Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 55

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

6E–215

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–216

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

Diagnostic Trouble Code (DTC) P0606 (Symptom Code B) (Flash Code 28) ECU

Malfunction

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 P0606 (Symptom Code B) 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 P0606 (Symptom Code B) 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

—

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

6E–217

DIAGNOSTIC TROUBLE CODE (DTC) P0645 (SYMPTOM CODE 4)

(FLASH CODE 46) A/C COMPRESSOR RELAY CIRCUIT VOLTAGE LOW

DIAGNOSTIC TROUBLE CODE (DTC) P0645 (SYMPTOM CODE 8)

(FLASH CODE 46) A/C COMPRESSOR RELAY CIRCUIT VOLTAGE HIGH

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

Circuit Description

The voltage on the coil of the A/C compressor is
supplied by the ECM main relay. The ECM switches A/C
compressor relay to operate A/C compressor depends

on the A/C request signal and certain setting conditions.

Flash

Code

Symptom

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0645

A/C Compressor Relay Circuit
Voltage Low

A/C compressor relay circuit
open or short to ground cir-
cuit.

No fail-safe function.

A/C Compressor Relay Circuit
Voltage High

A/C compressor relay circuit
short to voltage circuit.

Resister

A/C
Compressor

ECM
Main Relay

Battery
Voltage

Glow
80A

Glow
Relay

Glow
Plug

0.5
BLU/
RED

0.5
BLK/
BLU
94

0.5
BRN/
RED

0.5
BLK

0.5
GRN

5.0
RED/
WHT

0.5
BLU/
RED

0.5
GRY

0.5
GRN

0.5
BRN

0.5
GRY/
YEL

A/C
10A

Heater
Relay

Blower
20A

A/C
Compressor
Relay

A/C
Thermo
Relay

Pressure
SW

5.0
BLK/
RED

Electronic
Thermostat

µP

Batt

µP

Batt

Engine
Control
Module
(ECM)

6E–218

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

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-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 DTC P0645 display on the Tech2 while moving
connectors and wiring harnesses.

Diagnostic Trouble Code (DTC) P0645 (Symptom Code 4) (Flash Code 46) A/C

Compressor Relay Circuit Voltage Low

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 P0645 (Symptom Code 4) 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 P0645 (Symptom Code 4) stored in this
ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

Check for poor/faulty connection at the A/C
compressor relay or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 5

C-56

X-5

4JA1-TC

X-10

4JH1-TC

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