P2472

Code

Generic P — Powertrain

Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 1 Sensor 4

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 81 RU: 32

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Page language: EN

Causes

Damaged, corroded or loose connector at the EGT sensor
Broken, chafed, or shorted wiring harness to the sensor
Contaminated, thermally damaged or failed EGT sensor
Poor or missing ground or supply to the sensor/heater (if equipped)
Exhaust leaks or physical damage near the sensor affecting readings
Intermittent ECM input or internal ECM fault (less common)

Symptoms

Check Engine Light (MIL) illuminated intermittently
Stored P2472 freeze frame and/or intermittent DTC
Possible reduced performance or forced regeneration issues (diesel vehicles)
Failed emissions test or increased exhaust smoke/odors
Occasional loss of sensor data on scan tool or erratic temperature readings

What to check

Read freeze frame and live data with a scan tool; note when code sets and what sensor readings show
Visually inspect sensor, connector and wiring for burns, melting, corrosion, pin damage, or chafing
Wiggle test harness and connector while monitoring live EGT signal for intermittent changes
Check continuity and resistance of sensor heater circuit (if equipped) and signal/ground to ECM
Check for exhaust leaks near the sensor and confirm proper sensor mounting torque/position
Inspect ECM connector pins related to the EGT sensor for corrosion or looseness

Signal parameters

Sensor type varies by vehicle (thermocouple or RTD); expected behavior: smooth, monotonic rise in output with exhaust temperature, not sudden spikes or dropouts
No open circuit: continuity from sensor signal to ECM pin should be present; no short to voltage or ground
Heater circuit (if present): proper supply voltage on key-on/run and reasonable resistance per manufacturer spec
Live-data: signal should not jump to extreme values (open circuit or short) and should respond to engine load quickly and smoothly

Diagnostic algorithm

Retrieve freeze frame and full DTC history. Note conditions (engine temp, load, ambient) when the code stored.
Visually inspect Bank 1 Sensor 4 sensor, connector and harness for heat damage, pin corrosion, disconnection, or physical damage.
Backprobe the signal, ground and heater (if present) with a scan tool/DT instrument while monitoring live EGT data. Perform a wiggle test on the harness and connector to reproduce intermittent behavior.
Check continuity between the sensor signal pin and the ECM pin with ignition off. Check for shorts to battery voltage and ground.
Measure sensor output type-appropriate: for thermocouples monitor millivolt output vs temperature change; for RTD measure resistance vs temperature (use service spec if available). Verify heater supply voltage and heater resistance if applicable.
Inspect and repair any wiring damage, connector faults or poor grounds. Replace damaged clips, loom, or heat shields that allow harness contact with hot/exposed surfaces.
If wiring and connector check OK but the signal is still erratic, swap with a known-good sensor (if practical) or bench-test/replace the suspect sensor.
After repair or replacement, clear codes and road-test under similar conditions to those in the freeze frame. Verify the code does not return and that EGT data is stable.
If problems persist after sensor and wiring verification, test the ECM input for proper operation or consult manufacturer procedures for ECM diagnosis.

Likely causes

Wiring harness chafed by heat or contact with moving parts (most common)
Connector corrosion or water ingress causing intermittent contact
Failed EGT sensor due to thermal cycling or contamination
Loose sensor mounting or mounting stud threads damaged
High-resistance ground or power circuit to sensor
ECM input circuit intermittent (rare)

Fault status

⚠️ Status

Intermittent or erratic signal detected from Exhaust Gas Temperature Sensor Circuit — Bank 1 Sensor 4. ECM has logged unstable/out-of-range readings requiring inspection of sensor, wiring, connectors and related circuits.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours