☰
Find a Shop |  Search
✕
Engine-Codes - Generic - B12A4

B12A4 - Mode Door Actuator Drive Circuit Shorted To Battery Voltage

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

B12A4 Possible Causes

What does this mean?
  • Stuck or damaged linkage or door
  • Faulty Mode Door Actuator
  • Mode Door Actuator harness is open or shorted
  • Mode Door Actuator circuit poor electrical connection
  • Electronic Manual Temperature Control (EMTC) Module
  • Electronic Automatic Temperature Control (EATC) Module

How is the B12A4 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 B12A4 code

Labor: 1.0

The cost to diagnose the B12A4 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.
How much do you know about cars?

Take the AutoCodes.com automotive tests and turbo-charge your car repair knowledge

Play Now

Possible Symptoms

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

B12A4 Meaning

Under normal operation, to rotate the mode door actuator clockwise, the Electronic Manual Temperature Control (EMTC) or Electronic Automatic Temperature Control (EATC) module supplies voltage and ground to the floor/defrost/panel mode door actuator motor through the circuit. To rotate the mode door actuator counterclockwise, the EMTC module or EATC module reverses the voltage and ground circuits.
The mode door actuator feedback resistor is supplied a ground from the EMTC module or EATC module and a 5-volt reference voltage. The EMTC module or EATC module reads the voltage on the mode door actuator feedback circuit to determine the mode door actuator position by the position of the actuator feedback resistor wiper arm.

More Information

Need more information on how to fix the B12A4 code?
Get Access to Factory Service Manuals

Information for specific makes

  • B12A4 FORD Mode Door Actuator Drive Circuit Shorted To Battery Voltage
  • B12A4 LINCOLN Mode Door Actuator Drive Circuit Shorted To Battery Voltage
  • B12A4 MERCURY Mode Door Actuator Drive Circuit Shorted To Battery Voltage

Need more help?

Get the B12a4 code diagnosed by a professional: Find a repair shop in your area

Related Information