P0024 is a generic OBD2 trouble code. It indicates that your Hummer H2’s camshaft position “B” is over advanced or a system performance issue. There are many potential causes for this code, and a lot of them are easy to check.
- VVT– Variable Valve Timing
- Bank 2– The side of the engine with the second cylinder
- Camshaft Position “B“- Is either the exhaust, rear, or right camshaft
P0024 Definition: Camshaft Postion “B” – Over Advanced Or System Performance – Bank 2
Modern engines, such as the one in your Hummer H2, use variable valve timing to increase engine efficiency (more power and fuel mileage) by allowing for a broader powerband.
Camshaft Position “B”
The ECM uses camshaft actuators to control the position of the camshaft based on driver input to deliver more power when requested and more efficiency when cruising.
Camshaft position “B” is either the exhaust, rear, or right camshaft.
Over Advanced
The engine timing is too advanced in relation to where it should be.
Bank 2
Bank 2 is the side of your H2’s engine with the second cylinder. P0024 only occurs on vehicles with two banks, so you’ll have to deal with this.
Cylinder heads are not perpendicular to one another. They can’t be, as the crankshaft can’t turn two rods occupying the same space, which means that one cylinder head will always be closer to the engine accessories than the other.
As a rule (most of the time), Bank 1 is the cylinder head that’s further forward.
Toyta H2: P0024 Symptoms
Here are the most common issues the H2 will have with P0024. How bad the engine runs will depend on how far over-advanced the timing is.
- Difficulty Starting– Like any vehicle with ignition timing that is too far advanced, it can be really difficult to start your H2 with P0024, particularly when the engine is at normal operating temperature.
- Idle Issues– The engine may idle erratically, or feel like it’s “lumpy”.
- Stalling– With the camshaft timing too far advanced, the engine will feel more “normal” under heavier throttle loads.
- Mileage– When the camshaft can’t adjust itself to optimize combustion, mileage will certainly suffer.
- Service Engine Soon– This is rarely the only symptom of P0024.
P0024 Causes: Hummer H2
Here are some of the most normal causes of P0024, starting with the easier-to-check stuff first.
Here’s a great video on diagnosing P0014. It’s the Bank 1 side of this code, which means everything is the same, just cylinder head one.
While this is a more challenging trouble code to diagnose, it is possible to do at home. Here are the most common causes of P0024:
- Oil Issues– Camshaft Actuators don’t function properly with old/no oil. They operate hydraulically and need to use the oil to move up and down. An oil change and a little drive time is often enough to clear P0024.
- Wiring Issues– If the wiring to the camshaft actuator has gone bad it can cause P0024. An old, brittle, or cut wiring harness can mess up the signal coming from the camshaft actuator. After checking the oil, this is good place to start diagnosing P0024 in the Hummer H2. Is the harness connector plugged in? Is there visible damage to any of the wiring? If so, it may be time to replace the harness. How to diagnose a short in a vehicle (article: Backyard Mechanic).
- Bad Camshaft Actuator– The camshaft actuator is a solenoid that engages the camshaft and actually controls its timing. They typically aren’t that expensive. If it’s not a wiring issue, it’s a very good chance that this’ll be the problem.
- Timing Chain– If the timing chain has jumped a tooth (or two), it can leave the engine running advanced, and throw the P0024. Certainly, this is not the most likely cause, but it is certainly possible. Timing chain jumped (this site).
Conclusion
Good luck diagnosing P0024 in your Hummer H2. If there is anything that you can add to improve the article below, or if you have any questions, please leave them down in the comments.