Engine-Codes - Mercury - B12B1 MERCURY

B12B1 MERCURY - Front Blower Motor PWM Drive Circuit Shorted To Voltage

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

B12B1 MERCURY Possible Causes

  • Faulty Blower Motor Speed Control Module
  • Blower Motor Speed Control Module harness is open or shorted
  • Blower Motor Speed Control Module circuit poor electrical connection
  • Faulty Electronic Automatic Temperature Control (EATC) Module

How is the B12B1 MERCURY code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the B12B1 MERCURY code

Labor: 1.0

The cost to diagnose the B12B1 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

B12B1 MERCURY Meaning

Under normal operation, the blower motor relay coil receives ground from the Electronic Automatic Temperature Control (EATC) Module through the circuit. The coil receives ignition voltage through the circuit. Voltage is supplied to the relay switch contact. When the relay coil is energized, the voltage is delivered to the blower motor and the blower motor speed control module through the circuit. Ground for the motor is provided through the circuit from the blower speed control module. Ground for the blower motor speed control module is provided by the circuit. The EATC module sends a Pulse Width Modulation (PWM) signal to the Blower Motor Speed Control Module through a circuit to control the blower speed.

More Information

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