U3003 Code: Meaning, Causes, and Symptoms | OBD2 Codes
U3003 – ABS Module Battery Voltage
U3003 Possible Symptoms
Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)
U3003 Possible Causes
Faulty Anti-Lock Brake System (ABS) Module,Anti-Lock Brake System (ABS) Module harness is open or shorted,Anti-Lock Brake System (ABS) Module circuit poor electrical connection
The Anti-Lock Brake System (ABS) Module, hydraulic pump and solenoid valves require an operating voltage that is between 10 and 17 volts. The ABS module receives this voltage from the BJB. The ABS module has a single ground circuit located in the engine compartment wiring harness. Excessive resistance or an open in one or more of these circuits, a discharged battery or a inoperative charging system results in the ABS module setting a DTC. Internally to the ABS module, the ignition voltage supply circuit is used as a redundant back up for the battery voltage supply circuit in case the battery voltage supply circuit is interrupted. If the battery voltage supply circuit is interrupted, the ABS module immediately shuts off and does not enter the power latch mode. The module uses the power latch mode to write certain parameters (such as learned offsets numbers) to non-volatile memory. At the beginning of each ignition cycle, a counter value is increased by 1 after a specified vehicle speed has been reached and a specified time has elapsed. When the ABS module enters the power latch mode, this counter is reset to 0.