P0024: “B” Camshaft Position – Timing Over-Advanced or System Performance (Bank 2)

Quick answer

• What the code means: The P0024 code indicates that the exhaust camshaft on Bank 2 is more advanced than the Engine Control Module (ECM) has commanded it to be.
• Severity: It's generally safe to drive home, but you should have it inspected as soon as possible. Ignoring it can lead to reduced engine performance, poor fuel economy, and potential engine damage over time.
• Most common cause: The most frequent culprit is a low or dirty engine oil level.

What the P0024 code means

The official OBD-II definition for P0024 is "'B' Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)".

Let's break that down in plain English. Your car's engine has a system called Variable Valve Timing (VVT). This system precisely adjusts the timing of the engine's intake and exhaust valves to improve performance, fuel economy, and emissions. It does this by changing the position of the camshafts relative to the crankshaft.

The "B" camshaft refers to the exhaust camshaft, and "Bank 2" refers to the side of the engine that does not contain cylinder #1 (typically the side closer to the front of the vehicle on V6 and V8 engines). The P0024 code is set when the Engine Control Module (ECM) detects that the exhaust camshaft for Bank 2 is advanced beyond the position it has commanded. In other words, the camshaft has rotated further forward in its timing range than the computer wants it to, and it's not returning to the expected position.

This is a problem because incorrect camshaft timing can disrupt the engine's combustion cycle, leading to a variety of noticeable symptoms.

Common symptoms

When the P0024 code is triggered, you will almost certainly see the Check Engine Light on your dashboard. You may also experience one or more of the following symptoms:

• Rough idling: The engine may shake or run unevenly when the car is stopped.
• Engine stalling: The engine might die unexpectedly at low speeds or when coming to a stop.
• Reduced engine power: The car may feel sluggish and have trouble accelerating.
• Decreased fuel economy: You may notice you're visiting the gas station more often.
• Hard starting: The engine might take longer than usual to start.
• Rattling noise from the engine: This can indicate a problem with the VVT actuator (phaser).

Common causes

Here are the most common causes of a P0024 code, ranked from most likely to least likely:

1. Low or dirty engine oil: This is by far the most common cause. The VVT system uses pressurized engine oil to adjust the camshaft position. If the oil is low, dirty, or the wrong viscosity, it can't flow properly, leading to timing issues.
2. Faulty camshaft oil control valve (OCV): Also known as a VVT solenoid, this valve directs the flow of oil to the camshaft phaser. It can get stuck open or clogged with sludge, causing the camshaft to become over-advanced.
3. Faulty camshaft phaser: The phaser is the mechanical gear on the end of the camshaft that actually rotates it. It can become clogged with debris or fail mechanically, getting stuck in an advanced position.
4. Wiring or connector issues: Damaged wires or a poor connection to the camshaft position sensor or the oil control valve can disrupt signals to and from the ECM.
5. Timing chain or belt issues: A stretched timing chain, a worn-out tensioner, or jumped timing can cause the base timing to be off, triggering this code.
6. Faulty camshaft position sensor: While less common, the sensor that reads the camshaft's position can fail, sending incorrect data to the ECM. This usually triggers other codes as well.
7. ECM failure: This is very rare, but the Engine Control Module itself can fail. This should only be considered after all other possibilities have been exhausted.

How a technician diagnoses it

A qualified technician will follow a systematic process to pinpoint the cause of the P0024 code.

1. Verify the code: The first step is to connect an OBD-II scanner to the vehicle's diagnostic port and confirm that P0024 is present. They will also check for any other related codes and review the freeze-frame data, which is a snapshot of the engine's operating conditions at the moment the code was set.
2. Check engine oil: The technician will check the oil level and condition. If the oil is low, they will top it off. If it's dirty or the wrong type, they will recommend an oil and filter change. This simple step often resolves the issue.
3. Inspect wiring and connectors: They will visually inspect the wiring harnesses and connectors for the camshaft position sensor and oil control valve on Bank 2 for any signs of damage, corrosion, or loose connections.
4. Test the oil control valve (VVT solenoid): Using a bi-directional scan tool, the technician can command the Bank 2 exhaust VVT solenoid to activate. They will monitor the camshaft position sensor data to see if the actual camshaft angle changes as commanded. A good reading will show the camshaft angle changing in response to the command. If the angle doesn't change, or if it's stuck at a high value (over-advanced), it points to a problem with the solenoid or the phaser.
5. Test the camshaft position sensor: The technician will check the sensor's signal using a digital multimeter or oscilloscope to ensure it is sending a correct and consistent signal to the ECM.
6. Inspect the timing components: If the above steps do not identify the problem, the technician may need to perform a more in-depth inspection of the timing chain, guides, and tensioners for wear or damage. This is a more labor-intensive process.

Typical repair cost

The cost to repair a P0024 code can vary widely depending on the underlying cause. All prices are estimates and will vary by location and vehicle make/model.

• Oil and filter change: $50 – $150
• Camshaft oil control valve (VVT solenoid) replacement: $150 – $400 (The part itself is typically $50-$150, with the rest being labor).
• Camshaft position sensor replacement: $100 – $300
• Camshaft phaser replacement: $600 – $2,000+ (This is a labor-intensive job that often involves removing the timing cover).
• Timing chain replacement: $1,000 – $2,500+

Can I keep driving with this code?

While you can likely drive the vehicle home or to a repair shop, it is not recommended to continue driving with an active P0024 code for an extended period. The over-advanced timing can lead to poor engine performance, increased fuel consumption, and stalling. More importantly, if the issue is related to low oil pressure or failing timing components, continued driving could lead to severe and expensive engine damage.

Related codes

• P0014: "