On this video we see a very common code that we, tranny builders, see a lot. The reason for this is that if one or more of your speed sensors are not reading what they're supposed to see, the vehicle will go into what we call Limp In Mode or Fail Safe mode. For example, a Gear Ratio Error code will cause the PCM to go into Limited Power to avoid any further damage to the transmission. Once the repairs have been made, By resetting the Keep Alive Memory will get the vehicle out of this mode. It will not go out of Limited Power Mode by just clearing codes, you must reset the KAM from the PCM.
If you're a drive-ability technician, you might have seen this code before. The most common issue would be a faulty EGR Sensor Module or a MAF sensor, or anything related to emission control, but not all. On this vehicle was the VSS mounted in the differential. For the transmission to function properly, it uses all 3 speed sensors mounted on the transmission plus the wheel speed sensors to calculate vehicle speed, load and torque for optimal performance.
11 сен 2024
