Code 38, Code 41, Code 42: ESB Does Not Hold Motor: Notes
Expansion Spring Brakes (ESB) are used on front and rear actuator motors. ESB is a mechanical clutch that prevents modulator piston from being back-driven by hydraulic pressure. If motor is back-driven, ABS operation will be disabled and ABS light will illuminate. See Fig 1 .
Code will set if ESB does not hold motor. This code can set during initialization, or if associated hydraulic channel did not reach Anti-Lock Brake System (ABS).