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Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 65

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–255

DIAGNOSTIC TROUBLE CODE (DTC) P1173 (SYMPTOM CODE 3)

(FLASH CODE 22) FUEL REDUCTION CAUSED BY HIGH COOLANT

TEMPERATURE

DIAGNOSTIC TROUBLE CODE (DTC) P1173 (SYMPTOM CODE 7)

(FLASH CODE 22) FUEL REDUCTION CAUSED BY HIGH FUEL TEMPERATURE

DIAGNOSTIC TROUBLE CODE (DTC) P1173 (SYMPTOM CODE A)

(FLASH CODE 22) FUEL REDUCTION CAUSED BY LOW TEMPERATURE

Condition for setting the DTC and action taken when the DTC sets

Circuit Description

The engine coolant temperature (ECT) sensor is
installed on the coolant stream. High coolant
temperature produces a low resistance. The ECM
supplies 5 volts signal to the ECT sensor through
resisters in the ECM and measures the voltage. The
signal voltage will be low when the engine temperature
is hot.
The fuel temperature sensor is assembled inside of the
pump control unit (PSG). The signal of fuel temperature
is sent via the CAN-bus from the PSG to ECM.
If the engine coolant temperature is excessively high
condition, DTC P1173 (Symptom Code 3) will be stored.
If the fuel temperature is excessively high or low
condition, DTC P1173 (Symptom Code 7) or P1173
(Symptom Code A) will be stored.

Diagnostic Aids

An intermittent may be caused by the following:

• Poor connections.

• Misrouted harness.

• Rubbed through wire insulation.

• Broken wire inside the insulation.
Check for the following conditions:

• Poor connection at ECM and PSG-Inspect harness

connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.

• Damaged harness-Inspect the wiring harness for

damage. If the harness appears to be OK, observe
the “Coolant Temperature” or “Fuel Temperature”
display on the Tech2 while moving connectors and
wiring harness related to the sensor.

Diagnostic Trouble Code (DTC) P1173 (Symptom Code 3) (Flash Code 22) Fuel

Reduction Caused By High Coolant Temperature

Flash

Code

Symptom

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P1173

OFF

Fuel Reduction Caused By
High Coolant Temperature

Excessive high engine cool-
ant temperature is detected.

No fail-safe function.

OFF

Fuel Reduction Caused By
High Fuel Temperature

Fuel temperature is more than
100°C.

PSG (pump control unit) con-
trols fuel injection quantity
based on engine speed and
fuel temperature.

OFF

Fuel Reduction Caused By
Low Fuel Temperature

Excessive low fuel tempera-
ture is detected.

No fail-safe function.

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”.

Is the DTC P1173 (Symptom Code 3) stored as
“Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

6E–256

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Select “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.

Was the DTC P1173 (Symptom Code 3) stored in this
ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

Check the engine overheat condition.
Was the problem found?

—

Repair the

cause of

overheat and

verify repair

Go to Step 5

1. Using the Tech 2, ignition “On” and engine “On”.

2. Monitor the “Coolant Temperature” in the data

display.

Does the Tech 2 indicate correct “Coolant
Temperature” depending on warm up time?

—

Go to Step 9

Go to Step 6

Using the DVM and check the ECT sensor.

1. Ignition “Off”, engine “Off”.

2. Disconnect ECT sensor connector.

3. Measure the resistance of ECT sensor.

Does the tester indicate standard resistance as shown
in the following table?

Standard

resistance

Go to Step 9

Go to Step 7

Substitute a known good ECT sensor assembly and
recheck.
Was the problem solved?

—

Go to Step 8

Go to Step 9

Replace the ECT sensor.
Is the action complete?

—

Verify repair

—

Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?

—

Verify repair

Go to Step 10

Step

Action

Value(s)

Yes

Temperature (°C)

Resistance (

Ω) (Approximately)

-30

27500

-20

16100

5760

2370

1080

537

290

100

161

120

ECT Sensor

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–257

Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

Step

Action

Value(s)

Yes

6E–258

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1173 (Symptom Code 7) (Flash Code 22) Fuel

Reduction Caused By High Fuel Temperature

Diagnostic Trouble Code (DTC) P1173 (Symptom Code A) (Flash Code 22) Fuel

Reduction Caused By Low Temperature

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”.

Is the DTC P1173 (Symptom Code 7) or P1173
(Symptom Code A) stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Select “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.

Was the DTC P1173 (Symptom Code 7) or P1173
(Symptom Code A) stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?

—

Verify repair

Go to Step 5

Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Go to Step 6

Go to Step 7

—

Verify repair

—

Replace the injection pump assembly.
Is the action complete?

—

Verify repair

—

Content .. 63 64 65 66 ..