P2035 — Exhaust Gas Temperature Sensor Circuit Low #

Note: The code label may vary depending on the manufacturer. Always refer to your vehicle’s OEM documentation for exact terminology.

• “Exhaust Gas Temperature Sensor Circuit Low (Bank 1, Sensor 2)” — Ford
• “EGT Sensor 2 Circuit Low Voltage” — GM/Chevrolet
• “Exhaust Temperature Sensor 2 Low Input” — Volkswagen/Audi

Summary of DTC P2035 #

The P2035 diagnostic trouble code (DTC) indicates that the engine control module (ECM) has detected a low voltage condition in the circuit for an exhaust gas temperature (EGT) sensor. This sensor measures the temperature of the exhaust gases, helping the ECM manage emissions and protect key components such as the diesel particulate filter (DPF) and turbocharger. When the voltage signal from the EGT sensor falls below the expected threshold, the ECM triggers P2035. This code is most common on diesel vehicles but can appear on some gasoline engines equipped with advanced emissions controls. Prompt diagnosis and repair are important to prevent further damage and maintain optimal emissions performance.

Common Symptoms for DTC P2035 #

When P2035 is set, the vehicle may display a variety of symptoms—some subtle, others more pronounced. Recognizing these early signs can help prevent more serious issues down the road:

• Illuminated Check Engine Light (CEL): The most immediate and obvious sign.
• Reduced engine performance: In some cases, the ECU may limit power to prevent damage.
• Increased fuel consumption: Poor EGT readings can affect fuel mapping, leading to higher usage.
• DPF regeneration issues: Incorrect temperatures can interrupt or disable automatic particulate filter cleaning cycles on diesels.
• Rough idling or acceleration: Less common, but possible if the issue affects emissions control strategies.

Probable Causes for DTC P2035 #

The most frequent causes for a P2035 code revolve around electrical faults and sensor failures. Understanding the root cause is essential for a targeted repair:

1. Faulty exhaust gas temperature sensor (EGT sensor): Internal failure or sensor element damage.
2. Open or shorted wiring in the EGT sensor circuit: Damaged wires, broken connectors, or corrosion in the harness.
3. Poor electrical connection at the sensor or ECM: Loose, dirty, or corroded terminals.
4. Faulty ECM (rare): In rare cases, a malfunctioning engine control module may misinterpret the sensor signal.

Step-By-Step Diagnostic Procedure for P2035 #

Diagnosing P2035 effectively requires a systematic approach. Rushing can lead to misdiagnosis, so patience and attention to detail are key:

• Step 1: Use a scan tool to confirm the presence of P2035 and check for related codes (especially other EGT or DPF codes).
• Step 2: Locate the affected EGT sensor as specified in the OEM service information (typically Bank 1, Sensor 2 means downstream from the turbo or after the DPF on Bank 1).
• Step 3: Visually inspect the EGT sensor and harness for obvious damage, corrosion, or heat-related deterioration.
• Step 4: Disconnect the sensor and check the electrical connector for loose, bent, or corroded pins.
• Step 5: Using a multimeter, measure the resistance of the EGT sensor. Compare readings to OEM specifications (usually a few ohms at room temperature, but always check your manual).
• Step 6: Check wiring continuity between the sensor and ECM. Repair any open or shorted circuits as needed.
• Step 7: If all wiring and the sensor check out, consider testing or re-flashing the ECM as a last resort.

Possible Repairs for P2035 #

Repair strategies for P2035 will always depend on the underlying cause identified during diagnosis. Here are the most common solutions:

• Replace the faulty EGT sensor: The most frequent fix when the sensor shows incorrect resistance or obvious damage.
• Repair or replace damaged wiring/connectors: Address any visible wear, burn marks, or corrosion in the harness.
• Clean or tighten sensor and ECM connections: Remove corrosion and ensure solid electrical contact.
• Replace the ECM: Only after confirming all other components are working and per OEM recommendation.

Is It Safe to Drive with Code P2035? #

Driving with P2035 is generally possible for short distances, but it is not recommended for extended use. The vehicle may enter a reduced power mode or experience higher emissions, and, on diesel models, improper DPF regeneration could eventually cause expensive filter or turbo damage. If the check engine light is flashing or you notice major performance issues, reduce driving and seek a professional diagnosis promptly.

Vehicles Most Commonly Affected by P2035 #

While P2035 can appear on any modern vehicle using EGT sensors, it is most frequently reported on late-model diesels and some turbocharged gasoline engines, especially those with advanced emissions systems:

• Ford Super Duty Diesel (Power Stroke engines)
• GM Duramax Diesel (Chevrolet Silverado, GMC Sierra)
• Ram Cummins Diesel (2500/3500 series)
• Volkswagen/Audi TDI models
• Mercedes-Benz BlueTEC diesels
• Some BMW and Volvo diesel models

Common Mistakes & Best Practices with P2035 #

Misdiagnosis is all too common with sensor-related codes. Avoiding these pitfalls saves time, money, and frustration:

• Replacing the EGT sensor without checking wiring: Faulty harnesses are a frequent cause.
• Ignoring OEM procedures: Always follow manufacturer-specific diagnostic steps and resistance specs.
• Clearing the code before fixing the cause: The code will return if the root issue isn’t addressed.
• Using non-OEM sensors: Aftermarket parts may not communicate properly with the ECM.

Quick FAQ for P2035 #

Still have questions? Here are two of the most common concerns, answered by a master tech:

• Q: “Can I just clean my EGT sensor to fix P2035?”
  A: No, cleaning rarely restores proper function. Most EGT sensor failures are internal or due to wiring—not contamination.
• Q: “Will P2035 cause my vehicle to fail emissions testing?”
  A: Yes, in most regions, any active check engine light or emissions-related DTC will result in an automatic failure.