Faulty EGR temperature sensor with an internal short or drifted reading; Signal wire chafed and shorted to ground or to another ground-referenced wire; Damaged, corroded or water-contaminated connector or terminals at the sensor; Sensor reference or ground wiring fault causing an incorrect low reading; Faulty EGR cooler or valve assembly with an integrated sensor that has failed; Fault inside the engine control unit's sensor input circuit.

P04E7

EGR Temperature Sensor D Circuit Low.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
4: AreaAuxiliary emission controls
E7: FaultThe specific fault in that area

What it means

P04E7 is a generic powertrain code meaning the engine control unit has seen a low signal from the EGR temperature sensor 'D' circuit. The voltage or signal is below the expected range, which points to a short to ground, a faulty sensor or a wiring fault. Which sensor is 'D' and where it sits depends on the engine and model, so check the manufacturer's information.

Symptoms

Engine warning light on
Possible reduced performance or limp mode on some models
Rough idle or hesitation if EGR operation is restricted
Slightly higher fuel consumption
Other EGR-related codes stored alongside it
Failed emissions test

Possible causes

Faulty EGR temperature sensor with an internal short or drifted readinglikely
Signal wire chafed and shorted to ground or to another ground-referenced wirelikely
Damaged, corroded or water-contaminated connector or terminals at the sensorlikely
Sensor reference or ground wiring fault causing an incorrect low readingpossible
Faulty EGR cooler or valve assembly with an integrated sensor that has failedpossible
Fault inside the engine control unit's sensor input circuitrare

How to diagnose

Read all stored codes and freeze frame data to see engine temperature, load and speed when the fault set, and note any other EGR or sensor supply codes.
Check for technical service bulletins and the manufacturer's definition of sensor 'D' for this engine.
Inspect the sensor, its connector and the wiring harness for heat damage, chafing, oil contamination, corrosion and water ingress.
With the engine cold, compare the live EGR temperature reading with the coolant and intake air temperatures; they should be broadly similar.
Unplug the sensor and check the live data and circuit voltage; if the fault changes to a circuit high or open code, the wiring to the sensor is likely sound and the sensor is suspect.
Test the sensor resistance against the manufacturer's specification at a known temperature.
Check the signal wire for a short to ground and for continuity back to the control unit, with the battery disconnected and the control unit unplugged as per the manufacturer's procedure.
Check the sensor supply and ground against specification before suspecting the control unit.

How to fix

Replace the EGR temperature sensor if its readings or resistance are out of specification.
Repair or replace damaged wiring and renew faulty terminals or connectors.
Clean and properly seal the connector, and fix the cause of any water or oil contamination.
Replace the EGR cooler, valve or sensor assembly if the sensor is not available separately and has failed.
Clear the code after repair and road test to confirm it does not return, and only consider the control unit after all other causes are ruled out.

Can I keep driving?

Low severity

The car can usually be driven short term, but book it in soon. If it goes into limp mode, runs poorly or other warnings appear, limit driving until it is checked.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.