Isuzu 1999 RODEO Workshop Manual page 861

6E1–234 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DTC P0401 – Exhaust Gas Recirculation Flow Insufficient Detected
Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 1. Start the engine.
2. Monitor the MAP signal with a Tech 2 while idling.
3. While idling, depress the accelerator pedal about
halfway down and immediately let the engine return
to idle.
Did the MAP value on the Tech 2 show an immediate
large change?
3 Replace the MAP sensor.
4 1. Inspect the exhaust system for modification of
original installed parts or leaks.
2. If a problem was found, repair exhaust system as
necessary.
Was a condition present that required repair?
5 1. Remove the EGR valve.
2. Visually and physically inspect the pintle, valve
passages and the adapter for excessive deposits or
any kind of a restriction.
3. If a problem if found, clean or replace EGR system
components as necessary.
Was a condition present that required repair?
6 1. Remove the EGR inlet and outlet pipes from the
exhaust manifold and the intake manifold.
2. Inspect the manifold EGR ports and the EGR inlet
and outlet pipes for a blockage caused by excessive
deposits or other damage.
3. If a problem is found, correct the condition as
necessary.
Was a condition present that required repair?
7 1. Review and record the Tech 2 Failure Records data.
2. Clear Diagnostic Trouble Code and monitor the
Tech 2 System Info Screen while operating the
vehicle as specified in "Diagnostic Aids."
3. Using a Tech 2, monitor "Diagnostic Trouble Code"
info for Diagnostic Trouble Code P0401 until the
Diagnostic Trouble Code P0401 test runs.
4. Note the test result.
Does the Tech 2 indicate Diagnostic Trouble Code
P0401 failed this ignition?
Action Value(s) Yes
— Go to Step 2
— Go to Step 4
— Verify repair
— Go to Step 7
— Go to Step 7
— Go to Step 7
— —
No
Go to OBD
System
Check
Go to Step 3
—
Go to Step 5
Go to Step 6
Refer to
Diagnostic
Aids
Repair
complete