Faulty EGR temperature sensor C (internal open or short circuit, or contamination with soot); Damaged, chafed or heat-affected wiring between the sensor and the control module; Corroded, loose or contaminated connector terminals at the sensor or control module; Short to voltage or earth in the sensor signal or reference circuit; Poor sensor earth or low reference voltage supply from the control module; Heavy carbon build-up in the EGR system affecting sensor readings, or a stuck EGR valve or cooler fault; Faulty powertrain control module.

P04CE

EGR Temperature Sensor C Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

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

What it means

P04CE is a generic code meaning the powertrain control module has detected a fault in the circuit of exhaust gas recirculation (EGR) temperature sensor 'C'. The module monitors the sensor's signal voltage and sets the code when it is outside the expected range or does not behave plausibly. Which sensor is 'C', and its position in the EGR system, depends on the vehicle and engine, so check the manufacturer's information.

Symptoms

Engine management light on
Rough idle or hesitation in some conditions
Reduced performance or limp mode on some vehicles
Slightly higher fuel consumption
Failed emissions test
Other EGR-related codes stored alongside it

Possible causes

Faulty EGR temperature sensor C (internal open or short circuit, or contamination with soot)likely
Damaged, chafed or heat-affected wiring between the sensor and the control modulelikely
Corroded, loose or contaminated connector terminals at the sensor or control modulelikely
Short to voltage or earth in the sensor signal or reference circuitpossible
Poor sensor earth or low reference voltage supply from the control modulepossible
Heavy carbon build-up in the EGR system affecting sensor readings, or a stuck EGR valve or cooler faultpossible
Faulty powertrain control modulerare

How to diagnose

Read all stored and pending codes and note any other EGR, air flow or temperature sensor codes, then review the freeze frame data.
Check for relevant technical service bulletins and confirm which sensor is 'C' and where it is fitted on this model and engine.
Visually inspect the sensor, its wiring and the connector for heat damage, chafing, corrosion, water ingress or loose pins.
With the engine cold, compare the live EGR temperature sensor reading with other temperature sensors such as coolant and intake air; they should be similar.
Watch the live data as the engine warms up and the EGR operates, checking for a smooth, plausible change rather than a fixed, jumping or out-of-range value.
With the ignition off and the connector unplugged, check the sensor resistance against the manufacturer's specification and test the wiring for continuity and shorts to earth or voltage.
Check the reference voltage and earth at the sensor connector with the ignition on.
Inspect the EGR valve, cooler and pipework for heavy soot build-up or blockage if the wiring and sensor test fine.

How to fix

Replace the EGR temperature sensor C if its resistance or signal is out of specification.
Repair or replace damaged wiring and fix any short or open circuit found.
Clean, repair or replace corroded or loose connector terminals and secure the harness away from heat sources.
Clean or replace a heavily sooted or faulty EGR valve or cooler as the manufacturer advises.
Replace or reprogram the control module only after all other causes are excluded and the manufacturer confirms a module fault.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but book it in soon because the EGR system may not work properly, which can affect emissions, performance and economy. If the car goes into limp mode or runs badly, limit driving until it is checked.

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