AutoCodes – Lincoln – B12AB Lincoln

B12AB Lincoln Code - Drivers Heated Seat Relay Drive Circuit Shorted To Battery Voltage

Quick Answer

The Heating, Ventilation, and Air-Conditioning (HVAC) Module contains the driver heated seat control button and indicator. Common causes include Faulty Heater Seat Relay, Faulty Heater Mat, Heater Mat harness is open or shorted. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B12AB Lincoln indicates Drivers Heated Seat Relay Drive Circuit Shorted To Battery Voltage.
Common causes: Common causes include Faulty Heater Seat Relay, Faulty Heater Mat, Heater Mat harness is open or shorted.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 735

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B12AB Lincoln Description

The Heating, Ventilation, and Air-Conditioning (HVAC) Module contains the driver heated seat control button and indicator. The heated seat system functions independently from the climate control system. A heated seat relay is located underneath the driver seat cushion frame. There are 2 voltage supplies to the heated seat relay. Voltage is supplied from the Smart Junction Box (SJB) heated seat relay enable circuit to the driver heated seat relay coil when the engine is running. Ground is supplied to the opposite side of the driver relay coil by the HVAC module driver heated seat relay drive circuit when the driver heated seat switch button is pressed to energize the relay. This closes the relay contacts to supply battery voltage from the SJB circuit to the driver heater mat circuit. The driver heater mats are directly connected to ground circuit completing the electrical circuit to heat the seat.

OBDII Code B12AB Lincoln - Drivers Heated Seat Relay Drive Circuit Shorted To Battery Voltage - AutoCodes.com — B12AB Lincoln Code - Drivers Heated Seat Relay Drive Circuit Shorted To Battery Voltage

What does this mean?

What are the Possible Causes of the DTC B12AB Lincoln?

Faulty Heater Seat Relay
Faulty Heater Mat
Heater Mat harness is open or shorted
Heater Mat circuit poor electrical connection
Faulty Heating, Ventilation, and Air-Conditioning (HVAC) Module

How to Fix the DTC B12AB Lincoln?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B12AB Lincoln code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B12AB Lincoln Code

What does the OBDII code B12AB mean for a Lincoln vehicle?

The B12AB code indicates a fault in the driver's heated seat relay drive circuit, specifically that it is shorted to battery voltage, which can prevent the heated seat from functioning properly.

What are the common symptoms associated with the B12AB code?

Common symptoms include the driver's heated seat not working, the heated seat indicator light not turning on, and potential issues with other electrical components in the seat.

What could cause the B12AB code to trigger?

The code can be triggered by a short circuit in the wiring, a faulty heated seat relay, a defective heated seat element, or issues with the seat control module.

How can I diagnose the B12AB code?

Start by inspecting the wiring and connectors for any visible damage or corrosion. Use a multimeter to check for continuity and ensure the relay is functioning correctly.

What are some common repairs for the B12AB code?

Repairs may include replacing a damaged wiring harness, replacing the heated seat relay, fixing or replacing the heated seat element, or reprogramming the seat control module.

Can I drive my Lincoln with the B12AB code active?

While it is possible to drive the vehicle, it is advisable to address the issue promptly to avoid potential electrical problems and ensure the safety of the heated seat system.

Is it safe to attempt repairs on my own for the B12AB code?

If you have experience with automotive electrical systems, you may attempt repairs. However, if you're unsure, it's best to consult a professional technician to avoid further damage.

How can I clear the B12AB code after repairs?

After completing the necessary repairs, you can use an OBDII scanner to clear the code, or you can disconnect the vehicle's battery for a few minutes to reset the system.

Will ignoring the B12AB code cause other problems?

Yes, ignoring the B12AB code may lead to further electrical issues in the seat system or other related components, potentially resulting in more costly repairs in the future.