Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 4
The P2470 code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the exhaust gas temperature (EGT) sensor located in Bank 1, Sensor 4 (typically downstream of the diesel particulate filter or selective catalytic reduction system). This sensor monitors exhaust temperature to protect components and optimize emissions. A low circuit condition means the signal voltage is below the expected range, often due to a short to ground, faulty sensor, or wiring issues. This can lead to incorrect temperature readings, potentially causing reduced engine performance, increased emissions, or damage to exhaust aftertreatment components.
01. Most Common Causes
- Faulty exhaust gas temperature sensor
- Short to ground in sensor wiring or connector
- Corroded or damaged sensor connector
- Open circuit in sensor signal wire
- ECM internal fault (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor fuel economy
- Increased exhaust emissions
- Possible regeneration issues in diesel engines
03. Step-by-Step Diagnosis
Step 1: Connect a scan tool and verify the code P2470. Check for additional related codes.
Step 2: Visually inspect the EGT sensor Bank 1 Sensor 4 wiring and connector for damage, corrosion, or loose connections.
Step 3: Disconnect the sensor and measure resistance across sensor terminals; compare to manufacturer specifications (typically 100-200 kΩ at room temperature).
Step 4: Check for short to ground by measuring resistance between sensor signal wire and chassis ground; should be infinite.
Step 5: If wiring and sensor check out, test the ECM by monitoring sensor voltage with key on engine off; should be around 5V reference. If not, suspect ECM issue.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can lead to reduced engine performance, limp mode, or potential damage to exhaust aftertreatment components. Have the vehicle inspected as soon as possible.
How much does it cost to fix?▼
The cost to fix P2470 typically ranges from $150 to $400, including parts and labor. The sensor itself costs $50-$150, and labor is about $100-$250 depending on accessibility.