P242A: Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 3
The P242A code indicates a problem with the exhaust gas temperature (EGT) sensor circuit for Bank 1, Sensor 3. This sensor monitors exhaust temperature to protect the diesel particulate filter (DPF) and other emissions components. The PCM detects a voltage or resistance out of range, often due to a faulty sensor, wiring issues, or exhaust leaks. This can lead to incorrect regeneration cycles and potential DPF damage.
1. Most Common Causes
- Faulty exhaust gas temperature sensor
- Open or shorted wiring in sensor circuit
- Poor electrical connection at sensor or PCM
- Exhaust leak near sensor
- Corroded or damaged sensor connector
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Decreased engine performance
- DPF regeneration issues
- Possible limp mode activation
3. Step-by-Step Diagnosis
Step 1: Scan for codes and freeze frame data to confirm P242A.
Step 2: Visually inspect the EGT sensor and wiring for damage, corrosion, or loose connections.
Step 3: Test sensor resistance and voltage using a multimeter; compare to manufacturer specs.
Step 4: Check for exhaust leaks near the sensor that could affect readings.
Step 5: If sensor and wiring are okay, test the PCM output to the sensor circuit.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances. The faulty sensor can cause improper DPF regeneration, leading to clogged filter and expensive repairs. Short trips may be okay, but have it diagnosed soon.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. The sensor itself costs $50-$150, and labor adds $100-$250 depending on accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.