Isuzu KB P190. Manual - part 594

6E–206

ENGINE DRIVEABILITY AND EMISSIONS

DIAGNOSTIC TROUBLE CODE (DTC) P0601 ECM MEMORY CHECKSUM

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

Circuit Description

The engine control module (ECM) used in this vehicle
utilizes an electrically erasable programmable read-only
memory (EEPROM). The EEPROM contains program
information and the calibrations required for engine,
transmission, and powertrain diagnostics operation.
Unlike the PROM used in past applications, the
EEPROM is not replaceable. When the ECM is
replaced or a calibration update is required, the ECM

must be programmed using a Tech 2.

Diagnostic Aids

• Diagnostic Trouble Code P0601 indicates that the

contents of the EEPROM have changed since the
ECM was programmed. The only possible repair is
ECM reprogramming or replacement. Check service
bulletins to program the replacement ECM with the
correct software and calibration for the vehicle.

Diagnostic Trouble Code (DTC) P0601 ECM Memory Checksum

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0601

ECM Memory Checksum

ECM memory area error.

Engine control disabled.

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 By Priority” in “F0:

Diagnostic Trouble Code”.

Is the DTC P0601 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

1. Using the Tech2, ignition “On” and engine “Off”.

2. Select “Clear DTC Information” with the Tech2 and

clear the DTC information.

3. Operate the vehicle and monitor the “F5: Failed

This Ignition” in “F2: DTC Information”.

Was the DTC P0601 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

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 immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.

—

Verify repair

—

ENGINE DRIVEABILITY AND EMISSIONS

6E–207

DIAGNOSTIC TROUBLE CODE (DTC) P0602 ECU PROGRAMMING ERROR

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

Circuit Description

replaced or a calibration update is required, the ECM
must be programmed using a Tech 2.

Diagnostic Aids

• Diagnostic Trouble Code P0602 indicates when non

programmed ECM is used without service
programming system (SPS). The replacement ECM
must be programmed.

Diagnostic Trouble Code (DTC) P0602 ECU Programming Error

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0602

ECU Programming Error

ECM memory area error.

Engine control disabled.

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 By Priority” in “F0:

Diagnostic Trouble Code”.

Is the DTC P0602 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

Download the latest software to the ECM using the
“SPS (Service Programming System)”.
Is the action complete?

—

Verify repair

—

6E–208

ENGINE DRIVEABILITY AND EMISSIONS

DTC P0650 MALFUNCTION INDICATOR LAMP (MIL) CONTOROL CIRCUIT

MALFUNCTION

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

Circuit Description

The check engine lamp should always be illuminated
and steady with ignition “ON” and the engine stopped.
Ignition feed voltage is supplied directly to the check
engine lamp indicator. The Engine Control Module
(ECM) turns the check engine lamp “ON” by grounding
the check engine lamp driver circuit. The check engine
lamp should not remain “ON” with the engine running
and no DTC(s) set. A steady check engine lamp with
the engine running and no DTC(s) suggests a short to
ground in the check engine lamp driver circuit.

Diagnostic Aids

An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

• Poor connection or damaged harness - Inspect the

ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0650

Malfunction Indicator Lamp (MIL) Con-
trol Circuit Malfunction

Check engine lamp circuit open, short to
ground or short to voltage circuit.

No fail-safe function.

ENGINE DRIVEABILITY AND EMISSIONS

6E–209

Diagnostic Trouble Code (DTC) P0650

Malfunction Indicator Lamp (MIL) Control Circuit 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 By Priority” in “F0:

Diagnostic Trouble Code”.

Is the DTC P0650 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

1. Using the Tech2, ignition “On” and engine “Off”.

2. Select “Clear DTC Information” with the Tech2 and

clear the DTC information.

3. Operate the vehicle and monitor the “F5: Failed

This Ignition” in “F2: DTC Information”.

Was the DTC P0650 stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

1. Ignition “On”, engine “Off”.

2. Check the “Check Engine” lamp.

Does the lamp turn “On”?

—

Go to Step 5

Go to Step 6

1. Ignition “On”, engine “Off”.

2. Check the “Check Engine” lamp.

Does the lamp turn “Off”?

—

Go to Step 9

Go to Step 7

Check the “Check Engine” lamp bulb.
If the bulb is burnt out, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 7

Check for poor/faulty connection at the meter
connector and ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 8

C-56(J2)

B-24

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