This Preliminary Information communication provides information to the technician about vehicles with a Service Engine Soon Malfunction Indicator Lamp on. Technician may find Diagnostic Trouble Codes P011, P0014, P0021, and or P0024. During inspection if no other drivability concerns found inspect the engine unit number sticker for an (A) before the sequence number. If there is an "A" before the sequence number, then replace the Overhead valve/Cam Actuator Solenoid Valve with a replacement "service" valve.