Isuzu KB P190. Manual — part 599

6E–226

ENGINE DRIVEABILITY AND EMISSIONS

DIAGNOSTIC TROUBLE CODE (DTC) P1649

IMMOBILIZER FUNCTION NOT PROGRAMMED

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

Circuit Description

The ECM decides whether that is an abnomality in the
immobilizer control system. DTC P1649 is recorded by
the ECM when security code & secret key not
programmed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at ECM and Immobilizer-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, disconnect
the ECM and Immobilizer, turn the ignition “ON” and
observe a voltmeter connected to the suspect driver
circuit at the ECM and Immobilizer harnass connector
while moving connectors and wiring harnesses
relates to the MIL. A change in voltage will indicate
the location of the fault.

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P1649

-

Immobilizer Function Not Programmed Immobilizer function is not programmed in the

ECM.

1. Engine does not start.
2. Check engine lamp flash.

ENGINE DRIVEABILITY AND EMISSIONS

6E–227

Diagnostic Trouble Code (DTC) P1649 Immobilizer Function Not Programmed

Step

Action

Value(s)

Yes

No

1

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

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

2

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 P1649 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

3

3

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 P1649 stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

4

4

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

2. Select “Immobilizer” in the system selection menu

“Body”.

3. Select “Read DTC Info Ordered By Priority” in the

“Diagnositic Trouble Code”.

Were the any DTC's B0002 or B0009 stored in this
ignition cycle?

—

Refer to

“Immobilizer

Workshop

Manual” & Go

to DTC Chart

B0002 or

B0009

Go to Step 5

5

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 6

6

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

—

6E–228

ENGINE DRIVEABILITY AND EMISSIONS

DIAGNOSTIC TROUBLE CODE (DTC) P1693

TACHOMETER OUTPUT LOW VOLTAGE

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

Circuit Description

Based on the information from the Crank Position
Sensor (CKP), X58 reference signal is generated at
each rotation of the crankshaft.
Engine Control Module (ECM) converts X58 reference
signal into the square wave signal which is used to drive
the pulse generator of the tachometer.
When the wave length of the output signal is long, the
tacho meter indicates the engine speed is low, and vise
versa.
This malfunction detects a low impedance short to

ground or open contact on the Tacho output, the
Diagnostic Trouble Code P1693 will be set.

Diagnostic Aids

• Poor connections or a damaged harness - Inspect

the harness connections for: backed out terminals,
imprope, mating or damaged terminals. Also check
for open circuit, short to ground, and short to voltage.

• This malfunction detects a low impedance short to

ground or open contact on the ECM out put circuit.

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P1693

B

Tachometer Output Low Voltage

Tacho output circuit short to ground circuit.

No fail-safe function.

ENGINE DRIVEABILITY AND EMISSIONS

6E–229

Diagnostic Trouble Code (DTC) P1693 Tachometer Output Low Voltage

Step

Action

Value(s)

Yes

No

1

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

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

2

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 P1693 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

3

3

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 P1693 stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

4

4

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

—

Verify repair

Go to Step 5

5

If a oscilloscope is available, monitor the Tachometer
output signal. Does the oscilloscope indicate correct
wave form?

—

Go to Step 10

Not available:

Go to Step 6
Fixed at low:
Go to Step 6

Fixed at High:

Go to Step 7

25

C-56(J2)

B-24

11

Crankshaft Position (CKP) Sensor & Tacho Output Signal

Reference Wave Form





CH1
0V





CH2
0V




Measurement Terminal: CH1: J1-21(+) / CH2: J2-25(+) GND(-)
Measurement Scale: CH1: 2V/div / CH2: 10V/div 5ms/div

Measurement Condition: Approximately 2000rpm