Sorry, the NHTSA has not posted this TSB document yet.
You can still get the detailed info from Mitsubishi for this TSB. Call your local Mitsubishi dealer's service department & ask for a copy of TSB# 0313008.
DIAGNOSTIC TROUBLESHOOTING INSTRUCTIONS IN SERVICE MANUAL FOR MFI DIAGNOSTIC TROUBLE CODE (DTC) P0638 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE PROBLEM ARE INCORRECT. THIS BULLETIN CONTAINS CORRECTED TROUBLESHOOTING INSTRUCTIONS FOR DTC P0638. *TT