6E-50 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Scan Tool Data Definitions
This information will assist in emission or driveability
problems. The displays can be viewed while the vehicle
is being driven. Always perform the Diagnostic System
Check - Engine Controls first. The Diagnostic System
Check will confirm proper system operation.
Engine Speed
This parameter displays the rotational speed of the
crankshaft as calculated by the ECM based on inputs
from the crankshaft position (CKP) sensor or camshaft
position (CMP) sensor.
Desired Idle Speed
This parameter displays the idle speed requested by
the ECM. The ECM will change desired idle speed
based on engine coolant temperature and other inputs.
Calculate Engine Load
This parameter displays the engine load in percent
based on inputs to the ECM from various engine
sensors. The scan tool will display a lower percentage
when the engine is at idle with little or no load. The
scan tool will display a higher percentage when the
engine is running at high engine speed under a heavy
load.
Coolant Temperature
This parameter displays the temperature of the engine
coolant as calculated by the ECM using the signal from
the engine coolant temperature (ECT) sensor. The
scan tool will display a low temperature when the ECT
sensor signal voltage is high, and a high temperature
when the ECT sensor signal voltage is low.
Engine Coolant Temperature Sensor
This parameter displays the voltage signal sent to the
ECM from the engine coolant temperature (ECT)
sensor. ECT sensor is a range of value indicating a low
voltage when the temperature is high, and a high
voltage when the temperature is low.
Intake Air Temperature
This parameter displays the temperature of the intake
air as calculated by the ECM using the signal from the
intake air temperature (IAT) sensor. The scan tool will
display a low temperature when the IAT sensor signal
voltage is high, and a high temperature when the IAT
sensor signal voltage is low. Intake Air Temperature Sensor
This parameter displays the voltage signal sent to the
ECM from the intake air temperature (IAT) sensor. IAT
sensor is a range of value indicating a low voltage
when the temperature is high, and a high voltage when
the temperature is low.
Fuel Temperature
This parameter displays the temperature of the fuel as
calculated by the ECM using the signal from the fuel
temperature (FT) sensor. The scan tool will display a
low temperature when the FT sensor signal voltage is
high, and a high temperature when the FT sensor
signal voltage is low.
Fuel Temperature Sensor
This parameter displays the voltage signal sent to the
ECM from the fuel temperature (FT) sensor. FT sensor
is a range of value indicating a low voltage when the
temperature is high, and a high voltage when the
temperature is low.
MAF (Mass Air Flow)
This parameter displays the air flow into the engine as
calculated by the ECM based on the mass air flow
(MAF) sensor input. The scan tool will display a high
value at higher engine speeds, and a low value at lower
engine speed.
MAF Sensor (Mass Air Flow)
This parameter displays the voltage signal sent to the
ECM from the mass air flow (MAF) sensor. MAF sensor
is a range of value indicating a low voltage at lower
engine speed, and a high voltage at a higher engine
speeds.
Barometric Pressure
This parameter displays the barometric pressure
(BARO) as calculated by the ECM using the signal from
the BARO sensor. The scan tool will display a low
barometric pressure in high altitude area.
Barometric Pressure Sensor
This parameter displays the voltage signal sent to the
ECM from the barometric pressure (BARO) sensor.
BARO sensor is a range of value indicating a low
voltage in high altitude area, and a middle voltage in
sea level.
Immobilizer Signal Yes/ NoYes Yes
Security Wait Time Inactive/ Time
(hour: minute: second) Inactive
Inactive
Scan Tool Parameter Units Displayed Typical Data Value at Engine Idle Typical Data Value at 2000RPM
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-53
Cam/ Crank Sensor Signal/ Synchronization Status
This parameter displays the synchronization state of
the crankshaft position (CKP) sensor signal and
camshaft position (CMP) sensor signal. Asynchronous
indicates the CMP sensor signal is not detected or only
CKP sensor signal is detected. No Crank Signal
indicates CMP sensor signal is detected but CKP
sensor signal is not detected. Synchronous indicates
both sensor signals are detected correctly.
Engine Runtime
This parameter displays the time elapsed since the
engine start. The scan tool will display the time in
hours, minutes and seconds. The engine run time will
reset to zero as soon as the ignition switch is OFF.
