What does it mean?
B2181 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Heated Seat Module Power Supply Low .
Symptoms
- Wipers stay in one speed and will not switch off
- Intermittent or delay mode no longer available
- Wipers start on their own when the ignition is turned on
- Wipers refuse to park correctly at the end of a sweep
- Other stalk functions such as washer or lights may also misbehave if the switch is water damaged
- Warning message about the wiper system
Likely causes
- Multifunction stalk switch with contacts stuck closed or carbon tracked between positions
- Water running down the steering column into the switch assembly
- Signal wire chafed against the column bracket or a metal edge behind the dash
- Corroded terminals in the stalk connector after damp or a windscreen leak
- Loose or damaged clockspring area wiring where the loom flexes with column adjustment
- Aftermarket accessory spliced into the wiper circuit
- Poor module ground making a normal input read as a ground
- Body module input failure, only after the switch and harness are proven
How to fix it
- Confirm the manufacturer definition and which pin carries the select switch C input
- Watch the wiper switch position in live data with the stalk at rest, a permanently active state confirms the fault is present
- Disconnect the stalk switch and see whether the input clears
- With the switch disconnected, measure the input circuit resistance to ground, it should read open
- Ohm the switch itself through each detent and compare with the specified values
- Inspect the column loom for chafing and the connector for water and green corrosion
- Verify module supply and ground quality
- Replace the stalk switch or repair the harness, then test every wiper mode and confirm correct park behaviour