Isuzu KB P190. Manual - part 431

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-107

Circuit/ System Testing DTC P0113

4

1.

Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
for the following conditions:

• A short to ground

• A short to the low reference circuit

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 8

Go to Step 6

5

Replace the MAF sensor. Refer to MAF Sensor
Replacement. (IAT sensor is internal to MAF
sensor)

Did you complete the replacement?

—

Go to Step 8

—

6

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect connections at the harness connector
of the ECM (pins 41 and 61 of E-90) for
corrosion.

4.

Repair or clean the connection(s) as
necessary.

Did you find and correct the condition?

—

Go to Step 8

Go to Step 7

7

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 8

—

8

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.

5.

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 9

9

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

1.

Install a scan tool.

2.

Turn OFF the ignition for 30 seconds.

3.

Turn ON the ignition, with the engine OFF.

4.

Observe the Intake Air Temperature (IAT)
Sensor parameter with a scan tool.

Is the IAT Sensor parameter more than the
specified value?

4.7 volts

Go to Step 3

Go to Diagnostic 

Aids

6E-108   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

3

1.

Turn OFF the ignition.

2.

Disconnect the mass air flow/ intake air
temperature (MAF/ IAT) sensor harness
connector.

3.

Connect a DMM between the signal circuit
(pin 4 of E-47) and a known good ground.

4.

Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

5.3 volts

Go to Step 4

Go to Step 5

4

Important: The IAT sensor may be damaged if the
sensor signal circuit is shorted to a voltage source.

1.

Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
for a short to battery or ignition voltage.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 13

5

Connect a 3-amp fused jumper wire between the
signal circuit and the low reference circuit (pins 4
and 5 of E-47).

Is the IAT Sensor parameter less than the specified
value?

0.1 volts

Go to Step 9

Go to Step 6

6

Connect a 3-amp fused jumper wire between the
signal circuit (pin 4 of E-47) and a known good
ground.

Is the IAT Sensor parameter less than the specified
value?

0.1 volts

Go to Step 8

Go to Step 7

7

1.

Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
for an open circuit or high resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 11

8

1.

Test the low reference circuit between the
ECM (pin 61 of E-90) and the IAT sensor (pin
5 of E-47) for an open circuit or high
resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 11

9

1.

Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
for a short to any 5 volts reference circuit.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 10

10

1.

Inspect for an intermittent and for poor
connections at the harness connector of the
IAT sensor (pins 4 and 5 of E-47).

2.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 12

Step

Action

Value(s)

Yes

No

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-109

11

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector of the
ECM (pins 41 and 61 of E-90).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 13

12

Replace the MAF sensor. Refer to MAF Sensor
Replacement. (IAT sensor is internal to MAF
sensor)

Did you complete the replacement?

—

Go to Step 14

—

13

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 14

—

14

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.

5.

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 15

15

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

6E-110   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC P0116 (Flash Code 23)

Circuit Description

The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor and it measures the temperature of
the engine coolant. If the ECM detects that the
difference of engine coolant temperature is smaller
than the calculated range during the predetermined
conditions, this DTC will set. This DTC will only run
once per ignition cycle within the enabling condition.

Condition for Running the DTC

• DTCs P0117, P0118, P0201 - P0204, P0500,

P0501 P124B, P1261, P1262 and P2146 - P2151
are not set.

• The ignition switch is ON.

• The engine coolant temperature is between -10 to

110

°C (14 to 230°F).

• The vehicle run time is longer than 18 minutes.

• The engine run time is longer than 5 minutes with

engine speed is more than 1200 RPM.

• The accumulation fuel injection quantity since

engine start is more than a threshold.

Condition for Setting the DTC

• The ECM detects that the difference of maximum

and minimum engine coolant temperature is less
than 5

°C (9°F).

Action Taken When the DTC Sets

• 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.

• The ECM limits fuel injection quantity.

• The ECM inhibits EGR control.

• The ECM inhibits cruise control.

Condition for Clearing the DTC

• Refer to DTC Type Definitions for Condition for

Clearing the MIL/ DTC - Type A.

Diagnostic Aids

• After starting the engine the ECT should rise

steadily to about 80 to 85

°C (176 to 185°F) then

stabilize when the thermostat opens.

• Use the Temperature vs. Resistance table to test

the ECT sensor at various temperature levels to
evaluate the possibility of a skewed sensor. A
skewed sensor could result in poor driveability
concerns.

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views

Circuit/ System Testing DTC P0116

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.

Test the engine cooling system for the
following condition. Refer to diagnosis of the
engine cooling system section for testing.

• Engine coolant level

• Engine coolant leakage

2.

Repair or replace as necessary

Did you find and correct the condition?

—

Go to Step 6

Go to Step 3

3

1.

Turn OFF the ignition

2.

Disconnect the engine coolant temperature
(ECT) sensor harness connector.

3.

Inspect for an intermittent, for poor connectors
and corrosion at the harness connector of the
ECT sensor (pins 1 and 2 of E-41).

4.

Disconnect the ECM harness connector.

5.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the ECM (pins 26 and 27 of E-
90).

6.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 6

Go to Step 4