general information - Martin Nez

FI SYSTEM DIAGNOSIS 4-67“C29” (P1654-H/L) STP SENSOR CIRCUIT MALFUNCTIONC29DETECTED CONDITIONSignal voltage is not within the followingrange.Difference between actual throttle openingand opening calculated by ECM islarger than specified value.0.15 V Sensor voltage < 4.85 VP1654 Sensor voltage is higher than specifiedHvalue.Sensor voltage is lower than specifiedLvalue.POSSIBLE CAUSE• STP sensor maladjusted• STP sensor circuit open or short• STP sensor malfunction• ECM malfunction• STP sensor circuit shorted to VCC or ground circuitopen• STP sensor circuit open or shorted to ground orVCC circuit openECMRY/WB/BrVCCSTPE2STP sensorINSPECTIONStep 1 (When indicating C29:)1) Turn the ignition switch to OFF.2) Lift and support the fuel tank. (5-3)3) Remove the air cleaner box and lift up the throttle body.(5-13)4) Check the STP sensor coupler for loose or poor contacts.If OK, then measure the STP sensor input voltage.5) Disconnect the STP sensor coupler.6) Turn the ignition switch ON.7) Measure the voltage at the R wire A and ground.8) Also, measure the voltage at the R wire A and B/Br wire C.1