Q: 2011 Dodge Avenger Transmission

Hello. The most basic way to put it is the 3rd and 4th gear are slipping. What was your concern when you had the car diagnosed? Was is just the Check Engine Light, or did you notice a problem with the transmission. The engine and transmission computer (PCM) closely monitors the transmission for malfunctions. It uses the input of 3 speed sensors.

Here is an example. We’ll say that 3rd gear is 2:1, and 4th gear is 1:1. If the engine is spinning at 4000 rpm, then the output of the transmission in 3rd gear should be 2000 rpm. In 4th it would be 4000 rpm.

If the output sensor is not reading this specific rpm, the computer will set an incorrect ratio code. The gears themselves do not slip, the clutch packs that hold the gear can slip for many reasons. Now there are two things that can be going on.

The computer is correct, the gears are slipping. You will most likely know when the transmission is slipping when the computer is wrong. It could be a sensor misinterpretation or malfunction. Now, no matter what, if the code sets, the PCM will put the car into "limp" mode. You will notice this. The engine will have reduced power and the transmission will default to a preset gear. It is very possible that the transmission will need to be replaced due to this condition as long as it was properly diagnosed. You may want to have another expert inspect the car for you in person to ensure that the proper diagnosis was made.