Isuzu 4JA1 Workshop Manual page 461

DTC P1613 (Symptom Code A) (Flash Code 56)
Circuit Description
The engine control module (ECM) communicates with
the immobilizer control unit (ICU) to execute immobilizer
function. The ECM sends request signal to the ICU. The
ECM receives response signal from the ICU. Both
communication signals are carried out through the
Keyword 2000 serial data link. If the ECM does not
detect response signal from the ICU, this DTC will set.
Condition for Setting the DTC
• The ECM does not receive the immobilizer
response signal from the ICU.
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.
Step
1 Did you perform the Diagnostic System Check-
Engine Controls?
2 1. Install the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Select the "Immobilizer" in the system selection
menu.
5. Monitor the Diagnostic Trouble Code (DTC) Info
Ordered By Priority with the scan tool.
Does the immobilizer DTCs fail this ignition which
begin with B?
3 Monitor the DTC Information with the scan tool.
Does the DTC fail this ignition?
4 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?
5 Important: Replacement
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?
6 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?
7 Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?
Action
ECM must
Engine Control System (4JH1) 6E-207
Diagnostic Aids
• Non programmed ECM may set this DTC.
• Transponder key problem may set this DTC.
• Antenna coil problem may set this DTC.
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice:
• Keyword 2000 serial data link circuit problem may
cause this DTC set. The scan tool will not
communicate. Refer to scan tool Does Not
Communicate with Keyword 2000 Device in this
section.
• ECM with wrong specification may set this DTC.
DTC P1613 (Symptom Code A) (Flash Code 56)
Value(s)


DTC in Immobilizer


be



Trouble Code (DTC)
Yes
Go to Diagnostic
System Check-
Go to Step 2 Engine Controls
Go to Applicable
Section Go to Step 3
Go to Diagnostic
Go to Step 4
Go to Step 6 Go to Step 5
Go to Step 6
Go to Step 2 Go to Step 7
Go to Diagnostic
List
No
Aids

System OK