AutoCodes – Mercury – B12AE Mercury

B12AE Mercury Code - Passenger Heated Seat Relay Drive Circuit Open Or Shorted to Ground

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: B12AE Mercury indicates Passenger 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 629

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 B12AE 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 B12AE Mercury - Passenger Heated Seat Relay Drive Circuit Open Or Shorted to Ground - AutoCodes.com — B12AE Mercury Code - Passenger Heated Seat Relay Drive Circuit Open Or Shorted to Ground

What does this mean?

What are the Possible Causes of the DTC B12AE 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 B12AE 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 B12AE 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 B12AE Mercury code?

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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 B12AE Mercury Code

1. What are the common symptoms of OBDII code B12AE in a Mercury related to the passenger heated seat relay drive circuit?

The common symptoms include a non-functioning passenger heated seat, the seat heating turning on/off intermittently, or the seat heating becoming too hot.

2. What are the possible causes of the OBDII code B12AE in a Mercury?

Possible causes include damaged wiring or connectors in the seat heating system, a faulty heated seat relay, a short circuit to ground in the circuit, or a problem with the seat heating control module.

3. How can I diagnose the cause of OBDII code B12AE in my Mercury?

To diagnose the issue, you can perform a visual inspection of the wiring and connectors, test the heated seat relay, check for continuity in the circuit, and use a scan tool to monitor the seat heating system data.

4. Can I still drive my Mercury with the OBDII code B12AE present?

It is generally safe to drive the vehicle with this code, but the passenger heated seat function may not work properly. It is recommended to have the issue diagnosed and repaired to restore full functionality.

5. How can I repair the passenger heated seat relay drive circuit open or shorted to ground in my Mercury?

Repair options include repairing or replacing damaged wiring or connectors, replacing the heated seat relay if faulty, addressing any short circuits in the circuit, or replacing the seat heating control module if necessary.

6. Will resetting the OBDII code B12AE in my Mercury make the issue go away permanently?

Resetting the code may temporarily clear the warning light, but if the underlying issue causing the code is not addressed, the problem is likely to reoccur. It is essential to diagnose and repair the root cause of the code.

7. Can a DIY enthusiast fix the OBDII code B12AE in a Mercury, or is it best left to professionals?

Depending on your skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the issue themselves. However, if you are unsure or inexperienced with automotive electrical systems, it is recommended to seek professional help.

8. Are there any preventive measures to avoid encountering the OBDII code B12AE in my Mercury?

To prevent this issue, you can periodically inspect the seat heating system components for damage, avoid overloading the circuit with aftermarket accessories, and address any electrical issues promptly to prevent damage to the circuit.

9. How long does it typically take to repair the OBDII code B12AE in a Mercury?

The repair time can vary depending on the exact cause of the code and the complexity of the repair. It could take anywhere from a few hours to a full day to diagnose and fix the issue completely.

10. Will fixing the OBDII code B12AE improve the overall reliability of my Mercury's heating system?

Yes, addressing the code B12AE and fixing the underlying issue will improve the reliability of the passenger heated seat system in your Mercury, ensuring that it functions correctly and safely.