P246E — Exhaust Gas Temperature Sensor Circuit

The diagnostic trouble code (DTC) P246E indicates a problem with the exhaust gas temperature (EGT) sensor circuit. This sensor plays a critical role in monitoring the temperature of exhaust gases, which helps the engine control unit (ECU) manage emissions, fuel efficiency, and after-treatment systems like the diesel particulate filter (DPF). When this code is stored, it generally means there is an anomaly in the sensor’s circuit signal, which could be caused by an electrical or mechanical fault. It’s important to remember that labels for this code may vary between different vehicle manufacturers—some may use an OEM-specific code or description.

System affected: Exhaust Gas Temperature (EGT) sensor circuit
Severity: Moderate — requires checking but not always urgent
Main symptoms: Possible engine warning light, efficiency loss, or DPF issues
Driveability: Limited — vehicle may operate normally or with restrictions depending on severity

Manufacturer variations for trouble code P246E

Different vehicle manufacturers might label or code this fault differently, but the core issue remains the same: a problem within the exhaust gas temperature sensor circuit. Here are some known label variations:

Ford: P246E – Exhaust Gas Temperature Sensor Circuit Range/Performance (Diesel Engines)
Volkswagen/Audi: P246E – Exhaust Temp Sensor Circuit Malfunction
Mercedes-Benz: P246E – Exhaust Gas Temperature Sensor Circuit Fault
BMW: P246E – Exhaust Gas Temp Sensor Circuit Signal Fault

What does trouble code P246E mean?

In straightforward terms, P246E points to a problem in the circuit wiring or the sensor itself that measures the temperature of the exhaust gases. The ECU (Engine Control Unit) constantly monitors the sensor’s voltage signals to assess whether they are within expected ranges for proper engine and emission control. When the signal is outside these expected limits—due to a wiring short, open circuit, faulty sensor, or other electrical issues—the ECU registers the P246E code. This kind of fault often appears in diesel engines that have a dedicated exhaust gas temperature sensor as part of their emissions control system.

This code is typically triggered under conditions where the ECU detects inconsistent or abnormal temperature readings, especially during engine startup, heavy load, or during regeneration cycles of after-treatment systems such as the diesel particulate filter (DPF). It is also common for this code to surface after sensor replacement or electrical repairs if proper procedures are not followed.

Severity and risks of trouble code P246E

This trouble code indicates a moderate level of concern. If ignored, the vehicle could experience increased emissions, reduced fuel economy, or issues related to exhaust after-treatment performance. In some cases, the engine’s management system may go into a limited operation mode to protect essential systems. Further, if the fault stems from a failing sensor or wiring issue, continued operation without repair could lead to damage to the sensor, wiring harness, or other related components.

In general, the vehicle can often be driven with this code present, but it is not advisable to ignore it for long periods. Persistent faults might lead to engine derate or increased emissions, which could cause failure during emissions testing or inspections.

Symptoms of trouble code P246E

Recognising the symptoms can help in initial diagnostics. Common signs include:

Illuminated engine warning light (Check Engine Light)
Poor fuel economy or reduced engine performance
Frequent regeneration cycles or DPF-related alarms
Erratic or abnormal exhaust temperatures indicated in live data (if accessible)
Possible increased emissions or smell of unburned fuel
Engine warning lights triggered after cold starts or during highway driving

Most likely causes of trouble code P246E

This fault typically originates from issues related to the exhaust gas temperature sensor circuit. Below are the most common causes, ranked from most to least probable:

Faulty or damaged exhaust gas temperature (EGT) sensor: The sensor itself may have failed due to age, heat, or contamination.
Wiring or connector problems: Corrosion, broken wires, or poor connections can disrupt the sensor’s signal.
Electrical short circuit or open circuit: A wiring fault that causes the signal to be outside expected parameters.
Sensor installation issues: Incorrect mounting or wiring during recent repairs or replacements.
ECU software or calibration issues: Rare but possible if the ECU’s firmware is outdated or corrupted.

How to diagnose trouble code P246E

Diagnosing this code requires a methodical approach to identify whether the issue lies with the sensor itself, its wiring, or the ECU. Here are generic steps suitable for most vehicles:

Visual inspection: Check the wiring harness and connectors for damage, corrosion, or loose connections near the exhaust and sensor location.
Verify sensor installation: Ensure the sensor is installed properly and securely in its mounting point.
Check live data: Using an OBD-II scanner or diagnostic tool, monitor the exhaust gas temperature sensor readings during engine operation. Ensure values are within expected ranges.
Inspect wiring continuity: Perform a continuity test on the sensor wiring to rule out breaks or shorts in the lines.
Test sensor resistance: Measure the sensor’s resistance with a multimeter according to the manufacturer’s specifications if available.
Clear codes and test drive: After repairs, clear all DTCs and perform a test drive to see if the code returns and if sensor readings behave normally.

Possible repairs for trouble code P246E

The appropriate repair depends on the identified cause. Solutions range from simple to complex and often require professional intervention.

Replace the faulty exhaust gas temperature sensor: The most common fix if the sensor is proven to be defective. (Basic repair, DIY feasible with proper tools)
Repair or replace wiring and connectors: Fix corroded or broken wiring, clean or secure the electrical connections. (Basic to intermediate repair, professional recommended if in doubt)
Correct installation issues: Reinstall or rewire the sensor correctly after improper installation.
Update ECU firmware: In rare cases, a software update from the OEM may resolve sensor communication issues.
Replace associated components: If the after-treatment control module or related components are faulty, those may need replacement under professional supervision.

Vehicles commonly associated with trouble code P246E in Europe

This code is often found in diesel vehicles equipped with exhaust gas temperature sensors for emissions or DPF management. Typical brands and engine families include:

Volkswagen Group: TDI engines (e.g., 2.0, 2.5 TDI)

Mercedes-Benz: OM651, OM654 diesel engines

Peugeot/Citroën: BlueHDi diesel engines

BMW: N47 and B37 diesel engine series

Ford: Duratorq TDCi engines

Frequent mistakes with trouble code P246E

Diagnosing and repairing this fault requires care; common errors can lead to missed or unnecessary repairs. These mistakes include:

Ignoring visual damage to wiring or connectors without inspection
Replacing the sensor without testing: Assuming the sensor is faulty without verifying it can lead to unnecessary costs.
Overlooking simple wiring issues: Often, wiring problems are the root cause but are neglected in favour of more complex parts.
Not clearing the code after repairs: Failing to clear DTCs can lead to confusion during subsequent diagnostics.
Assuming ECU fault prematurely: The ECU is rarely at fault; most issues are electrical or sensor-related.

FAQ — trouble code P246E

Can this code disappear on its own?
Generally, no. This fault persists until the underlying issue is diagnosed and repaired. Temporary glitches or electrical interference might cause brief false readings, but persistent codes require a thorough check.

Can I keep driving?
In most cases, yes, but it is not advisable to ignore the problem long-term. Driving with this code might cause increased emissions or degrade DPF performance. If the engine warning light is on or if symptoms worsen, it’s better to have it checked soon.

Why does the code return after clearing?
If the root cause—such as a damaged wiring, a faulty sensor, or poor connections—is not addressed, the code will likely reappear after reset. This indicates an ongoing problem that needs correction.