AutoCodes – Mercury – B12AD Mercury

B12AD Mercury Code - Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage

Quick Answer

The Heating, Ventilation, and Air-Conditioning (HVAC) Module contains the passenger 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: B12AD Mercury indicates Passenger 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 712

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B12AD Mercury Description

The Heating, Ventilation, and Air-Conditioning (HVAC) Module contains the passenger 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 passenger 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 passenger heated seat relay coil when the engine is running. The ground is supplied to the opposite side of the passenger relay coil by the HVAC module from the passenger heated seat relay drive circuit when the passenger 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 passenger heater mat circuit. The passenger heater mats are directly connected to ground circuit completing the electrical circuit to heat the seat.

OBDII Code B12AD Mercury - Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage - AutoCodes.com — B12AD Mercury Code - Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage

What does this mean?

What are the Possible Causes of the DTC B12AD Mercury?

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 B12AD Mercury?

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 B12AD Mercury 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 B12AD Mercury code?

Need more information on how to fix the B12AD Mercury code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B12AD Mercury 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 B12AD Mercury Code

1. What are the common symptoms of OBDII code B12AD in a Mercury related to the Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- The common symptoms include the passenger heated seat not functioning, seat heat turning on/off erratically, or the seat heating up excessively.

2. What are the possible causes of OBDII code B12AD Mercury related to the Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- The possible causes may include a short circuit in the wiring harness, a faulty relay, a damaged seat heating element, or a malfunctioning control module.

3. How can I diagnose the issue related to OBDII code B12AD in a Mercury Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- Diagnosis typically involves inspecting the seat wiring, checking the relay operation, testing the seat heating element, and scanning the vehicle's control modules for fault codes.

4. Can I drive my Mercury with OBDII code B12AD indicating a Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to prevent further electrical problems or potential seat heating hazards.

5. How can I repair OBDII code B12AD in my Mercury for the Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- Repairing the issue may involve repairing the wiring harness, replacing the faulty relay, fixing the seat heating element, or reprogramming the control module as necessary.

6. Are there any quick tips to troubleshoot OBDII code B12AD Mercury Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- Quick troubleshooting tips include checking the fuse related to the seat heating circuit, ensuring proper connections, and using a multimeter to test for continuity in the wiring.

7. Is it possible to reset the OBDII code B12AD in a Mercury Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage without repairs?

- While clearing the fault code may temporarily turn off the warning light, it is not recommended as the underlying issue causing the code will persist and may lead to further problems.

8. Can a DIY enthusiast without professional automotive experience fix OBDII code B12AD Mercury Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- Depending on the specific cause, a DIY enthusiast with some electrical knowledge may be able to address certain aspects of the issue, such as checking connections or replacing a relay.

9. How long does it typically take to repair OBDII code B12AD in a Mercury for the Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- The repair time can vary based on the exact cause of the issue, but it may take anywhere from 1-3 hours for a professional technician to diagnose and fix the problem.

10. What are the potential risks of ignoring OBDII code B12AD Mercury Passenger Heated Seat Relay Drive Circuit Shorted To Battery Voltage?

- Ignoring the code can lead to continued seat heating malfunctions, electrical shorts, potential fire hazards, or damage to other components in the vehicle's electrical system.