P2479

Code

Generic P — Powertrain

Exhaust Gas Temperature Out of Range Bank 1 Sensor 2

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 45 RU: 24

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Faulty EGT sensor (Bank 1 Sensor 2) — open, shorted, or out of calibration
Damaged wiring harness or poor connector continuity (open, short to ground or battery, high resistance)
Corroded or contaminated connector pins
Exhaust leak upstream of the sensor or damaged exhaust hardware allowing abnormal temperatures
Clogged, melted, or damaged catalytic converter or diesel particulate filter causing abnormal exhaust temps
Sensor contaminated with soot, oil or deposits affecting measurement

Retrieve freeze frame and live data with a scan tool; record EGT values and related sensors (upstream EGT, boost, fuel trim, exhaust pressure)
Inspect EGT sensor and wiring harness for damage, chafing, corrosion, melting, or soot buildup
Check connector pins for corrosion, bent pins, or poor mating; backprobe connector to monitor signal where applicable
Measure sensor circuit resistance/voltage per manufacturer procedure (or compare to a known-good sensor)
Check for exhaust leaks and physical damage to exhaust, catalytic converter or DPF upstream of the sensor
Verify grounds and power feeds to ECM and sensor circuits

Typical downstream EGT operating range: approximately 200°C to 800°C during normal operation (varies by engine and load). Consult service manual for exact values.
Thermocouple sensors produce a small millivolt (mV) output proportional to temperature; some systems condition the signal to a 0–5 V scale — check vehicle-specific spec.
Open-circuit indication: sensor circuit shows very high resistance or no mV/voltage (out of range low)
Short-to-ground or short-to-battery: circuit resistance near 0 Ω or fixed voltage near 0 V or battery voltage depending on sensor type
Response behavior: EGT should rise and fall with engine load; a sensor that does not respond or lags significantly may be failing

Connect a capable scan tool, read freeze frame and live EGT values, and confirm the code is current. Note other related codes (O2, boost, catalyst).
Visually inspect Bank 1 Sensor 2 and wiring harness for obvious damage, heat exposure, soot/contamination, or loose connectors.
With ignition off, disconnect the sensor connector and check for corrosion, bent pins, and secure mating. Reconnect and wiggle-test while monitoring for intermittent changes.
Measure sensor circuit continuity to the ECU and check for shorts to ground or battery. Repair any wiring faults found.
Measure sensor output per service manual (thermocouple mV or conditioned voltage) at known temperature or compare to an identical sensor if available. Replace sensor if out of spec.
Inspect exhaust system upstream of the sensor (manifold, catalytic converter, DPF) for damage, restrictions, leaks, or signs of overheating that could cause abnormal temps.
If wiring and sensor check good but reading still out of range, swap with a known-good same-type sensor (if practical) or substitute with bench-tested sensor to confirm sensor vs. ECU.
If sensor and wiring test OK and problem persists, consider PCM/ECM diagnostics or software update per manufacturer procedures.
After repairs, clear codes and perform a road test while monitoring EGT values to confirm proper operation and that the code does not return.