Isuzu KB P190. Manual — part 880

Engine Management – V6 – Diagnostics

Page 6C1-2–242

Oil Temperature Sensor: This parameter displays the engine oil temperature in degrees C.

Power Enrichment: This parameter displays the status of the operating mode of the ECM used to increase fuel delivery
during certain acceleration conditions.

Reduced Engine Power: This parameter displays when the ECM is commanding reduced engine power due to a
throttle actuator control (TAC) system condition.

Requested Torque: This parameter displays the calculated amount torque requested of the ECM by the Transmission
Control Module (TCM).

Short Term Fuel Trim (Bank 1 or Bank 2): This parameter displays the short-term correction to the fuel delivery by the
ECM in response to oxygen sensor 1 or 2. If the oxygen sensor indicates a lean air/fuel mixture, the control module will
add fuel, increasing the short term fuel trim above 0. If the oxygen sensor indicates a rich air/fuel mixture, the control
module will reduce fuel decreasing the short term fuel trim below 0.

Spark Advance: This parameter displays the amount of spark advance the ECM is commanding on the ignition control
circuits. The ECM determines the desired advance.

Starter Relay: This parameter displays the Em’s commanded state of the starter motor relay control circuit.

Starter Relay Circuit Status: This parameter displays the state of the starter relay control circuit. The parameter
displays ‘Fault’ if the starter relay control circuit is open, shorted to ground, or shorted to voltage. The parameter
displays Undefined Status’ until the circuit has been determined as being ‘OK’. This parameter may not change if Tech 2
is used to command the relay control circuit ON.

Start Up ECT (Engine Coolant Temperature): This parameter displays the temperature of the engine coolant on start
up based on input to the ECM from the ECT sensor.

Start Up IAT (Intake Air Temperature): This parameter displays the temperature of the intake air at start in the air
induction system based on input to the ECM from the IAT sensor.

Time Since Engine Off: This parameter displays the amount of time (hours:minutes:seconds) that has elapsed since
the engine was last cycled OFF.

Total Fuel Trim (Bank 1 or Bank 2): This parameter displays the overall fuel trim from the idle/decel cell and the
cruise/accel cell.

Total Misfire: This parameter displays the total number of cylinder firing events that the control module detected as
misfires for the last 200 crankshaft revolution sample period.

TP Sensor 1 (Throttle Position): This parameter displays the actual voltage on the TP sensor 1 signal circuit as
measured by the ECM.

TP Sensor 1 Learned Lower Position (Throttle Position): This parameter displays the learned minimum value of TP
sensor 1 as recorded by the ECM during the last learn procedure.

TP Sensor 2 (Throttle Position): This parameter displays the actual voltage on the TP sensor 2 signal circuit as
measured by the ECM.

TP Sensor 2 Learned Lower Position (Throttle Position): This parameter displays the learned minimum value of TP
sensor 2 as recorded by the ECM during the last learn procedure.

TP Sensor 1-2 Correlation (Throttle Position): This parameter displays ‘Fault’ when the ECM detects that TP sensor 1
voltage signal is not within the correct relationship to TP sensor 2. Tech 2 displays ‘Okay’ under normal operating
conditions.

Transmission Gear: This parameter displays the position of the transmission gear selector that is transmitted over the
serial data circuit from the TCM.

Transmission Gear Selector Signal: This parameter displays the position of the transmission gear selector that is
transmitted over the serial data circuit from the TCM.

Vehicle Speed: This parameter displays the speed of the vehicle as calculated by the TCM from information received
from the vehicle speed sensor (VSS).

Volumetric Efficiency: This parameter displays the volumetric efficiency of the engine as calculated by the control
module.

8.5 OBD

Data

Typical Values

Tech 2 Display

Units Displayed

Ignition On

Engine Running

B1S1 O2 Sensor (Bank 1 Sensor 1)

mA

0.008

0

Engine Management – V6 – Diagnostics

Page 6C1-2–243

B1S1 Lambda Value (Bank 1 Sensor 1)

:1 (= Lambda)

1.000

1.003

B1S2 O2 Sensor (Bank 1 Sensor 2)

mV

440

445

B1S2 Short Term Fuel Trim (Bank 1 Sensor 2)

%

99.2%

99.2%

B2S1 O2 Sensor (Bank 2 Sensor 1)

mA

0.000

0.024

B2S1 Lambda Value (Bank 2 Sensor 1)

:1 (= Lambda)

1.003

0.995

B2S2 O2 Sensor (Bank 2 Sensor 2)

mV

440

475

B2S2 Short Term Fuel Trim (Bank 2 Sensor 2)

%

99.2

99.2

Fuel System 1 Automatic Control Loop

—

—

—

Fuel System 2 Automatic Control Loop

—

—

—

Calculated Load

%

100.0

18.8

Engine Coolant Temperature

°C

56 90

B1 Short Term Fuel Trim (Bank 1)

%

0.0

–0.8

B1 Long Term Fuel Trim (Bank 1)

%

0.0

0.0

B2 Short Term Fuel Trim (Bank 2)

%

0.0

0.8

B2 Long Term Fuel Trim (Bank 2)

%

0.0

0.0

Engine Speed

RPM

0

588

Vehicle

Speed

km/h 0 0

Ignition Timing Advance for Cylinder 1

°CA

0 13

Intake Air Temperature

°C

47 32

Mass Air Flow

g/s

0.00

2.75

Absolute TP (Throttle Position)

%

14.5

OBD Requirements to which Vehicle is Designed

EOBD

—

—

Distance While MIL is Activated

km

0

0

8.6 Actuator

Tests

Fuel Pump Relay Test

This test allows the Technician to turn the fuel pump on and off.

