B2466

Caution

Aux Heater Overheat Counter Overrun/System Locked

Severity
Caution
Category
Body
Code Type
Generic OBD-II
Applicable Regions
US, EU, Global

Is it safe to drive?

๐Ÿ”ต Do not use this page as drive-clearance. Monitor the alert and arrange service if it returns.

What does B2466 mean?

B-code B2466 means "Aux Heater Overheat Counter Overrun/System Locked". It is a generic OBD-II diagnostic trouble code (DTC) in the body electronics. An abnormal temperature condition has been detected in the aux heater overheat counter overrun/system locked โ€” the system may be overheating or running too cold. This code can be monitored, but service is recommended to prevent escalation. This code applies to OBD-II compliant electric and hybrid vehicles.

Possible Causes

  • Cooling system failure (low coolant, blocked radiator, or pump failure)
  • Ambient temperature extremes affecting sensor calibration
  • Faulty temperature sensor providing inaccurate readings
  • Thermal management system component failure

Recommended Actions

  1. 1 Note the alert and schedule a diagnostic appointment when convenient
  2. 2 Scan for all DTCs with an OBD-II scanner โ€” note any related codes stored alongside B2466
  3. 3 Check coolant level, coolant flow, and cooling fan operation
  4. 4 Inspect the temperature sensor and its wiring for damage or corrosion
  5. 5 Clear the DTC, road-test the vehicle, and re-scan to confirm whether the fault returns
  6. 6 If the fault persists after inspection and clearing, consult an EV-certified technician for component replacement

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