Diagnostic Overview
Cummins fault code 2357 typically relates to VGT actuator communication, position feedback, or calibration. The ECM may not be receiving a plausible response from the actuator or may detect that the turbo position is not following command. Causes include failed actuator electronics, power or ground issues, data-link wiring problems, incorrect calibration, sticking turbo vanes, or mechanical turbo wear. Diagnosis should include checking actuator power and ground, inspecting communication wiring, running calibration, and verifying that the turbo mechanism moves freely.