Code Definition

B2428 — A/C Post Heater Sensor #2 Circuit Failure

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B2428

B2428 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B2428 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B2428 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Climate Control Module uses the A/C Post Heater Sensor #2, an NTC thermistor mounted in the air flow path immediately downstream of the heater core, to monitor actual conditioned air outlet temperature for closed loop temperature control. DTC B2428 is set when the module detects a circuit failure on the post heater sensor #2 input, meaning the signal voltage is outside the rational range for any plausible air temperature, typically pegged at the supply rail indicating an open or pulled to ground indicating a short. The failure may be caused by a faulty sensor, a wiring fault, or a damaged ...

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