This code indicates that the primary vehicle network has lost communication with a specific node in the restraints (airbag) system designated as Sensor E. It typically signifies a wiring fault, a failed sensor, or a network bus issue rather than a failure of the main computer.
Open circuits, corroded pins, or chafed wires leading to Sensor E are the most common reasons for lost communication.
The designated restraints sensor itself may have internally failed and stopped transmitting data on the network.
A shorted or open controller area network (CAN) bus circuit will drop communication to specific modules or sensors.
Insufficient system voltage can cause modules and sensors to drop off the network and trigger communication codes.
A failure of the main control module is extremely rare for this code and should only be considered after all other possibilities are eliminated.
The designation 'Sensor E' is manufacturer-specific and refers to a particular device on the restraints network, such as a crash sensor, seat position sensor, or occupant weight sensor; you must consult the service manual to identify it for your specific vehicle.
It is not recommended. Because the restraints system cannot communicate with this sensor, the airbags may not deploy properly in a crash, or they may deploy unexpectedly.
No, replacing the Powertrain Control Module (PCM) is almost never the correct fix for U0174. The code means the PCM cannot hear from Sensor E, which is almost always caused by a wiring issue or a fault with the sensor itself, not the module doing the listening.
You can clear the code, but if the hard fault remains, the code will return immediately upon cycling the ignition. Clearing the code does not fix underlying wiring or sensor failures.