Isuzu 2008MY N Series Workshop Manual page 249

1A-246 Engine Control System (4HK1)
Step
1. Inspect the following conditions:
• Misrouted
differential pressure hoses or pipes
Important:
directionality in the exhaust differential
pressure
System in Section 1G Engine Exhaust .
• Plugged, crushed or kinked exhaust
differential pressure hoses or pipes
• Physical
differential pressure sensor
• Any contamination or objects that block
the exhaust differential pressure sensor
port
• Skewed or slow exhaust differential
pressure sensor
• An exhaust system gasket that is missing
or damaged
• Exhaust gas leakage from the exhaust
2
pipe, gasket, DPD assembly, exhaust
temperature
differential pressure hoses or pipes
• Modified exhaust system
• Skewed or slow exhaust temperature
sensors
• Restricted air cleaner element, restricted
or collapsed air tubing between the air
cleaner and the intake manifold
• Modified air induction system
• Any air induction leak
• Any contamination or objects that block
the mass air flow (MAF) sensor inlet
• Skewed or slow MAF sensor
2. Repair or replace as necessary.
3. Reconnect
harness connector(s) or components.
Did you find and correct the condition?
1. Turn ON the ignition for 30 seconds. DO NOT
start the engine. Make sure the DPD lamp or
"AUTO
indicators on the instrument panel cluster is
turned OFF. (This is to relearn exhaust
differential pressure sensor.)
2. Turn OFF the ignition for 30 seconds.
3
3. Start the engine.
4. Observe the DPD Accumulation Status and
DPD Distance Status with a scan tool and plot
both readings on the DPD status table. Refer
to DPD Status Table in DPD Control System
Check.
Is the intersected range located in C or D?
Action
or disconnected
There is
hoses. Refer to
damage of the
sensor(s) or
all previously disconnected
REGEN.", "MANUAL
Value(s)
exhaust
installation
Exhaust
exhaust
—
exhaust
REGEN."
—
Yes
Go to Step 5 Go to Step 3
Go to Step 4 Go to Step 5
No