B2914

Code

Generic B — Body

Outside Ambient Temperature Sensor Circuit Fault

Brand: Generic

Type: B — Body

Views: UK: 18 EN: 24 RU: 19

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Use a scan tool to read freeze-frame and live OAT value; check whether value is static, out-of-range, or intermittent
Visually inspect sensor location (usually front bumper/behind grille), connector, and wiring for damage or corrosion
Check for trouble codes stored in body/climate and related modules
Probe connector with multimeter: measure sensor resistance (with sensor disconnected) and voltage (key ON) at the harness/connector
Check continuity between sensor connector and control module connector; check for short to ground or battery
Wiggle harness and sensor while monitoring live data to identify intermittent faults

Typical sensor type: NTC thermistor (negative-temperature-coefficient)
Approx. resistance (examples for a common 10 kΩ @25°C NTC): -40°C: >100 kΩ (very high), 0°C: ~30–40 kΩ, 25°C: ~8–12 kΩ, 40°C: ~4–6 kΩ (values vary by sensor)
Expected voltage at sensor circuit (with typical pull-up): roughly 0.3–4.7 V across ambient temperature range (exact values depend on vehicle pull-up resistor and module reference voltage)
Open circuit: resistance = infinite or very high; short to ground: voltage ≈ 0 V; short to battery/pull-up: voltage ≈ reference (often 5 V)

Read and record freeze-frame data and current live OAT readings with a scan tool. Note related codes in other modules.
Inspect sensor location and connector for physical damage, contamination, or water ingress. Replace or clean if corroded.
With ignition ON (engine off), backprobe sensor connector harness side: measure voltage between signal and ground. Compare to expected range. If signal ~0 V or ~reference voltage, proceed to step 5.
Remove sensor and measure resistance across sensor terminals at ambient temperature. Compare to manufacturer specification or typical NTC values (e.g., ~10 kΩ at 25°C). If sensor out-of-spec, replace sensor.
If sensor resistance is good but harness signal abnormal, perform continuity check between sensor connector and module connector; check for short to ground and short to battery. Repair any wiring faults.
If wiring and sensor test good but code persists, inspect module grounds and power supplies. Repair any poor grounds or power issues.
If harness, sensor, and module power/grounds are confirmed good, consider replacing the body/climate control module or consult manufacturer technical service bulletins.
After repair, clear codes and verify correct OAT readings and system operation over a test drive and by comparing to an independent thermometer. Re-check for reappearance of code.