AutoCodes – Lincoln – B12AC Lincoln

B12AC Lincoln Code - Drivers Heated Seat Relay Drive Circuit Open Or Shorted to Ground

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: B12AC Lincoln indicates Drivers Heated Seat Relay Drive Circuit Open Or Shorted to Ground.
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 823

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 B12AC 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 B12AC Lincoln - Drivers Heated Seat Relay Drive Circuit Open Or Shorted to Ground - AutoCodes.com — B12AC Lincoln Code - Drivers Heated Seat Relay Drive Circuit Open Or Shorted to Ground

What does this mean?

What are the Possible Causes of the DTC B12AC 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 B12AC 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 B12AC 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.

Need more information about the B12AC Lincoln code?

Need more information on how to fix the B12AC Lincoln code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B12AC Lincoln code diagnosed by a professional: Find a repair shop in your area

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 B12AC Lincoln Code

1. What are the common symptoms of OBDII code B12AC in a Lincoln related to the driver's heated seat relay drive circuit?

The common symptoms include a non-functioning driver's heated seat, no heat getting to the seat, or the seat heater turning on and off intermittently.

2. What are the possible causes of the driver's heated seat relay drive circuit being open or shorted to ground in a Lincoln?

Potential causes include damaged wiring or connectors, a faulty relay, a malfunctioning seat heater control module, or an issue with the seat heating element itself.

3. How can I diagnose the OBDII code B12AC related to the driver's heated seat relay drive circuit in my Lincoln?

You can diagnose this code by performing a visual inspection of the wiring and connectors, testing the relay, checking the seat heater control module, and testing the resistance of the seat heating element.

4. What are some repair tips for fixing the driver's heated seat relay drive circuit open or shorted to ground issue in a Lincoln?

Repair tips include repairing or replacing damaged wiring and connectors, replacing the faulty relay or seat heater control module, and repairing or replacing the seat heating element if necessary.

5. Can I continue driving my Lincoln with the OBDII code B12AC related to the driver's heated seat relay circuit issue?

It is not recommended to continue driving the vehicle with this issue as it may result in discomfort or reduced functionality of the driver's heated seat.

6. Is it possible to reset the OBDII code B12AC related to the driver's heated seat relay drive circuit in a Lincoln?

Resetting the code may temporarily turn off the warning light, but it will likely reappear if the underlying issue is not addressed and repaired.

7. How much does it typically cost to repair the driver's heated seat relay drive circuit issue in a Lincoln?

The cost of repair can vary depending on the specific cause of the issue, but it may range from a few hundred dollars to potentially over a thousand dollars for more complex repairs.

8. Are there any recalls or service bulletins related to the OBDII code B12AC in Lincolns for the driver's heated seat relay drive circuit issue?

It is recommended to check with a Lincoln dealership or visit the National Highway Traffic Safety Administration (NHTSA) website to see if there are any relevant recalls or service bulletins for this specific problem.

9. How can I prevent the recurrence of the OBDII code B12AC in my Lincoln's driver's heated seat relay drive circuit after repair?

Regularly inspecting and maintaining the seat heating system, avoiding overloading the circuit, and ensuring proper installation of any replacement components can help prevent the issue from recurring.

10. Can I attempt to repair the driver's heated seat relay drive circuit issue in my Lincoln myself, or should I seek professional help?

While some simple inspections and repairs can be done by DIY enthusiasts, it is recommended to seek professional help, especially for more complex diagnostic procedures and repairs to ensure the issue is properly addressed.