Code
P2471
Generic
P — Powertrain
Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 4
Views:
UK: 23
EN: 79
RU: 26
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in EGT sensor circuit (short to battery/ignition voltage)
- Poor or corroded connector or pin (intermittent/high-voltage reading)
- Failed EGT sensor (resistive thermistor or thermocouple type)
- Damaged sensor harness from heat, chafing, or soot contamination
- Aftertreatment/DPF removal or damage causing sensor exposure/contamination
- Faulty ECM or poor ECM sensor reference/ground (less common)
Symptoms
- Check Engine MIL illuminated
- Reduced engine performance or forced derate on some vehicles
- DPF or SCR regeneration faults or unavailable regen attempts
- Possible increased fuel consumption or rough running during regeneration
- Stored EGT-related trouble codes, possible limp-home behavior
What to check
- Read freeze-frame and live data with a scan tool; note EGT sensor voltage/temperature and stored status flags
- Visual inspection of sensor, connector, and wiring for corrosion, heat damage, soot, or chafing
- Wiggle test wiring while monitoring live data for intermittent changes
- Backprobe connector and measure signal voltage or mV output with key on/engine running as specified
- Measure resistance of sensor (if resistive type) cold and compare to specification, or measure thermocouple mV output when hot
- Check power supply and ground circuits to ECM for proper reference voltages and continuity
Signal parameters
- Typical resistive EGT sensors: vehicle supply/common reference 0–5.0 V signal range; 'high' faults often registered above ~4.5 V (varies by make)
- Typical thermocouple EGT sensors: low millivolt output proportional to temperature; a fixed high-voltage-like reading can indicate short to B+ or open circuit
- Sensor resistance at 20°C: depends on part (example ranges 1k–10kΩ for some thermistors) — consult vehicle-specific chart
- Heater circuit (if equipped): expected current draw and resistance values shown in service manual; open or shorted heater element can set faults
Diagnostic algorithm
- Connect a scan tool, confirm P2471 is current or stored, record freeze frame and live EGT sensor values for Bank 1 Sensor 4.
- Visually inspect the sensor, connector, and wiring harness from sensor to ECM for damage, corrosion, soot, melted insulation, or signs of overheating.
- With connector disconnected, check connector pins for corrosion, bent pins, or pushed-out terminals. Repair as needed.
- Backprobe the sensor connector and measure signal voltage (or mV for thermocouple) with key on/engine running per service data. Compare to expected range; note if signal reads very high or near battery voltage.
- Check continuity and resistance of wiring between the sensor connector and the ECM pin. Look for short to battery (B+) or to ground using an ohmmeter; repair any faults.
- If the sensor is resistive: measure sensor resistance at ambient and after controlled heating if possible; compare to spec. If thermocouple: check mV output when hot. Replace sensor if values are out of spec.
- If sensor heater is present, measure heater resistance and supply voltage; verify heater control/ground operation via scan tool and bench checks.
- Repair or replace damaged wiring/connector or replace the EGT sensor. Clear codes and perform an operational test/road test while monitoring live data to confirm the fault does not return.
- If wiring and sensor test good but code persists, inspect ECM grounds and power supplies. If all else fails, consider ECM failure and consult manufacturer technical resources before ECM replacement.
Likely causes
- Connector corrosion or pin pushed out at sensor or ECM
- Open circuit or short to B+ in the sensor wiring near the sensor
- Defective/contaminated EGT sensor element
- Heat-damaged wiring or insulation causing intermittent shorts
- Aftertreatment hardware problem exposing sensor to excessive exhaust or contaminants
Fault status
Status
Exhaust Gas Temperature Sensor Circuit High - Bank 1 Sensor 4
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
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