P246A — Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic #

Note: The wording of this DTC (Diagnostic Trouble Code) may vary depending on the vehicle manufacturer.

• Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic (General/SAE)
• Exhaust Gas Temperature Sensor Bank 1 Intermittent Signal (Ford)
• EGT Sensor Circuit Intermittent (GM/Chevrolet)
• Exhaust Temp Sensor Signal Fault (Volkswagen/Audi)
• Exhaust Gas Temperature Sensor Circuit Range/Performance (Toyota)

Summary of DTC P246A #

The P246A trouble code indicates that the vehicle’s Exhaust Gas Temperature (EGT) sensor circuit is experiencing intermittent or erratic signals. The EGT sensor is responsible for measuring the temperature of the exhaust gases, a critical function for monitoring emissions and protecting components like the Diesel Particulate Filter (DPF) and turbocharger. When the Engine Control Module (ECM) detects irregularities in the sensor’s signal, it sets this code. This issue can lead to incorrect emissions control and may trigger a Check Engine Light. If left unresolved, it could result in reduced engine performance or even damage to the exhaust aftertreatment system.

Frequent Symptoms for DTC P246A #

A vehicle with a P246A code may present a range of symptoms, depending on the severity and frequency of the sensor’s signal faults. In some cases, symptoms can be subtle, while in others they may affect drivability or emissions.

• Illuminated Check Engine Light (CEL or MIL)
• Engine may enter “limp” or reduced power mode
• Noticeable drop in fuel economy
• Hard starting or rough idle, especially when cold
• Regeneration cycles for the DPF may not initiate or complete correctly (in diesel vehicles)
• Increased exhaust smoke or odor (in rare cases)

Probable Causes for DTC P246A #

Most causes of a P246A code are related to electrical issues or sensor faults, but wiring and connector problems are also common. Here’s what you should check, in order of likelihood:

1. Faulty exhaust gas temperature sensor (sensor itself has failed or is unreliable)
2. Wiring harness problems (damaged, corroded, or loose wires/connectors to the EGT sensor)
3. Exhaust leaks near the sensor (can cause erratic readings due to incorrect flow or temperature)
4. Connector contamination (dirt, water, or corrosion inside the sensor’s connector)
5. ECM/PCM fault (rare, but possible if all else checks out)

Step-by-Step Diagnostic for P246A #

Diagnosing a P246A code requires a logical approach. Use an OBD-II scan tool and a multimeter to follow these steps:

1. Confirm code and freeze frame data: Read the code with a scan tool and note the conditions under which it was set.
2. Inspect the EGT sensor and wiring visually: Look for broken, frayed, or burnt wires and damaged connectors along the exhaust system.
3. Check for exhaust leaks: Listen and feel for leaks near the sensor location, which can affect readings.
4. Test sensor resistance: With the sensor disconnected and engine cold, use a multimeter to compare resistance with OEM specifications.
5. Wiggle test: With the engine running and scan tool connected, gently move the harness and connector to see if the readings become erratic or the code resets.
6. Check sensor signal with live data: Monitor EGT sensor readings on the scan tool to spot any sudden jumps or dropouts.
7. Test continuity from sensor connector to ECM: If wiring damage is suspected, verify proper continuity and absence of shorts to ground or voltage.
8. If all else fails: Consult OEM service information for further ECM diagnostics or possible reprogramming.

Possible Repairs for P246A #

Once the root cause is found, the following repairs may resolve the P246A code:

• Replace the faulty exhaust gas temperature sensor if it’s out of spec or shows erratic/no signal.
• Repair or replace damaged wiring or connectors associated with the EGT sensor circuit.
• Fix any exhaust leaks near the sensor location to ensure accurate readings.
• Clean and secure electrical connectors to restore proper contact.
• Update or replace the ECM/PCM only if verified as faulty after all other checks.

Is It Safe to Drive with Code P246A? #

Limit your driving until repairs are made. While P246A does not always cause immediate breakdowns, it affects the emission control system and can lead to DPF regeneration failures or exhaust overheating, especially on diesel engines. Extended driving with this code risks expensive damage to aftertreatment components and may trigger limp mode. Address the issue as soon as possible.

Vehicles Most Commonly Affected by P246A #

The P246A code is more frequent on modern diesel vehicles equipped with aftertreatment systems, but can also appear in some gasoline models. Manufacturers and models where this code is often reported include:

• Ford F-Series (Diesel, 2011+)
• Chevrolet Silverado/GMC Sierra Duramax (Diesel, 2011+)
• Volkswagen Passat, Golf, Jetta TDI (Diesel, various years)
• RAM 2500/3500 Cummins (Diesel, 2013+)
• Toyota Hilux and Land Cruiser (Diesel, certain markets)
• Mercedes Sprinter (Diesel)

Common Mistakes & Best Practices with P246A #

Misdiagnosis is common with P246A because the symptoms may overlap with other emission codes. Following best practices helps ensure a proper fix:

• Do not replace the EGT sensor without testing it first. Faulty wiring or connectors are just as common.
• Always inspect for exhaust leaks near the sensor before condemning the sensor itself.
• Do not ignore the code—delayed repairs can lead to DPF failure or turbo damage.
• Clear the code and re-test after repairs to confirm the problem is resolved.
• Consult OEM service data for exact sensor location and specifications; some vehicles have multiple EGT sensors.

Quick FAQ for P246A #

Here are fast answers to some common questions about the P246A code:

• Q: Can I just clear the code and keep driving?
  A: Clearing the code without fixing the root problem will likely result in the code returning and may cause further damage or emissions failures.
• Q: Is this code covered under vehicle warranty?
  A: If your vehicle is still within the emissions warranty, the EGT sensor and related repairs may be covered. Check with your OEM dealer for details.