Dtc P1404 (Flash Code 45) - Isuzu 2008MY N Series Workshop Manual

DTC P1404 (Flash Code 45)

Circuit Description
The ECM controls the EGR valve opening based on the
engine running condition and by controlling the EGR
solenoid. The EGR valve position is detected by the
position sensor, and relayed to the ECM.
If the ECM detects that the actual EGR position is
higher than certain amount, this DTC will set. (Closed
Position Error DTC)
If the ECM detects a variance between the learned
closed position and actual closed position, this DTC will
also set. (Learned Position Error DTC)
Condition for Running the DTC
Closed Position Error DTC
• DTCs P0112, P0113, P0116, P0117, P0118,
P0409, P060B, P0651, P0651, P0697 and P2227
are not set.
• The battery voltage is between 16 to 32 volts.
• The desired EGR valve position is stable.
Learned Position Error DTC
• DTCs P0404, P0409, P0500, P0502, P0503,
P060B and P0651 are not set.
Condition for Setting the DTC
Closed Position Error DTC
• The ECM detects that the difference between the
actual and the desired EGR valve position is more
than 15% for longer than 5 seconds.
Learned Position Error DTC
Circuit/ System Testing DTC P1404
Step
Did you perform the Diagnostic System Check
1
- Engine Controls?
1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
2
4. Monitor the DTC Information with a scan tool.
Is DTC P0404 or P0409 also set?
1. Remove the EGR valve assembly from the
engine.
2. Inspect the EGR valve for the following
conditions:
• Restricted
materials
3
• Excessive deposits at valve
• Bent valve shaft or valve
3. Repair or replace as necessary.
Did you find and correct the condition?
Action
EGR valve by foreign
Engine Control System (4HK1)
• The ECM detects that the EGR learned minimum
position is not within a predetermined range when
the ignition switch is OFF.
Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic
runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
Condition for Clearing the MIL/DTC
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type A.
Notice: A history
(accumulated engine runtime) and will not clear with a
scan tool. (Euro 4 specification)
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
• A sticking or intermittently sticking the EGR valve
may set this DTC.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Value(s) Yes
—
Go to Step 2
—
Go to Applicable
DTC
—
Go to Step 7
DTC remains 9,600
No
Go to Diagnostic
System Check -
Engine Controls
Go to Step 3
Go to Step 4
1A-241
hours