Isuzu 4JA1 Workshop Manual page 342

6E-88 Engine Control System (4JH1)
Step
4 1. Turn OFF the ignition.
2. Connect a DMM between the ESO solenoid valve
control signal circuit (pin 5 of E-6 connector) and
a known good ground.
3. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value?
5 1. Test the ESO solenoid valve control signal circuit
between the ECM (pin 29 of C-57 connector) and
the PCU (pin 5 of E-6 connector) for a short to
ground.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
6 1. Test the ESO solenoid valve control signal circuit
between the ECM (pin 29 of C-57 connector) and
the PCU (pin 5 of E-6 connector) for an open
circuit or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
7 1. Turn OFF the ignition.
2. Inspect for an intermittent, for a poor connection
and corrosion on the ESO solenoid valve control
signal circuit at the harness connector of the
PCU (pin 5 of E-6 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition?
8 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor
connection on the ESO solenoid valve control
signal circuit at the harness connector of the
ECM (pin 29 of C-57 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
9 Important: The fuel injection pump must be timed to
the engine.
Replace the fuel injection pump. Refer to Fuel
Injection Pump Replacement in engine mechanical
section.
Did you complete the replacement?
10 Important: Replacement
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?
11 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Monitor the DTC Information with the scan tool.
6. Turn OFF the engine.
Does the DTC fail this ignition before the ECM turns
OFF?
12 Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?
Action
ECM must
Value(s)
10 volts
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be
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Go to Diagnostic
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Trouble Code (DTC)
Yes
Go to Step 7 Go to Step 6
Go to Step 11 Go to Step 10
Go to Step 11 Go to Step 8
Go to Step 11 Go to Step 9
Go to Step 11 Go to Step 10
Go to Step 11
Go to Step 11
Go to Step 3 Go to Step 12
List System OK
No
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