P0024 OBD-II Code: Camshaft Timing Over-Advanced (Bank 2)

The P0024 OBD-II code signals a camshaft timing issue on Bank 2, often affecting performance in vehicles like BMW 3 Series or Toyota Camry. This guide explains P0024, its causes, symptoms, and fixes, with detailed case studies to help you resolve the issue.

1. What is P0024?

P0024 is an OBD-II diagnostic trouble code (DTC) defined as "Camshaft Position 'B' - Timing Over-Advanced or System Performance (Bank 2)." It indicates that the Engine Control Module (ECM) has detected that the exhaust camshaft timing on Bank 2 (the side of the engine without cylinder 1) is too advanced, or the variable valve timing (VVT) system isn’t performing correctly. This issue is common in vehicles with VVT systems, which adjust camshaft timing for optimal performance.

Role of the VVT System

The VVT system adjusts the timing of the camshaft to improve engine efficiency, power, and emissions. The ECM uses inputs from camshaft and crankshaft position sensors to control the VVT solenoid, which regulates oil flow to the camshaft actuator. A P0024 code means the timing is too far advanced (e.g., beyond 10 degrees of the target position), often due to oil pressure issues or sensor faults.

Common Trigger Conditions

• Camshaft timing exceeds the ECM’s target by a significant margin.
• VVT system performance is inconsistent or erratic.
• Mechanical or electrical issues affect the VVT system or sensors.
  

2. Causes of P0024 OBD-II Code

P0024 can result from various issues in the VVT system, such as a P0024 VVT solenoid failure or a P0024 timing chain issue. Here are common causes with examples:

• Faulty VVT Solenoid
  The solenoid fails to regulate oil flow properly. A 2008 BMW 3 Series (E90) had P0024 due to a clogged VVT solenoid from carbon buildup.
  Cause: Oil contamination or wear.
• Low or Dirty Engine Oil
  Insufficient oil pressure or dirty oil affects VVT operation. A 2012 Audi A4 (B8) triggered P0024 due to using incorrect 10W-40 oil instead of the required 5W-30.
  Cause: Improper maintenance or oil specs.
• Faulty Camshaft/Crankshaft Position Sensor
  A defective sensor sends incorrect timing data. A 2013 Ford Mustang had P0024 from a failing camshaft position sensor on Bank 2.
  Cause: Sensor wear or electrical issues.
• Timing Chain/Belt Issues
  A stretched or jumped timing chain disrupts camshaft timing. A 2011 Toyota Camry triggered P0024 due to a stretched timing chain after 150,000 miles.
  Cause: High mileage or lack of maintenance.
• ECM Issues
  ECM software glitches or hardware faults misinterpret timing data. A 2010 BMW 3 Series had P0024 resolved after an ECM software update.
  Cause: Outdated software or hardware failure.

For more on VVT system mechanics, refer to the SAE standards on variable valve timing.

3. Symptoms of P0024 in Vehicles

P0024 affects engine performance and efficiency. Common symptoms include:

• Check Engine Light On
  The MIL illuminates due to a detected issue.
• Poor Engine Performance
  Reduced power during acceleration due to incorrect timing, often felt as sluggish response on highways.
• Rough Idle or Stalling
  Engine may shake or stall at idle, especially noticeable at stoplights, due to timing misalignment.
• Decreased Fuel Efficiency
  Incorrect timing leads to higher fuel consumption, lowering miles per gallon.
• Abnormal Engine Noise
  Rattling sounds from a stretched timing chain or loose components, often heard during startup.
• Acceleration Shudder
  Engine may shudder or hesitate when accelerating, particularly under load (e.g., uphill driving).

4. Vehicles Prone to P0024 Code

P0024 is common in vehicles with VVT systems, particularly those with high mileage or improper maintenance. Here’s a breakdown with specific case analyses:

• BMW 3 Series (E90, 2006-2011)
  Issue: Clogged VVT solenoid due to carbon buildup from infrequent oil changes (every 15,000 miles instead of 7,500). Symptom: Rough idle and MIL on. Fix: Replaced solenoid and used 5W-30 synthetic oil.
• Toyota Camry (2010-2015)
  Issue: Timing chain stretched after 150,000 miles, causing over-advanced timing. Symptom: Engine noise and poor acceleration. Fix: Replaced timing chain and tensioner.
• Ford Mustang (2011-2017)
  Issue: Faulty camshaft position sensor on Bank 2, sending incorrect signals. Symptom: Stalling at idle. Fix: Replaced sensor and updated ECM software.
• Audi A4 (B8, 2008-2015)
  Issue: Low oil pressure from using incorrect 10W-40 oil (spec: 5W-30). Symptom: Reduced fuel efficiency. Fix: Oil change with correct spec and cleaned VVT system.
• Hyundai Sonata (2011-2016)
  Issue: VVT solenoid failure due to sludge buildup. Symptom: Shudder during acceleration. Fix: Replaced solenoid and performed oil flush.

