Isuzu KB P190. Manual - part 312

6E-214 Engine Control System (4JH1)

Step Action

Value(s)

Yes

1.  Turn OFF the ignition.
2.  Disconnect the neutral switch harness connector.
3.  Turn ON the ignition, with the engine OFF.
4.  Observe the Neutral Switch parameter with the

scan tool while momentarily jumping across the
neutral switch harness connectors between pin 1
of E-11 connector and pin 1 of E-12 connector.

Does the scan tool indicate ON when the circuit is
jumped and OFF when the circuit is not jumped?



Go to Step 9

Go to Step 6

1. Connect a test lamp between the ignition voltage

feed circuit of the neutral switch harness (pin 1 of
E-12 connector) and a known good ground.

2. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?



Go to Step 8

Go to Step 7

Repair the open circuit or high resistance on the
ignition voltage feed circuit between the ECM (10A)
fuse (EB-4) and the neutral switch (pin 1 of E-12
connector).
Did you complete the repair?



Go to Step 13



1. Test the neutral switch signal circuit between the

engine control module (ECM) (pin 87 of C-57
connector) and the neutral switch (pin 1 of E-11
connector) for an open circuit or high resistance.

2. Repair the circuit(s) as necessary.
Did you find and correct the condition?



Go to Step 13

Go to Step 10

1. Turn OFF the ignition.
2. Inspect for an intermittent and for poor

connections at the harness connectors of the
neutral switch (pin 1 of E-11 connector and pin 1
of E-12 connector).

3. Repair the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 13

Go to Step 11

1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor

connection on the neutral switch circuit at the
harness connector of the ECM (pin 87 of C-57
connector).

4. Repair the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 13

Go to Step 12

Replace the neutral switch. Refer to Neutral Switch
Replacement in Transmission Section.
Did you complete the replacement?



Go to Step 13



Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?



Go to Step 13



Engine Control System (4JH1) 6E-215

Step Action

Value(s)

Yes

1. Reconnect all previously disconnected harness

connector(s).

2. Clear the DTCs with the scan tool.
Important: Following conditions must be met two
consecutive driving cycles before clear with the scan
tool. (One driving cycle: Ignition switch ON > Engine
run > Ignition switch OFF for 10 seconds)

• The engine speed is higher than 665 RPM
• The vehicle speed is lower than 2 km/h (1.2

MPH)

• The clutch pedal is released after once

depressed

• Neutral

position

3. Turn ON the ignition, with the engine OFF.
4. Observe the Neutral Switch parameter with the

scan tool while shift to neutral and other
positions.

Does the scan tool indicate ON when the position is
neutral and OFF when other than the neutral?



Go to Step 14

Go to Step 3

Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?



Go to Diagnostic

Trouble Code (DTC)

List System

6E-216 Engine Control System (4JH1)

DTC P1605 (Symptom Code C, D, E) (Flash Code 55)

Circuit Description
This diagnostic applies to internal microprocessor
integrity conditions within the engine control module
(ECM). The electronically erasable programmable read
only memory (EEPROM) memorize some data for
engine control and communication with other control
module. If the ECM detects memory area malfunction
inside of the ECM, this DTC will set.
Condition for Setting the DTC

• The ECM detects internal seed or key file in

EEPROM data is destroyed (Symptom Code C).

• The ECM detects reading or writing from the

EEPROM data is failed during initialization
(Symptom Code D).

• The ECM detects total sum of EEPROM data is

not equal to registered value during initialization
(Symptom Code E).

Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicator

lamp (MIL) when the diagnostic runs and fails.

• The ECM uses default EPROM data substitution of

faulty EEPROM. (Symptom Code D & E).

Condition for Clearing the MIL/DTC

• The ECM turns OFF the MIL when the diagnostic

runs and does not fail.

• A history DTC clears after 40 consecutive driving

cycles without a fault. Or clear with the scan tool.

DTC P1605 (Symptom Code C, D, E) (Flash Code 55)

Step Action

Value(s)

Yes

Did you perform the Diagnostic System Check-
Engine Controls?



Go to Step 2

Go to Diagnostic

System Check-

Engine Controls

1.  Install the scan tool.
2.  Turn OFF the ignition for 30 seconds.
3.  Turn ON the ignition, with the engine OFF.
4. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does the DTC fail this ignition?



Go to Step 3

Go to Step 4

Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?



Go to Step 4



1.  Clear the DTCs with the scan tool.
2.  Turn OFF the ignition for 30 seconds.
3.  Turn ON the ignition, with the engine OFF.
4.  Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition?



Go to Step 3

Go to Step 5

Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?



Go to Diagnostic

Trouble Code (DTC)

List System

Engine Control System (4JH1) 6E-217

DTC P1610 (Symptom Code A) (Flash Code 56)

Circuit Description
The electronically erasable programmable read only
memory (EEPROM) memorize immobilizer security
code and secret key for communication with the
immobilizer control unit (ICU). If the engine control
module (ECM) detects immobilizer functions are not
programmed into the ECM, this DTC will set.
Condition for Setting the DTC

• The ECM detects immobilizer security code and

secret key is not programmed.

Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicator

lamp (MIL) when the diagnostic runs and fails.

• The desired fuel injection quantity is set 0 mg/strk.

Condition for Clearing the MIL/DTC

• The ECM turns OFF the MIL when the diagnostic

runs and does not fail.

• A history DTC clears after 40 consecutive driving

cycles without a fault. Or clear with the scan tool.

Diagnostic Aids

• Non programmed ECM may set this DTC.
• ECM with wrong specification may set this DTC.

DTC P1610 (Symptom Code A) (Flash Code 56)

Step Action

Value(s)

Yes

Did you perform the Diagnostic System Check-
Engine Controls?



Go to Step 2

Go to Diagnostic

System Check-

Engine Controls

1.  Install the scan tool.
2.  Turn OFF the ignition for 30 seconds.
3.  Turn ON the ignition, with the engine OFF.
4. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does the DTC fail this ignition?



Go to Step 3

Go to Diagnostic

Aids

Program or reprogram immobilizer function into the
engine control module (ECM). Refer to Programming
Engine Control Module (ECM) in immobilizer section.
Did you find and correct the condition?



Go to Step 5

Go to Step 4

Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?



Go to Step 5



Go to Step 3

Go to Step 6

Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?



Go to Diagnostic

Trouble Code (DTC)

List System

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