Exhaust Gas Temperature Sensor 4 Bank 1 Out of Range
The P247B code indicates that the exhaust gas temperature (EGT) sensor 4 on bank 1 is reporting a temperature outside the expected range. This sensor monitors exhaust temperature to protect the catalytic converter and diesel particulate filter (DPF) from overheating. Out-of-range readings can be caused by a faulty sensor, wiring issues, or actual exhaust temperature extremes due to engine misfires or excessive load.
1. Most Common Causes
- Faulty Bank 1 Sensor 4 exhaust gas temperature sensor with degraded thermal characteristics
- Corroded, heat-damaged, or loose wiring/connectors in the sensor circuit, including short to ground or voltage
- Open circuit in the harness between the sensor and PCM due to vibration fatigue or excessive heat
- Internal PCM failure in the EGTS signal conditioning circuit (less common)
2. Symptoms You Will Notice
- Check Engine Light on
- Reduced engine power or limp mode
- Poor fuel economy
- Possible DPF regeneration failure
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect EGT sensor 4 wiring and connector for damage.
Step 3: Compare EGT sensor 4 reading with other sensors using a scan tool.
Step 4: Test sensor resistance and voltage per manufacturer specs.
Step 5: Check for exhaust leaks near the sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as high exhaust temperatures can damage the catalytic converter or DPF. Limp mode may activate, reducing power.
How much does it cost to fix?▼
Replacing the EGT sensor typically costs $150-$300 including parts and labor. Diagnosis may add $50-$100.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.