Vehicle Speed
This parameter indicates the vehicle speed calculated
by the ECM using the signal from the vehicle speed
sensor (VSS). The scan tool will display a low value at
lower vehicle speeds, and a high value at higher
vehicle speeds.
Transmission Gear
This parameter displays the estimated transmission
gear position as calculated by the ECM based on
inputs from the vehicle speed and the engine speed.
Starter Switch
This parameter displays the input status of the starter
switch to the ECM. When the ignition switch is turned at
START position, the scan tool displays On.
Ignition Switch
This parameter displays the input status of the ignition
switch to the ECM. When the ignition switch is turned
ON position, the scan tool displays On.
Ignition Voltage
This parameter displays the ignition voltage measured
at the ignition feed circuit of the ECM. Voltage is
applied to the ECM when the ignition switch is ON
position.
Battery Voltage
This parameter displays the battery voltage measured
at the ECM main relay switched voltage feed circuit of
the ECM. Voltage is applied to the ECM when the ECM
main relay is energized.
Fuel Pump Relay Command
This parameter displays the commanded state of the
fuel pump relay control circuit. On indicates the fuel
pump relay control circuit is being grounded by the
ECM, allowing fuel pumping from the tank.
Swirl Control Solenoid Command
This parameter displays the commanded state of the
swirl control solenoid control circuit. On indicates the
swirl control solenoid control circuit is being grounded
by the ECM, allowing vacuum pressure to the swirl
control
actuator. Fuel Filter Switch
This parameter displays the input state of the fuel
pressure switch to the ECM. When the large vacuum
pressure is generated in the fuel suction line such as
clogged fuel filter, the scan tool displays Off.
A/C Request Signal
This parameter displays the input state of the air
conditioning (A/C) request to the ECM from the
heating, ventilation, and air conditioning (HVAC)
controls. When the HVAC system is requesting to
ground the A/C compressor clutch, the scan tool
displays On.
A/C Relay Command
This parameter displays the commanded state of the A/
C compressor relay control circuit. On indicates the A/C
compressor relay control circuit is being grounded by
the ECM, allowing voltage to the A/C compressor.
Park/ Neutral Switch
This parameter displays the input state of the neutral
switch to the ECM. When the transmission gear is Park
or Neutral, the scan tool displays Neutral.
Glow Relay Command
This parameter displays the commanded state of the
glow relay control circuit. On indicates the glow relay
control circuit is being grounded by the ECM, allowing
voltage to the glow plugs.
Glow Plug Lamp Command
This parameter displays the commanded state of the
glow indicator lamp control circuit. The glow indicator
lamp should be On when the scan tool indicates
command On. The glow indicator lamp should be Off
when the scan tool indicates command Off.
Brake Switch 1
This parameter displays the input state of the brake
pedal switch 1 to the ECM. When the brake pedal is
depressed, scan tool displays Applied.
Brake Switch 2
This parameter displays the input state of the brake
pedal switch 2 to the ECM. When the brake pedal is
depressed, scan tool displays Applied.
Clutch Pedal Switch
This parameter displays the input state of the clutch
pedal switch to the ECM. When the clutch pedal is
depressed, scan tool displays Applied.
Cruise Main Lamp Command
This parameter displays the commanded state of the
cruise main lamp control circuit. The cruise main lamp
should be On when the scan tool indicates command
On. The cruise main lamp should be Off when the scan
tool indicates command Off.
Cruise Main Switch
This parameter displays the input state of the cruise
main switch to the ECM. When the Cruise Main switch
is pushed, the scan tool displays On.
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ISUZU KB P190 2007
6E-54 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Cruise Cancel Switch
This parameter displays the input state of the cruise
cancel switch to the ECM. When the Cruise Cancel
switch is applied, the scan tool displays Off.
Cruise Resume Switch
This parameter displays the input state of the cruise
resume/accel. switch to the ECM. When the Cruise
Resume/Accel. switch is applied, the scan tool displays
On.
Cruise Set Switch
This parameter displays the input state of the cruise
set/coast switch to the ECM. When the Cruise Set/
Coast switch is pushed, the scan tool displays On.
