Isuzu 4JA1 Workshop Manual page 414

6E-160 Engine Control System (4JH1)
DTC P0561 (Symptom Code B) (Flash Code 18)
Circuit Description
The engine control module (ECM) main relay is
energized when the ECM receives an ignition voltage
switch ON signal. When the ignition switch is OFF, the
ECM main relay is de-energized after a certain length of
time passed. If the ECM detects the ignition voltage
switch signal is changed to OFF during the ECM is
energized, this DTC will set.
Condition for Setting the DTC
• The ECM detects internal ignition voltage feed
circuit is failed after initialization.
Action Taken When the DTC Sets
• The ECM does not illuminate the malfunction
indicator lamp (MIL) when the diagnostic runs and
fails.
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. Monitor the Diagnostic Trouble Code (DTC)
Information with the scan tool.
Does the DTC fail this ignition?
3 Important: Replacement
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?
4 1. Clear the DTCs with the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition?
5 Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?
Action
ECM must
• The ECM turns OFF the ECM.
Condition for Clearing the DTC
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
DTC P0561 (Symptom Code B) (Flash Code 18)
Value(s)


be



Trouble Code (DTC)
Yes
Go to Diagnostic
System Check-
Go to Step 2 Engine Controls
Go to Step 3 Go to Step 4
Go to Step 4
Go to Step 3 Go to Step 5
Go to Diagnostic
List
No

System OK