大正汽車

Customer complaint: Check engine light is on,and the transmission won't shift from 3rd to 4th gear.

Connect the diagnostic tool to OBD-II to read the DTC,the error code is about bank2 knock sensor. This code will lead to losing the 4th gear. So,if you read knock sensor relative codes please fix it first.I recommend you to replace both knock sensors together,intake gaskets and the coolant hose which is under the intake manifold, because it is not a easy job to do.

View before the replacement

 Intake manifold removal

Now, you can see the knock sensors 

Parts location diagram

I hope this article that helps you to fix the 4th gear shift problem.