2009 Volkswagen Jetta

Disconnect both O2 sensors (front and rear), start engine and let idle. Check MVB's 41/4 and 136/4 and verify have both changed from a 1 to a 0 (you may have to drive the car 4 miles to get them to reset to 0). Also a key cycle may be required for values to reset. This forces the ECM to re-learn the O2 sensor adaptation. Once MVB 41/4 and 136/4 read 0, re-connect the O2 sensors, road test and recheck for faults.

When diagnosing a generator charging concern, it is recommended to verify operation of the one way clutch located in the generator pulley (if equipped) before replacing generator assembly. To check the one way clutch, remove the belt from the generator pulley and use a trim removal tool to hold fan blades inside generator, as shown below. When attempting to turn pulley by hand with fan blades held, pulley should spin freely in only one direction. If pulley spins freely in both directions, the one way clutch has failed and should be replaced before continuing diagnosis.

Incorrect torque converter or flywheel/flexplate installation can result in transmission damage. When installing an engine, flywheel or transmission, please follow the installation procedures outlined in ELSA. For the flywheel/flexplate, please be certain the correct shim is installed between it and the crankshaft (reference VWIQ120). When installing a torque converter, press the torque converter hub through the seal as far as the first stop. Turn the torque converter while pushing toward the transmission using light force, until the cut outs in the torque converter hub lock into the pump wheel plate. The torque converter slides in. The torque converter is installed correctly if it is easy to turn by hand and if it fits evenly in the transmission bell housing. Additionally, it should spin freely when the transmission bell housing bolts are torqued to the engine block, prior to installation of the flywheel to converter bolts (reference VWIQ121).