N O T E

To avoid the possibility of engine flooding and
subsequent catalytic converter damage, Tech 2
will deactivate the fuel pump relay after 2
seconds.

Precondition: Ignition ‘On’, engine ‘Off’.

Electronic Throttle Control Test

This selection from the Tech 2 Actuator Test menu, provides two parameters; the Calculated Throttle Position and the
Desired Throttle Position. As the Technician increases or decreases the throttle opening in 10% increments, each of the
two parameters should be the same.

Preconditions: Ignition ‘On’, engine ‘Off’, vehicle speed is 0 km/h, there are no vehicle speed DTCs set and the ECM is
not performing a throttle learn procedure.

A/C Relay Test

Allows the Technician to turn the air conditioning relay ‘On’ and ‘Off’.

Engine Management – V6 – Diagnostics

Page 6C1-2–244

Precondition: Ignition ‘On’.

Cooling Fan (PWM)

Take care that no-one can access the engine
compartment during these tests!

This test allows the Technician to turn the cooling fan on in increments to its maximum speed.

Precondition: Ignition ‘On’ Air conditioning is ‘Off’..

Alternator L Terminal

This test allows the Technician to turn ‘On’ and ‘Off’, the commanded state of the voltage regulator in the alternator. ‘On’
displays a commanded state of 99%, while ‘Off’ displays a commanded state of 0%.

Precondition: Engine running.

EVAP Purge Solenoid

This test allows the Technician to control the EVAP purge solenoid valve. The normal commanded state is ‘0%’. The
system will increase or decrease the amount of purge by changing the duty cycle of the purge valve in 10% increments
within a range of 0 – 100%. The system will remain in the commanded state until cancelled by Tech 2.

N O T E

The EVAP Purge Solenoid Command parameter
may not change states when using this output
control.

Precondition: Ignition ‘On’, engine ‘Off’.

Engine Speed Control

Other DTCs may set when the Engine Speed
Control function is used. Disregard those
DTCs that set under this condition.

Allows the increase / decrease of the engine speed in 20 – 30 rpm increments from the base idle speed, up to 1,600
rpm.

N O T E

If the engine coolant temperature is below the
prescribed minimum, a message to that effect is
displayed and access to engine speed control is
blocked.

Preconditions: Engine running, engine temperature above 80

°C, transmission in Park or Neutral.

Engine Management – V6 – Diagnostics

Page 6C1-2–245

Starter Motor Relay Test

The engine will crank and start during the
starter relay test.

Allows the Technician to turn the starter relay ‘On’, thereby activating the starter motor and cranking the engine.

Preconditions: Apply park brake, firmly apply foot brake, ignition ‘On’, engine ‘Off’, transmission in Park or Neutral.

Fuel Injector Balance

This test allows the Technician to check the fuel flow through each injector when the engine is not running. The
sequence of events are:

1

Install a fuel pressure gauge to the fuel rail.

2

Select ‘Fuel Injector Balance Test’, from the ‘Actuator Test’ menu on Tech 2

3

Activate the fuel injector balance test with Tech 2. This action activates the fuel pump and stabilises the fuel
delivery system fuel pressure. The fuel pump is then turned off.

4

Note the stabilised fuel rail pressure.

5

When the pump is turned ‘Off’, the injector is activated for a pre-determined time.

6

The fuel pressure drop is then noted from the fuel pressure gauge.

N O T E

For a detailed procedure and analysis of fuel
injector condition, refer to 5.3 Fuel Injector
Balance Test.

8.7 Programming

F0: ICU Link to ECM/PIM: Should the ECM, PIM or ICU be replaced, the modules must be security linked to

each other. If this linking procedure is not performed, the vehicle will not crank nor run. For additional
information relating to Tech 2 and the linking procedure, refer to 11A – Immobiliser.

N O T E

After an ECU reset, the ignition switch must be
turned Off for at least 10 seconds and then
turned On for at least one minute, before
attempting communication between Tech 2 and
the ECU.

Preconditions: TIS approval (TIS 2000 Security Access) must be obtained, the four digit security number
entered into Tech 2 and the theft deterrent system disarmed. Then the ignition must be turned ‘On’, using a
programmed remote coded key.

F1: Reset

ECU: This function erases the security link between the Engine Control Module (ECM) and the

Powertrain Interface Modules (PIM). If this procedure is performed, the engine will not crank nor run. A ICU
Link to ECM/PIM procedure will need to be performed. For additional information relating to the ICU Link to
ECM/PIM procedure, refer to 11A – Immobiliser.