DTC P0638 Cadillac
TAC Motor System Malfunction
TAC Motor System Malfunction
Description
Engine started, system voltage over 10v, IAT sensor over 41ºF, ECT sensor from 41-212ºF, and the PCM detected the required PWM signal to move the throttle blade was more than a predetermined value. The ECM opens the throttle blades by controlling the thro
Cause and Solution
TAC motor control circuit is open, shorted to ground or shorted to system power (B+)
Throttle valves not in their rest position
Throttle valves binding open or binding closed
Throttle valves moving open or closed without spring pressure
Video Guide
Diagnostic Info
- DTC Code: P0638
- Brand: Cadillac