Isuzu 4HL1 Workshop Manual page 213

Step
Check the circuit ground common or common
power circuit harness to ITP sensor, EGR
position sensor and common rail pressure
sensors for open wiring or short.
1. Starter switch "OFF".
2. Disconnect the ECM.
3. Disconnect the common rail pressure
sensor connector.
7
4. Jumper the common rail pressure sensor
connector
resistance at the ECM connector.
Was the resistance within range?
Repair or replace the faulty harness.
8
Is the action complete?
Review the DTC.
1. Certainly
pressure sensor and ECM connectors.
9
2. Using Tech 2, clear the DTC.
3. Perform test run and review the DTC.
Is DTC245 detected?
Check the common rail pressure sensor
output voltage.
1. Install Tech 2.
2. Starter switch "ON", and display the
engine data.
3. Observe the "Common Rail Pressure
10
Sensor" display for output voltage.
4. Start the engine. Run the engine at idle
for warm-up.
5. Observe the "Common Rail Pressure
Sensor" display for output voltage again.
Was the voltage within range?
Check the common rail pressure sensor
circuit for +B short.
1. Starter switch "OFF".
2. Disconnect the ECM.
11
3. At the ECM connector pins, measure the
resistance.
Was the resistance within range?
Repair or replace the faulty harness.
12
Is the action complete?
Action
pin and measure
connect the common
Value(s)
Pins 64-63
(not jumpered):
∞ Ω
Pins 64-
ground
(jumpered):
Pins 1-
ground: 0 Ω
(not jumpered):
∞ Ω
the Pins 63-
ground
(jumpered):
Pins 4-
ground: 0 Ω
(not jumpered):
∞ Ω
—
rail
—
Starter switch
ON:
Approx. 1 V
Idling:
Approx. 1.6 V
Pins 63/67/
66/64-109/
114/115/116:
∞ Ω
—
Engine Control System 1A-211
Yes
Go to Step 9
Verify repair and
go to Step 9
Go to Step 10 Diagnostic Aids
Go to Step 18
Go to Step 13
Verify repair and
go to Step 18
No
Go to Step 8
—
Refer to
Go to Step 11
Go to Step 12
—