B2922

Code

Generic B — Body

Passenger compartment temperature sensor circuit malfunction

Brand: Generic

Type: B — Body

Views: UK: 16 EN: 18 RU: 15

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or short in sensor wiring harness (broken wire, chafing, pinched)
Corroded, loose or damaged sensor connector or terminals
Failed passenger compartment temperature sensor (thermistor/NTC/PTC)
Water intrusion or contamination at sensor or connector
Failed HVAC control module / body control module input circuit
Incorrect replacement sensor (wrong resistance curve) or aftermarket component

Symptoms

Incorrect cabin temperature readout or unstable readings
Automatic climate control not maintaining set temperature
HVAC system cycling or running at incorrect blower/blend settings
DTC B2922 stored and possibly other HVAC-related codes
Sometimes a message or warning related to climate control

What to check

Scan tool: read DTC(s), freeze frame, and live cabin temperature sensor value(s)
Identify sensor location (passenger compartment / inside dash near evaporator or glovebox)
Visual inspection of sensor, connector, and wiring for damage, corrosion, or water ingress
Wiggle harness while monitoring live sensor value to reproduce intermittent faults
Check fuse(s) related to HVAC/control module if applicable
Confirm correct replacement sensor if recently serviced

Signal parameters

Sensor type: commonly NTC thermistor (negative temperature coefficient) — resistance decreases as temperature rises
Typical signal: 0–5 V analog voltage to HVAC/BCM (varies by design). Cold ≈ higher voltage or resistance depending on circuit; hot ≈ lower voltage/resistance.
Example typical thermistor resistance (manufacturer-specific): ~10 kΩ at 25 °C (use service data).
Expected behavior: smooth, monotonic change in resistance or voltage with temperature changes; no open (> OL) or short (~0 Ω) conditions.
If backprobing at ECU: expected continuity to sensor ground and proper pull-up/pull-down voltages per vehicle spec

Diagnostic algorithm

Use a scan tool to confirm B2922 is current or stored; note freeze frame and live passenger temp sensor reading. Check for related HVAC/BCM codes.
Locate passenger compartment temperature sensor (consult service manual for exact position). Perform visual inspection for contamination, water, or obvious damage.
With ignition ON, monitor live sensor value while warming/cooling sensor (use a bag of ice or warm air). Value should change smoothly. If value stuck or erratic, suspect wiring or sensor.
Backprobe the sensor connector with a multimeter: measure signal voltage and reference/ground. Compare to expected 0–5 V range and to other cabin sensor (if present).
With sensor disconnected, measure sensor element resistance across its terminals and compare to ambient-temperature specification (service data). For NTC, resistance should decrease when warmed by hand.
Check wiring continuity between sensor connector and HVAC/BCM connector. Check for shorts to ground or battery voltage. Repair any damaged wiring or connectors.
Wiggle test: with connector/terminals connected, wiggle harness and connector while watching live data for intermittent changes. Repair harness clamps or reroute to prevent chafing.
If wiring and connector are good but sensor out of spec, replace sensor with OEM or exact spec part. Re-test live data and operation.
If replaced sensor and good wiring but code persists, perform module input circuit tests per manufacturer procedures; consider module replacement only after verifying wiring and sensor integrity.
Clear codes and perform a functional test/road or cabin temperature stabilization test to confirm proper operation over temperature range.