Subaru 2009 IMPREZA Service Manual page 873

Diagnostic Trouble Code (DTC) Detecting Criteria
CC:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE
(BANK 1)
1. OUTLINE OF DIAGNOSIS
Judge as NG when the target opening angle and actual opening angle is mismatched or the current to motor
is the specified duty or more for specified time continuously.
2. COMPONENT DESCRIPTION
(3)
(1) Motor
(2) Throttle position sensor
3. ENABLE CONDITIONS
Secondary Parameters
Ignition switch
Normal operation of electronic throttle
control
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously when the electronic throttle control is operating.
5. DIAGNOSTIC METHOD
Judge as OK and clear the NG when the malfunction criteria below are met.
Judgement Value
Malfunction Criteria
Difference between target opening angle
and actual opening angle
Output duty to drive circuit
Time Needed for Diagnosis:
• Target opening angle and actual opening angle: 250 milliseconds (For NG) 2000 milliseconds (For OK)
• Output duty to drive circuit: 2000 milliseconds
(4)
(3) Engine control module (ECM)
Enable Condition
ON
ON
Threshold Value
3.5° or less
95% or less
GD(H4SO)-149
GENERAL DESCRIPTION
(1)
(2)
(4) Drive circuit
EN-01863