Possible causes – Variable camshaft timing actuator stuck in advance position– Timing belt jumped Symptoms – Engine Light ON (or Service Engine Soon Warning Light)– Lack/Loss of power– Engine rough idle MAZDA Related P0021 code 2009 MAZDA TRIBUTE Power Train:automatic Transmission:control Module (tcm, Pcm) 2009 MAZDA TRIBUTE Equipment:other:owners/service/other Manual