Isuzu 2008MY N Series Workshop Manual page 230

Step
1. Leave the DMM connected to the EGR valve
harness connector.
2. Turn OFF the ignition.
3. Disconnect the fuel rail pressure (FRP) sensor
5
harness connector.
4. Turn ON the ignition, with the engine OFF.
Does the DMM voltage change to more than
the specified value?
1. Leave the DMM connected to the EGR valve
harness connector.
2. Turn OFF the ignition.
3. Disconnect the camshaft position (CMP)
6
sensor harness connector.
4. Turn ON the ignition, with the engine OFF.
Does the DMM voltage change to more than
the specified value?
1. Leave the DMM connected to the EGR valve
harness connector.
2. Turn OFF the ignition.
3. Disconnect the barometric pressure (BARO)
7
sensor harness connector.
4. Turn ON the ignition, with the engine OFF.
Does the DMM voltage change to more than
the specified value?
1. Leave the DMM connected to the EGR valve
harness connector.
2. Turn OFF the ignition.
3. Disconnect the accelerator pedal position
8
(APP) sensor harness connector.
4. Turn ON the ignition, with the engine OFF.
Does the DMM voltage change to more than
the specified value?
1. Test the 5 volts reference circuit 2 between the
ECM (pin 61 of J-14) and the following
components for a short to ground or short to
the low reference circuit:
• APP sensor 2 (pin 1 of B-5)
• BARO sensor (pin 3 of B-121)
2. Test the 5 volts reference circuit 5 between the
ECM (pin 87 of E-12) and the following
9
components for a short to ground or short to
the low reference circuit:
• FRP sensor (pin 3 of E-19)
• CMP sensor (pin 3 of E-18)
• EGR valve position sensor (pin 1 of E-15)
3. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Action
Engine Control System (4HK1)
Value(s) Yes
4.5volts
Go to Step 12
4.5volts
Go to Step 13
4.5 volts
Go to Step 14
4.5 volts
Go to Step 15
—
Go to Step 17
1A-227
No
Go to Step 6
Go to Step 7
Go to Step 8
Go to Step 9
Go to Step 16