Lazima iwake maana the way gari ilivokua designed ilikua ni auto.. so control box (ECU) is not getting any inputs from transmission module to alter engine output parameters...
Ie Ecu haipata taarifa ya gearbox ipo katika gear namba ngapi, je gear shifter ipo katika position gani;; je parking? Reverse? Drive? Neutral? So kwakua hizi inputs zote hazipo so calibration za injini zinakua out of range matokeo yake inawasha check injini..
NB: taa ya check engine haiwaki kwa hizo sababu walizokupa mafundi wako bali ni kwasababu nilizo kuambia.. (kumbuka gari ilikua ni automatic na control box unayotumia ni ile iliyokuja na hiyo injini so gari ilikua programed kufanya kazi kama automatic and not manual) na automatic car inatumia sensor mbalimbali kuifanya control box ichague appropriate gear ratio..mfano kuna throttle position sensor, engine rpm, speed mfano gari automatic ikifika speed zaidi ya 15km/h lazima control box i-command gear box iende gear ya pili.ili kupunguza rpm ya injini.sasa kwakua imechange to manual, ECU inakosa feedback kila inapo ona speed ni kubwa na ina command gear shifting but no feedback from solenoid responsible for shifting to second gear,so ECU ikiona hizi variations in operation,check injini ina illuminate (waka) but haitakua na shida sana, endelea piga kazi mkuu.