Dtc P0638 (Flash Code 61) - Isuzu 2008MY N Series Workshop Manual

DTC P0638 (Flash Code 61)

Circuit Description
The ECM controls the intake throttle valve opening
based on the engine running condition and by
controlling the intake throttle solenoid. The intake
throttle valve position is detected by the position
sensor, and relayed to the ECM. If the ECM detects a
variance between the actual intake throttle valve
position and desired intake throttle valve position while
the intake throttle solenoid is commanded ON, this
DTC will set.
Condition for Running the DTC
• DTCs P0122, P0123, P060B and P0697 are not
set.
• The battery voltage is between 18 to 32 volts.
• The ignition switch is ON.
• The desired intake throttle valve position is stable.
• The intake throttle solenoid is commanded ON.
Condition for Setting the DTC
• The ECM detects that the difference between the
actual and the desired intake throttle position is
more than 40% for longer than 5 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the MIL on the second
consecutive driving cycle when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type B. (Euro 4
specification)
Circuit/ System Testing DTC P0638
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 P0122 or P0133 also set?
1. Perform the Intake Throttle Solenoid Control
with a scan tool several times.
2. Command the Desired Intake Throttle Position
Increase and Decrease while observing the
3
Intake Throttle Position.
Does the Intake Throttle Position parameter
follow within the specified value quick enough
(compare with a similar unit if available)?
Action
Engine Control System (4HK1)
• The ECM illuminates MIL when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type A. (Except Euro
4 specification)
Condition for Clearing the DTC
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type B. (Euro 4
specification)
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type A. (Except Euro 4
specification)
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
• A sticking or intermittently sticking intake throttle
valve may set this DTC.
• A sticking intake throttle valve at full closed
position will cause engine starting problem.
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
± 5%
Go to Diagnostic
Aids
1A-217
No
Go to Diagnostic
System Check -
Engine Controls
Go to Step 3
Go to Step 4