I usually find the heated seat feature among the necessary comfort features in a car, especially during the cold months. However, this feature can develop various issues after years of use, including turning off after a few seconds.
This issue of the heated seat turning off after a few seconds is usually caused by a faulty seat module. An issue with the heating element and wire connection may also be responsible. Here, I would suggest you check the plugs for corrosion, which can cause this issue.
I have listed the potential reasons behind the heated seat disengaging after a few seconds. Read to learn these causes in detail and their solutions, and know how to fix them.
Top 5 Reasons Why Heated Seats Turn Off After a Few Seconds
Despite the great advantage a heated seat has to the drivers, this comfort feature can develop issues. One of these issues is when the driver turns the heated seat on, it turns off after some time.
The heated seat feature can remain on for about ten seconds and sometimes doesn’t last up to five. Whatever the case, this shows an issue with this feature and requires prompt fixing.
I prefer to diagnose the car first using a scan tool, which can help you figure out the issue behind it. A scan tool, like the ODB II, helps clear uncertainty and clear codes.
For instance, when you’re wondering, can cold weather cause abs light to come on? A scan tool can provide answers. Connect your scan tool and check for any issue that may help you determine the cause.
In the following section, I have covered reasons why the heated seat may turn off after some seconds.
1. Faulty Seat Module
A seat module works as an electronic control unit for a car seat, allowing it to perform various functions, including heating. When this module has an issue or malfunctions, it can cause issues with the seat functions.
The module can develop an issue due to electrical disruptions or when the software glitches. However, the module can fail if physically damaged due to impacts or accidents.
When faulty, it interferes with the power supply to various seat components. Also, a malfunction can cause a communication error with the temperature sensor, causing the heater to turn off after a few seconds.
Solutions
Usually, I fix an issue with the seat module by resetting it. The module is under the driver’s seat and hard to access unless the seat is removed at the base. However, to reset the module, you only need to access the switch, which is easier to access.
I prefer accessing it from behind the driver’s seat after moving it forward. Disconnect the seat module for about five minutes to allow it to reset. Reconnect the switch and test the heated seat feature.
Also, disconnecting the battery for some time can reset this module. Actually, disconnecting the battery resets various car features and clears some errors. But will disconnecting the battery unlock doors?
2. Plug Problems
A plug issue is another potential reason behind the heated seat turning off shortly after turning it on. The plugs connect electrical power from the module to the heating elements.
The plug may be dirty or corroded, especially if there was water inside the car sometime back. Corrosion interferes with the electrical transfer between the connectors, and the heating will stop a few seconds after starting.
Solutions
Clean or replace the plugs to fix the issues with the seats’ heating system. I prefer to clean the plugs since it’s simpler compared to replacing them. I use vinegar, baking soda, or a cleaner capable of removing corrosion. Here are the steps to follow –
Step 1
Disconnect the car’s battery.
Step 2
You may need to unscrew and lift the seat to access the plugs better.
Step 3
Unplug the plugs and dip them into the cleaner.
Step 4
Allow the plug to remain in water for about half an hour.
Step 5
Rinse and dry, then plug them back on.
Step 6
Reconnect the car’s battery and test.
3. Wiring Issue
A broken, loose, or frayed wire in the seat heating system may also be behind this issue. The wires develop these issues during the day-to-day operations, like moving the seat forward and back.
When the wire has an issue, the current to the heating element is disrupted, and the system turns off after a few seconds.
Solution
The solution to a broken or loose wire is to reconnect it to the other end. Locate the wire, rejoin it with the other broken end, and insulate it with a shrink film or a heat shrink tube.
Wrap a frayed wire with electrical tape to prevent a short circuit with the surrounding metallic surfaces.
4. Bad Thermistor
A bad thermistor may also be behind the heated seat issue. The thermistor acts as a temperature sensor, reading the temperatures on the seat and sending the information to the module.
The thermistor can fail over time after years of heating and cooling. Also, exposure to moisture can allow corrosion to form on the connection points. However, I consider electrical issues, like voltage spikes, to be the common reasons behind a bad thermistor.
When the thermistor is faulty, it can cause the safety feature inside the car seat to disconnect too soon. The overheating protection feature disconnects the heating system when the thermistor detects high temperatures.
Solutions
Replacing the faulty thermistor will fix the issue with the heating feature turning off after a few seconds. However, this replacement involves removing the vehicle’s seat cushion or backrest. Get a professional to replace the thermistor and avoid damaging the seat during the process.
However, if you have the tools and the expertise, you can attempt the replacement. These are the steps I follow when handling this repair.
Step 1
Disconnect the battery.
Step 2
Unscrew the seat at its base.
Step 3
Disconnect the various connectors to the seat.
Step 4
Remove the seat from the car.
Step 5
Remove the cushion or backrest to access the thermistor.
Step 6
Remove the old thermistor and replace it with a new one.
Step 7
Replace the seat cushions and backrest.
Step 8
Install the seat back on the car and screw it on.
Step 9
Reconnect the battery and test the car.
This repair will cost you between $100 and $200 if handled by a mechanic.
5. Faulty Heating Element Issues
When the passenger seat doesn’t have this issue, the heating element on the driver’s side may be the cause. The heating element can become faulty after a long time of use.
When failing, these elements can interfere with heating and cause the system to turn off after seconds. To confirm the heating elements as the cause, test with new ones before connecting.
Solutions
Replace the heating elements if they are behind this issue. The steps to follow are the same as the above (changing thermistor). However, consult the user manual to learn the types of heating elements to buy.
Final Thoughts
In essence, I suggest you first use a diagnostic test tool to scan the car for issues. Afterward, go through each potential reason, starting with the easier ones. A reset to the seat module should be among the first to try, as it can fix the issue.
While most of the solutions are easy to do, others will require expertise and better knowledge of repairs. Hire a professional to handle the repairs and replacements to avoid damage to the seat or the heating system.
