Isuzu N 2008 Series Workshop Manual page 61

1A-58 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 sensor (pins 1, 2 and 3
of E19).
4. Disconnect the ECM harness connector.
6
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?
Replace the FRP sensor. Refer to Fuel Pressure
Sensor in Section 1D Engine Fuel.
7
Did you complete the replacement?
Repair the short to ground between the ECM (pins
89 and 97 of E12) and the FRP regulator (pin 2 of
8
E17).
Did you compete the repair?
1. Check for normal readings at key up for the
following sensor inputs: Use the Scan Tool
Data List or a known good vehicle to
determine nominal values.
• Engine Coolant Temperature Sensor
• Barometric Pressure (BARO) Sensor
9
• Boost Pressure Sensor
• Intake Throttle Position Sensor
2. Repair the circuit(s) or replace the sensor as
necessary.
Did you find and correct the condition?
1. Other possible causes for the no-start
condition:
• Engine mechanical timing
• Heavily restricted intake or exhaust
plugged solid.
10
• Poor engine compression.
• Water or gasoline contamination in fuel.
2. Repair as necessary.
Did you find and correct the condition?
1. Reconnect
harness connector(s).
2. Turn OFF the ignition for 30 seconds.
11
3. Attempt to start the engine.
Does the engine start and continue to run?
Observe the DTC Information with a scan tool.
12
Are there any DTCs that you have not diagnosed?
Action
the FRP sensor
for an intermittent,
for an intermittent,
all previously disconnected
Value(s)
harness
for poor
—
for poor
—
—
—
—
—
—
Yes
Go to Step 11 Go to Step 7
Go to Step 11
Go to Step 11
Go to Step 11 Go to Step 10
Go to Step 11
Go to Step 12 Go to Step 2
Go to DTC List
No
—
—
—
System OK