MIL Command (Malfunction Indicator Lamp)
This parameter displays the commanded state of the
malfunction indicator lamp (MIL) control circuit. The
MIL should be On when the scan tool indicates
command On. The MIL should be Off when the scan
tool indicates command Off.
SVS Lamp Command (Service Vehicle Soon)
This parameter displays the commanded state of the
service vehicle soon (SVS) lamp control circuit. The
SVS lamp should be On when the scan tool indicates
command On. The SVS lamp should be Off when the
scan tool indicates command Off.
Limp Home Mode
This parameter indicates the state of the limp-home
mode. None indicates limp-home mode is not applied.
1, 2, 3 and 4 indicates fuel injection quantity reduction
is applied. 2 or higher number inhibits pilot injection. If 4
is indicated, engine running will be stopped when the
vehicle speed is less than 5 km/h (3 MPH) for 5
seconds.
Distance While MIL is Activated
This parameter displays the mileage since the
malfunction indicator lamp (MIL) is turned ON.
Engine Runtime With MIL Active
This parameter displays the engine run time elapsed
since the malfunction indicator lamp (MIL) is turned
ON. The scan tool will display the time in minutes.
Total Engine Overspeed Event
This parameter indicates counter of engine overspeed
event. Counter will be zero if any DTC is cleared.
Total Engine Coolant Overtemperature Event
This parameter indicates counter of engine overheat
event. The counter is active if engine coolant is over
11 0 °C (230 °F). Counter will be zero if any DTC is
cleared. Total Fuel Temperature Overtemperature Event
This parameter indicates counter of fuel temperature
excessively high condition. The counter is active if fuel
temperature is over 95 °C (203 °F). Counter will be zero
if any DTC is cleared.
Total Intake Air Temperature Overtemperature
Event
This parameter indicates counter of intake air
temperature excessively high condition. The counter is
active if intake air temperature is over 55 °C (131 °F).
Counter will be zero if any DTC is cleared.
Immobilizer Function Programmed
This parameter displays the state of the immobilizer
function programming in the ECM. The scan tool will
display Yes or No. Yes indicates the immobilizer
security information is correctly programmed in the
ECM. No indicates the ECM is not programmed or
ECM is reset.
Wrong Immobilizer Signal
This parameter displays the input state of the received
response signal to the ECM. When the ECM received
wrong response signal from the immobilizer control unit
(ICU), the scan tool displays Yes.
Immobilizer Signal
This parameter displays the input state of the response
signal to the ECM. When the ECM received any
response signal from the immobilizer control unit (ICU),
the scan tool displays Yes.
Security Wait Time
This parameter displays the security wait time length in
the ECM. Inactive indicates not in security wait time.
Time indicates under security wait time. This wait time
stage will prevent any further attempts to enter the
security code until the wait time has elapsed. The wait
time will increase each time an incorrect security code
is entered. Note that this parameter is not count
downed. It keeps displaying the same time until that
wait time has elapsed. The ignition switch must be kept
at ON position during the wait time period.
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-57
Scan Tool Does Not Communicate with CAN Device
Circuit Description
The ECM, transmission control module (TCM) (AISIN
A/T only) and immobilizer control unit (ICU) all
communicate with the scan tool over the controller area
network (CAN) link. The ECM, TCM, ICU and the data
recording module (DRM) communicate with each other
over the same CAN link. If no immobilizer system is
installed, the instrument panel (IP) cluster has a CAN
terminating resistor instead of the ICU.
Diagnostic Aids
The following conditions will cause a loss of CAN serial
data communication between the TCM and ICU or
between the scan tool and any control module: • A CAN serial data circuit open
• A CAN serial data circuit shorted to ground
• A CAN serial data circuit shorted to voltage
• An internal condition within a module or connector on the CAN serial data circuit, that causes a short
to voltage or ground to the CAN serial data circuit
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Scan Tool Does Not Communicate with CAN Device
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 Important
: Make sure the CANdi module is not
malfunctioning. When functioning properly, the
CANdi module LED will be flashing. In the event of
a problem, the LED will be continually illuminated
or not illuminated.
