DTC P1551: Throttle Rest Position Not Reached During Learn: Description

The Engine Control Module (ECM) controls the throttle blades by applying a varying voltage to the throttle valve motor. The ECM monitors the actual throttle blade position using Throttle Position (TP) sensor 1 and 2. If the ECM detects the throttle blade did not return to the rest position during the learn procedure, DTC P1551 sets.