Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 3
The P242D code indicates that the Engine Control Module (ECM) has detected a high voltage signal from the exhaust gas temperature (EGT) sensor located after the diesel particulate filter (DPF) on Bank 1, Sensor 3. This sensor monitors exhaust temperature to protect the DPF and other components. A high circuit condition typically means the sensor signal voltage is above the expected range, often due to a short to power, internal sensor failure, or wiring issues. This can lead to incorrect temperature readings, affecting DPF regeneration and potentially causing emissions system problems.
01. Most Common Causes
- Faulty exhaust gas temperature sensor
- Short to voltage in sensor wiring or connector
- Corrosion or damage in the sensor connector
- ECM software or hardware issue (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Possible DPF regeneration issues or forced regeneration
- Engine may enter limp mode or reduced power
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm code P242D and check for additional codes.
Step 2: Visually inspect the EGT sensor (Bank 1, Sensor 3) and its connector for damage, corrosion, or loose pins.
Step 3: Measure sensor voltage at the connector with the engine off; compare to manufacturer specifications (typically 0.5-4.5V).
Step 4: Check for short to power by disconnecting the sensor and testing for voltage on the signal wire.
Step 5: If wiring is intact, replace the EGT sensor and clear the code.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause DPF damage or improper regeneration, leading to costly repairs. Short trips may be possible but should be minimized.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a DIY replacement of the sensor, or $150 to $300 if professionally diagnosed and replaced, including labor.