5. Related Codes to P0024

P0024 often appears with other codes that can help pinpoint the issue. Here are some related codes to check for:

• P0011 - Camshaft Position 'A' Timing Over-Advanced (Bank 1)
  Similar to P0024 but affects Bank 1 (the side with cylinder 1). Indicates over-advanced timing on the intake camshaft.
• P0021 - Camshaft Position 'A' Timing Over-Advanced (Bank 2)
  Also affects Bank 2 but relates to the intake camshaft. Often shares causes like VVT solenoid issues.
• P0340 - Camshaft Position Sensor Circuit Malfunction
  Points to a general camshaft position sensor issue, which may cause incorrect timing data leading to P0024.
• P0345 - Camshaft Position Sensor 'A' Circuit Malfunction (Bank 2)
  Specifically relates to the camshaft position sensor on Bank 2, a common culprit for P0024.

Checking these codes can help narrow down the root cause, such as a shared sensor or VVT system issue.

6. How to Diagnose P0024 OBD-II Code

Diagnosing P0024 requires a systematic approach. Follow these steps:

Step 1: Scan for Codes

Use an OBD-II scanner to confirm P0024 and check for related codes (e.g., P0011 for Bank 1 timing issues or P0345 for sensor issues on Bank 2).

Step 2: Check Engine Oil

Inspect oil level and condition. It should be clean and meet manufacturer specs (e.g., 5W-30 for BMW). Example: The Audi A4 had P0024 due to incorrect oil viscosity.

Step 3: Monitor Live Data

Check live data with a scanner:
- Camshaft position: Should align with ECM target (within 5-10 degrees).
- VVT solenoid operation: Should respond to ECM commands.

Step 4: Inspect the VVT Solenoid

Test the solenoid with a multimeter (resistance typically 7-12 ohms, per manual). Example: The BMW 3 Series solenoid was clogged, causing P0024.

Step 5: Check Sensors

Test camshaft and crankshaft position sensors for proper voltage (0.5-4.5V) and resistance. Example: The Ford Mustang’s camshaft sensor failed.

Step 6: Inspect Timing Components

Check the timing chain/belt for stretch or misalignment. Example: The Toyota Camry’s chain was stretched, causing over-advanced timing.

Step 7: Verify ECM

Update ECM software if needed. Example: The BMW 3 Series issue resolved after an ECM update.

7. How to Fix P0024 on BMW 3 Series and Other Vehicles

Apply these solutions based on your diagnosis:

• Replace the VVT Solenoid
  Install a new solenoid (cost: $100-$300). Fixed the 2008 BMW 3 Series.
• Change Engine Oil
  Use the correct oil spec and replace if dirty (cost: $50-$150). Resolved the 2012 Audi A4 issue.
• Replace Camshaft Position Sensor
  Install a new sensor (cost: $50-$200). Fixed the 2013 Ford Mustang.
• Replace Timing Chain/Belt
  Install a new chain and tensioner (cost: $500-$1500). Corrected P0024 in the 2011 Toyota Camry.
• Update ECM Software
  Apply a firmware update (cost: $0-$150). Fixed the 2010 BMW 3 Series.

Watch a Repair Video

8. Repair Costs and Precautions

Costs

• VVT Solenoid: $100-$300.
• Engine Oil Change: $50-$150.
• Camshaft Position Sensor: $50-$200.
• Timing Chain/Belt Replacement: $500-$1500.
• ECM Update: $0-$150.

Precautions

• Use the correct oil viscosity (e.g., 5W-30 for BMW).
• Torque VVT solenoid bolts to spec to avoid leaks.
• Clear codes after repairs to reset the ECM.

9. Preventive Measures for P0024

• Change engine oil every 5,000-7,500 miles with the correct spec.
• Inspect VVT system components during major services (every 60,000 miles).
• Replace timing chain/belt per manufacturer schedule (e.g., 100,000 miles for Toyota).
• Keep ECM software updated with manufacturer releases.

11. P0024 Diagnostic Summary

The P0024 OBD-II code indicates a camshaft timing issue on Bank 2, often caused by a faulty VVT solenoid, low oil pressure, or timing chain problems. This guide provides steps to diagnose and fix P0024 in vehicles like BMW 3 Series and Toyota Camry, ensuring optimal engine performance.