1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Attempt to establish communication with the listed control modules.
•ECM
• Immobilizer Control Unit (ICU) (If so equipped)
• Transmission control module (TCM) (AISIN A/T only)
Does the scan tool communicate with any of the
listed control modules? —
Go to Step 3 Go to Step 7
3 Does the scan tool communicate with the ECM?
—
Go to Step 4 Go to Lost
Communication with
The Engine Control Module (ECM)
4 Notice:
If no AISIN automatic transmission is
installed, skip to Step 5.
Does the scan tool communicate with the TCM? —
Go to Step 5 Go to Diagnostic
System Check -
Transmission Controls
5 Notice:
If no immobilizer system is installed, skip to
Step 6.
Does the scan tool communicate with the ICU? —
Go to Step 6 Go to Diagnostic
System Check -
Immobilizer Controls
6 Test the CAN Low and High serial data circuit for an
intermittently short to ground or intermittently short
to voltage. Then, test the CAN Low and High serial
data circuit for an intermittently open (based on
which control module did not communicate) at the
connection in the circuit.
Did you find and correct the condition? —
Go to Step 19 System OK
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ISUZU KB P190 2007
6E-58 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
71. Inspect for an intermittent, for poor
connections and for corrosion at the data link
connector (DLC) (pins 6 and 14 of B-58).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 19 Go to Step 8
8 Notice:
If no data recording module (DRM) is
installed, skip to Step 9.
1. Turn OFF the ignition.
2. Disconnect the DRM C-139 harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Attempt to communicate with the ECM, TCM and ICU.
Does the scan tool communicate with the ECM,
TCM and ICU? —
Go to Step 14 Go to Step 9
9 1. Turn OFF the ignition.
2. Reconnect the DRM harness connector if disconnected.
3. Disconnect the ECM J1 (E-90) and J2 (C-58) harness connectors.
4. Turn ON the ignition, with the engine OFF.
5. Attempt to communicate with the TCM and ICU.
Does the scan tool communicate with the TCM and
ICU? —
Go to Step 15 Go to Step 10
10 Notice:
If no AISIN automatic transmission is
installed, skip to Step 11.
1. Turn OFF the ignition.
2. Reconnect the ECM J1 (E-90) and J2 (C-58) harness connectors.
3. Disconnect the TCM C-94 and C-95 harness connectors.
4. Turn ON the ignition, with the engine OFF.
5. Attempt to communicate with the ECM and ICU.
Does the scan tool communicate with the ECM and
ICU? —
Go to Step 16 Go to Step 11
11 Notice:
If no immobilizer system is installed, skip to
St ep 1 2.
1. Turn OFF the ignition.
2. Reconnect the ECM J1 (E-90) and J2 (C-58) harness connectors if disconnected.
3. Reconnect the TCM C-94 and C-95 harness connectors if disconnected.
4. Disconnect the ICU B-68 harness connector.
5. Turn ON the ignition, with the engine OFF.
6. Attempt to communicate with the ECM and TCM.
Does the scan tool communicate with the ECM and
TCM? —
Go to Step 17 Go to Step 13
Step
Action Value(s)Yes No
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-59
121. Turn OFF the ignition.
2. Reconnect the ECM J1 (E-90) and J2 (C-58) harness connectors if disconnected.
3. Reconnect the TCM C-94 and C-95 harness connectors if disconnected.
4. Disconnect the instrument panel (IP) cluster B-23 and B-24 harness connector.
5. Turn ON the ignition, with the engine OFF.
6. Attempt to communicate with the ECM and TCM.
Does the scan tool communicate with the ECM and
TCM? —
Go to Step 18 Go to Step 13
13 Repair the open circuit, short to ground or short to
voltage on the CAN Low or High serial data circuit
between the DLC and ECM, TCM, ICU, DRM or IP
cluster.
Did you complete the repair? —
Go to Step 19
—
14Replace the DRM. Refer to DRM Replacement.
Did you complete the replacement? —
Go to Step 19—
15Important
: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 19
—
16Important
: Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 19
—
17Important
: Replacement ICU must be
programmed.
