Isuzu KB P190. Manual — part 843

Engine Management – V6 – Diagnostics

Page 6C1-2–94

9

1

The HO2S is detecting a rich or lean exhaust
condition or may be contaminated. Inspect for
one of the following conditions:

•

HO2S connector water intrusion.

•

A silicon-contaminated HO2S.

•

Fuel-contaminated engine oil – refer to 6.5

Alcohol / Contaminants in Fuel

Diagnosis.

•

Rich fuel injectors.

•

Lean fuel injectors. Refer to 6C Fuel
System – V6

•

An exhaust leak between the HO2S and
the engine. Refer to 6F Exhaust System –
V6.

•

Vacuum leaks.

•

Fuel contamination. Water, even in small
amounts, can be delivered to the fuel
injectors, causing a lean exhaust to be
indicated. Excessive alcohol in the fuel can
also cause this condition. Refer to 6.5

Alcohol / Contaminants in Fuel

Diagnosis in this Section.

•

An inaccurate mass air flow (MAF) sensor.

2

Repair any of the above or similar engine
conditions, as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 10

10

1

Test for intermittent and poor connections at the
HO2S. Refer to 8A Electrical-Body and Chassis.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 13

11

1

Test for intermittent and poor connections at the
engine control module (ECM). Refer to 6C1-3
Engine Management – V6 – Service Operations.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 14

12

1

Repair the circuit with high resistance. Refer to
8A Electrical-Body and Chassis.

Did you complete the repair?

—

Go to Step 15

—

13

1

Replace the affected HO2S. Refer to 6C1-3
Engine Management – V6 – Service Operations.

Did you complete the replacement?

—

Go to Step 15

—

14

1

Replace the ECM. Refer to 6C1-3 Engine
Management – V6 – Service Operations.

Did you complete the replacement?

—

Go to Step 15

—

15

1

Use Tech 2 to clear the DTCs.

2

Turn OFF the ignition for 30 seconds.

3

Start the engine.

4

Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame / Failure Records.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 16

Engine Management – V6 – Diagnostics

Page 6C1-2–95

16

1

Using Tech 2, select the DTC display function.

Does Tech 2 display any DTCs?

—

Go to the

appropriate DTC

Table in this

Section

System OK

When all diagnosis and repairs are completed, clear all DTCs and verify correct operation

7.13 DTC P0196, P0197 or P0198

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•

DTC P0196 – Engine Oil Temperature Sensor Range / Performance

•

DTC P0197 – Engine Oil Temperature Voltage Low

•

DTC P0198 – Engine Oil Temperature Voltage High

Circuit Description

The ECM applies a positive 5 V reference voltage to the engine oil temperature (EOT) sensor through the 5 V reference
circuit and the ground through the low reference circuit.

The EOT sensor is a variable resistor that measures the temperature of the engine oil. This sensor provides signal
voltage to the ECM that is proportional to the oil temperature off the engine.

The ECM monitors and compares the EOT sensor signal voltage against a specified range. An EOT sensor circuit DTC
sets if the ECM detects the EOT sensor signal voltage is outside the specified range.

Conditions for Running the DTC

DTC P0196, P0197 and P0198 run continuously when the engine is running.

Conditions for Setting the DTC

DTC P0196

The ECM detects the engine oil temperature sensor is not within 100

°C of the modelled temperature

N O T E

The modelled temperature is the temperature
that the ECM expects to see given current engine
operating conditions.

DTC P0197

The ECM detects the engine oil temperature is less than -35

°C for longer than 3 seconds.

DTC P0198

The ECM detects the engine oil temperature is greater than 170

°C for longer than 3 seconds.

Conditions for Clearing DTC

The EOT sensor circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type C DTC sets and conditions for clearing Type C DTCs.

Additional Information

•

Refer to 6C1-1 Engine Management – V6 – General Information for details of the EOT sensor operation.

•

For an intermittent fault condition, refer to 5.2

Intermittent Fault Conditions in this Section.

Engine Management – V6 – Diagnostics

Page 6C1-2–96

•

Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.

