P0025: Camshaft Position Timing Over-Retarded (Bank 2)
The P0025 code indicates that the Engine Control Module (ECM) has detected that the camshaft timing on Bank 2 is retarded (delayed) beyond the specified range. This typically occurs when the variable valve timing (VVT) system fails to advance the camshaft as commanded, often due to issues with the oil control solenoid, low oil pressure, or a stretched timing chain. Bank 2 refers to the side of the engine opposite cylinder #1.
1. Most Common Causes
- Low engine oil level or degraded oil
- Bank 2 VVT control solenoid stuck or damaged
- Clogged VVT solenoid screen filter
- Mechanically defective VVT actuator (camshaft gear)
- Electrical issues in VVT solenoid or CMP sensor wiring (short, open circuit)
- Faulty camshaft position (CMP) sensor
- Incorrect timing chain/belt tension (slipped a tooth)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or engine misfire
- Reduced engine power and acceleration
- Poor fuel economy
- Engine may stall or hesitate
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data. Check for other related codes like P0010-P0014.
Step 2: Inspect engine oil level and condition; change oil and filter if dirty or low.
Step 3: Test the VVT solenoid on Bank 2 for proper operation using a multimeter or scan tool.
Step 4: Check for oil pressure at the VVT solenoid and camshaft phaser; repair any blockages.
Step 5: Inspect timing chain/belt tension and alignment; replace if stretched or slipped.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the retarded timing can cause engine performance issues, increased emissions, and potential damage to the catalytic converter or engine internals.
How much does it cost to fix?▼
The cost varies depending on the cause. A simple oil change or VVT solenoid replacement can cost $50-$150, while timing chain replacement can be $500-$1500 or more.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.