Replace the ICU. Refer to ICU Replacement.
Did you complete the replacement? —
Go to Step 19
—
18Replace the IP cluster. Refer to IP Cluster
Replacement.
Did you complete the replacement? —
Go to Step 19
—
19Attempt to establish communication with the ECM,
TCM and ICU.
Does the scan tool communicate with the ECM,
TCM and ICU? —
System OK Go to Step 2
Step
Action Value(s)Yes No
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ISUZU KB P190 2007
6E-60 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Lost Communication with The Engine Control Module (ECM)
Circuit Description
The ECM, transmission control module (TCM) (AISIN
A/T only) and immobilizer control unit (ICU) all
communicate with the scan tool over the controller area
network (CAN) link. The ECM, TCM, ICU and the data
recording module (DRM) communicate with each other
over the same CAN link. If no immobilizer system is
installed, the instrument panel (IP) cluster has a CAN
terminating resistor instead of the ICU. Schematic Reference:
Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Lost Communication with The Engine Control Module (ECM)
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 Attempt to establish communication with the ECM.
Does the scan tool communicate with the ECM? —Go to Intermittent
Conditions Go to Step 3
3 Check the ECM C-58 and E-90 connectors for poor
connections.
Did you find and correct the condition? —
Go to Step 16 Go to Step 4
4 1. Check the ECM (40A) slow blow fuse, ECM
(B) (10A) fuse and Engine (10A) fuse.
Replace and retest if open. If any fuse
continues to open, repair the short to ground
on each circuit fed by that fuse.
2. Turn OFF the ignition.
3. Disconnect the ECM C-58 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. Connect a test lamp to ground and check for voltage at the ignition voltage supply circuit at
the ECM (pin 72 of C-58).
Does the test lamp illuminate? —
Go to Step 5 Go to Step 13
5 1. Turn OFF the ignition.
2. Disconnect the scan tool from the data link connector (DLC) if connected.
3. Measure the resistance across the CAN Low and High circuits by probing the DLC (pins 6
and 14 of B-58).
Is the resistance within the specified value (parallel
resistance of the 120 Ω resistor in the ECM and the
120 Ω resistor in the ICU or IP cluster should be
60 Ω)? 50 to 70
Ω
Go to Step 7 Go to Step 6
6 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 66 and 67 of C-
58).
4. Test for high resistance on each circuit.
5. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-61
71. Check ECM ground for corrosion and
tightness.
2. Clean or tighten grounds as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 8
8 1. Turn OFF the ignition.
2. Reconnect the ECM harness connector if disconnected.
3. Replace the ECM main relay with the heater relay or replace with a known good relay.
4. Turn ON the ignition, with the engine OFF.
5. Attempt to establish communication with the ECM.
Does the scan tool communicate with the ECM? —
Go to Step 14 Go to Step 9
9 1. Turn OFF the ignition.
2. Remove the ECM main relay.
3. Turn ON the ignition, with the engine OFF.
4. Using a test lamp, check for both voltage supply circuits to the ECM main relay (pins 4
and 5 of X-12).
5. Repair the open circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 10
10 1. Reinstall the ECM main relay.
2. Turn the ignition ON and OFF while listening of feeling for the ECM main relay click. Wait 7
seconds between transitions.
Does the ECM main relay click when the ignition
switch is turned ON or OFF? —
Go to Step 12 Go to Step 11
11 Repair the ECM main relay ground circuit between
the ECM main relay (pin 2 of X-12) and engine
room ground terminal (C-36) for the following
conditions: •An open circuit
• High resistance or a poor connection at the
ECM main relay or ground terminal
Did you complete the repair? —
Go to Step 16
—
121. Test the battery voltage circuit between the
ECM (pin 73 of C-58) and the ECM main relay
(pin 1 of X-12) for the following conditions:
• An open circuit
• High resistance or a poor connection at ECM or ECM main relay
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15
13 Repair the open in the ignition voltage circuit to the
ECM.
Did you complete the repair? —
Go to Step 16
—
14Replace the ECM main relay.
Did you complete the replacement? —
Go to Step 16—
Step Action Value(s)Yes No
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ISUZU KB P190 2007