery

Terminals poorly connected Clean battery posts and terminals
and connect properly
Starting motor coil circuit shorted Overhaul or replace
Starting motor defective Overhaul or replace
2.Ignition Trouble - Starting Motor Turns Over But Engine Does Not Start
Spark Test Disconnect a high tension cable from any spark plug.
Connect the spark plug tester (use commercially
available tool), crank the engine, and check if a spark is
generated in the spark plug tester. Before cranking the
engine, make sure that the spark plug tester is properly
grounded. To avoid electrical shock, do not touch the
high tension cable while the engine is running.

Condition Possible cause Correction
Spark jumps across gap Spark plug defective Clean, adjust spark gap or replace
Spark plug wire in correct Connect properly or replace
Ignition timing incorrect Refer to Ignition System
Fuel not reaching fuel injector(s)
or engine Refer to item 3 (Trouble in fuel
system)
Valve timing incorrect Adjust
Engine lacks compression Refer to item 4 (Engine lacks
compression)
No sparking takes place Ignition coil disconnected or
broken Connect properly or replace

Electronic Ignition System with
module Replace

Poor connections in engine
harness Correct

Engine Control Module cable
disconnected or defective Correct or replace


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