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 condition in the exhaust gas temperature (EGT) sensor circuit for Bank 1, Sensor 4. This sensor is typically located downstream of the diesel particulate filter (DPF) or selective catalytic reduction (SCR) system. A low voltage reading can be caused by a faulty sensor, wiring issues, or a short circuit. This condition can affect emissions control and may lead to reduced engine performance or limp mode.
1. Most Common Causes
- Faulty EGT sensor (Bank 1, Sensor 4) with high internal resistance or open circuit
- Damaged, corroded, loose, or shorted-to-ground wiring or connectors in the signal or reference circuit
- Exhaust leak upstream of the sensor causing the sensing element to run cooler than actual gas temperature
- Internal PCM failure (rare)
- Improper sensor installation (loose threads, missing gasket)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor fuel economy
- Increased emissions
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the EGT sensor and wiring for damage, corrosion, or loose connections.
Step 3: Measure the sensor resistance and compare to manufacturer specifications; a short circuit indicates a faulty sensor.
Step 4: Check the voltage signal at the ECM connector; if low, repair wiring or replace sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it may cause reduced performance and potential damage to the exhaust system. Limp mode may activate, limiting speed.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and sensor location.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.