B2381
Severity: LowHeater Coolant Temp sensor circuit Open
Last updated: July 2026
System
Body
Subsystem
Body Electronics
Code Type
Manufacturer-specific
Heater Coolant Temp sensor circuit Open
Last updated: July 2026
B2381 is a manufacturer-specific body diagnostic trouble code. It is defined as "Heater Coolant Temp sensor circuit Open". It falls under the body electronics area of the vehicle’s body system, and its exact meaning can vary between manufacturers.
The onboard diagnostic system sets B2381 when it detects a condition matching "heater coolant temp sensor circuit open" in the body electronics circuit or system. When the fault is confirmed, the module stores the code and, in most cases, turns on a warning light.
This code is generally minor and often relates to a signal, range or performance condition. It should still be inspected, especially if it returns after clearing.
B2381 means "Heater Coolant Temp sensor circuit Open". It is a manufacturer-specific body trouble code in the body electronics area.
This code is usually minor, and short-distance driving is often possible, but you should still have it checked — especially if the warning light stays on or the code returns.
There is no single fix. Start by confirming the code with a scan tool, then work through the likely causes and checks above — inspecting wiring, connectors and the relevant components before replacing any parts. On your specific make, confirm the diagnosis before repairs.
You can clear the code with an OBD-II scan tool, but if the underlying fault is still present it will usually return. Clearing without repair is only useful to confirm whether the fault is active.
This information is provided for general reference only. It is not repair advice and may not apply to every make or model. Manufacturer-specific codes can differ. Always confirm a diagnosis with a scan tool and, where needed, a qualified technician before replacing parts.