•

To assist diagnosis, refer to 3

Wiring Diagrams and Connector Charts in this Section, for the system wiring

diagram and connector charts.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

5

Test signal circuit of the EOT sensor. This circuit should display a voltage within the specified range.

6

Measures the integrity of the EOT sensor low reference circuit. Removal of the Fuse 29 enables the ECM to power
down completely prior to the test procedure.

DTC P0196, P0197 or P0198 Diagnostic Table

Step Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

4.4 Diagnostic

System Check in

this Section

2

Test the engine cooling system for correct operation. Refer to 6B1
Engine Cooling – V6.

Was any fault found and rectified?

Go to Step 11

Go to Step 3

3

Inspect the engine oil condition. Refer to 6A1 Engine Mechanical –
V6.

Was any fault found and rectified?

Go to Step 11

Go to Step 4

4

1

Switch off the ignition for 30 seconds.

2

Operate the vehicle within the conditions for running the DTC.

3

Using Tech 2, select the DTC display function.

Does DTC P0196, P0197 or P0198 fail this ignition cycle?

Go to Step 5

Refer to Additional

Information in this

DTC

5

1

Switch off the ignition.

2

Disconnect the EOT sensor wiring connector.

3

Switch on the ignition with the engine not running.

4

Using a digital multimeter, measure the voltage between the
EOT sensor signal circuit and the ECM housing.

Does the multimeter display 4.8 – 5.2 V?

Go to Step 6

Go to Step 7

6

1

Switch off the ignition.

2

Remove ECM / TCM Fuse 29 from the engine compartment
fuse and relay panel assembly.

3

Using a digital multimeter, measure the resistance between the
EOT sensor low reference circuit and the ECM housing.

N O T E

Install the ECM Fuse 29 to the engine compartment fuse
and relay panel assembly after completing this test.

Does the multimeter display 5

Ω?

Go to Step 9

Go to Step 8

7

Test EOT sensor signal circuit for a high resistance, open circuit,
short to ground or short to voltage fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 10

Engine Management – V6 – Diagnostics

Page 6C1-2–97

Step Action

Yes

No

8

Test the EOT sensor low reference circuit for a high resistance and
open circuit fault condition. Refer to 8A Electrical - Body and Chassis
for information on electrical fault diagnosis.

N O T E

The EOT sensor shares the low reference circuit with
other sensors. A fault condition in the low reference circuit
may trigger DTCs on sensors that share this circuit. Refer
to

3 Wiring Diagrams and Connector Charts in this

Section, to assist diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 10

9

Replace the EOT sensor. Refer to 6C1-3 Engine Management – V6 –
Service Operations.

Was the repair completed?

Go to Step 11

—

10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –

Service Operations.

Was the repair completed?

Go to Step 11

—

11 1

Using Tech 2, clear the DTCs.

2

Switch off the ignition for 30 seconds.

3

Start the engine.

4

Operate the vehicle within the conditions for running the DTC.

Does any of the conditions for the engine oil pressure sensor circuit
DTCs fail this ignition cycle?

Go to Step 2

Go to Step 12

12 Using Tech 2, select the DTC display function.

Does Tech 2 display any DTCs?

Go to the

appropriate DTC

Table in this Section

System OK

When all diagnosis and repairs are completed, check the system for correct operation.

7.14 DTC P0201, P0202, P0203, P0204, P0205,

P0206, P0261, P0262, P0264, P0265,
P0267, P0268, P0270, P0271, P0273,
P0274, P0276 or P0277

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•

DTC P0201 – Injector 1 Control Circuit Malfunction

•

DTC P0202 – Injector 2 Control Circuit Malfunction

•

DTC P0203 – Injector 3 Control Circuit Malfunction

•

DTC P0204 – Injector 4 Control Circuit Malfunction

•

DTC P0205 – Injector 5 Control Circuit Malfunction

•

DTC P0206 – Injector 6 Control Circuit Malfunction

•

DTC P0261 – Injector 1 Control Circuit Low Voltage

•

DTC P0262 – Injector 1 Control Circuit High Voltage

•

DTC P0264 – Injector 2 Control Circuit Low Voltage

•

DTC P0265 – Injector 2 Control Circuit High Voltage

•

DTC P0267 – Injector 3 Control Circuit Low Voltage