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U300E MERCURY

U300E MERCURY - ABS Module Ignition Input On

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What does this mean?

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
  • Tech notes

    This DTC sets in continuous memory if the power mode message from the BCM indicates the ignition is ON, but the ignition voltage supplied to the ABS module is missing.

    Possible symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • U300e Mercury Description

    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.

    OBDII Code U300e Mercury - ABS Module Ignition Input On - Engine-Codes.com

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