P246E — Exhaust Gas Temperature Sensor Circuit #
Note: The exact wording of this code’s description may vary by vehicle manufacturer (OEM). Below are some known variations:
- Exhaust Gas Temperature Sensor Circuit (General, SAE Standard)
- Exhaust Gas Temperature Sensor Circuit Malfunction (Ford, GM, Volkswagen, Mercedes-Benz)
- EGT Sensor Circuit Fault (Toyota, Nissan)
Code Summary for P246E #
The P246E diagnostic trouble code (DTC) indicates a detected issue with the circuit connected to the Exhaust Gas Temperature (EGT) sensor. The EGT sensor is a critical component in the vehicle’s emissions system, monitoring the temperature of exhaust gases to keep the diesel particulate filter (DPF) and other components operating safely and efficiently. When the engine control module (ECM) or powertrain control module (PCM) detects an abnormal voltage or signal from this sensor’s circuit, it triggers the P246E code. This can affect emissions, engine performance, and the longevity of emission control parts. Addressing this code promptly is important to maintain proper engine operation and avoid further complications.
Common Symptoms for Code P246E #
A malfunction in the exhaust gas temperature sensor circuit can produce a range of symptoms, some subtle and others more obvious. Drivers or technicians might notice the following:
- Illuminated Check Engine Light
- Reduced engine power (limp mode)
- Increased exhaust emissions or smoke
- Poor fuel economy
- DPF regeneration issues or warnings
- Abnormal engine temperature readings
Probable Causes for Code P246E #
The causes behind a P246E code can vary, but some are more common than others. Understanding the likely culprits helps streamline diagnostics and repairs:
- Faulty exhaust gas temperature sensor (sensor failure or internal short/open)
- Damaged or corroded sensor wiring/connectors (broken wires, poor connections, water ingress)
- Short or open circuit in the EGT sensor circuit
- Faulty ECM/PCM (rare, but possible if all other causes are ruled out)
- Aftermarket modifications affecting sensor operation
Step-by-Step Diagnostic for Code P246E #
Diagnosing a P246E code requires a systematic approach, ensuring all potential problems are checked and confirmed. Here’s a step-by-step guide:
- 1. Read and record all active and pending codes using a scan tool. Clear codes and see if P246E returns.
- 2. Visually inspect the exhaust gas temperature sensor and wiring for obvious damage, corrosion, or loose connectors.
- 3. Check for proper voltage and ground at the EGT sensor connector with a digital multimeter.
- 4. Test the sensor’s resistance and compare it to OEM specifications (refer to service manual).
- 5. Inspect the wiring harness from the sensor to the ECM/PCM for continuity and shorts.
- 6. Substitute with a known-good EGT sensor if available to see if the problem resolves.
- 7. If all else passes, consider ECM/PCM testing or reprogramming (rare, but may be necessary).
Possible Repairs for Code P246E #
Repairing a P246E code depends on the specific cause diagnosed. Common solutions include:
- Replacing a faulty exhaust gas temperature sensor
- Repairing or replacing damaged wiring or connectors
- Cleaning corroded connections and applying dielectric grease
- Repairing shorts or open circuits in the wiring harness
- Reprogramming or replacing ECM/PCM (rare and only after other solutions are exhausted)
Is It Safe to Drive with Code P246E? #
Driving with code P246E is not recommended for extended periods. While the vehicle may still operate, a malfunctioning EGT sensor can cause improper DPF regeneration, increased emissions, and potential engine or exhaust system damage. In some cases, the vehicle may enter limp mode to protect itself, reducing power drastically. Address the code as soon as possible to prevent more serious issues and to comply with emissions regulations.
Vehicles Most Commonly Affected by P246E #
This code is more prevalent on diesel vehicles equipped with DPFs and advanced emissions controls. The following vehicle types see P246E most often:
- Ford diesel trucks and vans (Super Duty, Transit, F-Series)
- General Motors diesel models (Chevrolet Silverado, GMC Sierra Duramax)
- Mercedes-Benz Sprinter and other diesel-equipped models
- Volkswagen TDI vehicles
- Toyota and Nissan diesel trucks (in markets where applicable)
Common Mistakes and Best Practices for Code P246E #
Misdiagnosing this code or taking shortcuts can lead to recurring issues. Here’s what to watch out for:
- Replacing the sensor without checking wiring or connectors
- Ignoring related codes that may point to a wiring or control module issue
- Not verifying sensor resistance against OEM specs
- Overlooking signs of water intrusion or corrosion in connectors
- Clearing codes without performing a proper repair
Quick FAQ for Code P246E #
Q: Can a bad EGT sensor cause other codes?
A: Yes. A faulty EGT sensor can cause additional emission-related codes, especially those affecting the DPF or SCR (Selective Catalytic Reduction) system.
Q: Will my vehicle fail emissions testing with P246E?
A: Most likely, yes. An active emission sensor fault will generally trigger a failed test until the problem is repaired and the code cleared.
