Audi A3 1.4 TFSI: engine running on three cylinders and EPC light on
A 2016 Audi A3 with the 1.4 TFSI CZEA engine came in with an engine that sometimes ran on three cylinders, accompanied by an illuminated EPC light. The memory contained one fault: the camshaft actuator of cylinder 3 was giving an implausible signal. The fault could not be repeated on command.
The highlights
An Audi A3 Sedan with a CZEA engine from 2016
Trouble Code: 14313 - Exhaust Cam Adjustment Actuator B; Cylinder 3
P11D8 00 [00100000] - Implausible Signal
The complaint was not reproducible during the test drive.
I was allowed to take the car for my commute. This way, the customer did not pay for labor hours waiting for a breakdown that never materialized.
Clearing a fault code and waiting is not a diagnosis. I wanted to see the fault return with the same fault code before replacing anything.
What the error code says
1 Fault Found in Engine 01:
14313 - Exhaust Cam Adjustment Actuator B; Cylinder 3
P11D8 00 [00100000] - Implausible SignalThe code points to the actuator that adjusts the exhaust camshaft of cylinder 3. The control unit is not receiving the expected signal after the actuator has been actuated. (Implausible Signal). Therefore, the code does not indicate what is broken. It only states that the feedback from the actuator does not match the command. This could be the part, but also the wiring, the connector, or the control signal in the ECU.
The operation of the system
The 1.4 TFSI features the Audi Valvelift System (AVS), also known as cylinder deactivation. Under low to medium load, the engine deactivates two cylinders, allowing it to run on two cylinders and save fuel. The system achieves this using actuators that adjust the exhaust cams of those cylinders, preventing the valves from opening.
As soon as power is needed again, the actuator must downshift the camshaft and re-engage the cylinder. The ECU monitors this and checks whether the actuator has executed the command correctly.
Want to read more?
Subscribe to villaincustomworks.com to keep reading this exclusive post.
