Isuzu N 2008 Series Workshop Manual page 81

1A-78 Engine Control System (4JJ1)
Step
1. Turn OFF the ignition.
2. Disconnect
connector.
3. Inspect
connections and corrosion at the harness
connector of the FRP regulator (pins 1 and 2
of E17).
4. Disconnect the ECM harness connector.
4
5. Inspect
connections and corrosion at the harness
connector of the ECM (pins 89, 97, 105 and
113 of E12).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect
connector.
3. Inspect
connections and corrosion at the harness
connector of the FRP sensor (pins 1, 2 and 3
of E19).
4. Disconnect the ECM harness connector.
5
5. Inspect
connections and corrosion at the harness
connector of the ECM (pins 82, 87, 90 and
101 of E12).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Place the transmission in Neutral and set the
parking brake.
3. Start the engine.
4. Accelerate the engine between idle and
W.O.T. (accelerator pedal full travel) many
6
times while observing the Fuel Rail Pressure
and Desired Fuel Rail Pressure parameter
with a scan tool.
Does the Fuel Rail Pressure parameter follow
within the specified value quick enough (compare
with a similar unit if available)?
Notice: An intermittent problem by foreign material
in the fuel is suspected.
Replace the fuel filter element. Refer to Fuel Filter
7
Element in Section 1D Engine Fuel.
Did you complete the replacement?
Replace the FRP sensor. Refer to Fuel Pressure
Sensor in Section 1D Engine Fuel.
8
Did you complete the replacement?
Action
the FRP regulator
for an intermittent,
for an intermittent,
the FRP sensor
for an intermittent,
for an intermittent,
Value(s)
harness
for poor
—
for poor
harness
for poor
—
for poor
± 5 MPa (± 725
psi)
—
—
Yes
Go to Step 10 Go to Step 6
Go to Step 10 Go to Step 8
Go to Step 7 Go to Step 9
Go to Step 10
Go to Step 10
No
—
—