P0022 is a relatively common general OBD2 trouble code. If your H1 has Variable Valve Timing (We’ll be referring to it as VVT a lot), it can get this code.
What is VVT?
VVT changes the frequency and distribution of gases entering and exiting the combustion chamber. It allows the engine to act like it has different camshaft profiles at different RPMs.
This ability to alter valve timing is excellent for both power and fuel economy.
P0022 Definition: Intake “A” Camshaft Position – Over-Retarded- Bank 2
The Hummer H1 utilizes camshaft actuators to change the valve lift depending on the RPM of the motor. VVT allows for a more efficient cam profile at any speed.
With P0022, the camshaft actuator is leaving the timing retarded (fuel is ignited later than at the optimal time).
Camshaft Position Actuators change the lift of the camshaft up to 25 degrees. They are hydraulic, which means that they use the vehicle’s engine oil to control lift. Low or dirty oil is known to cause P0022.
Bank 2
Bank 2 is the side of the engine with the second cylinder. It’s almost always the cylinder head that’s set further back in relation to the engine accessories.
Hummer H1 P0022 Symptoms
When the timing is over retarded, it can cause some motor issues. Here are some of the typical symptoms of P0022 in the Hummer H1:
- Poor Idle Quality– If the camshaft actuator fails it can be tough for the engine to find the right idle speed or idle smoothly.
- Decreased Gas Mileage– Now the engine can no longer adjust its cam timing on the fly, it will no longer be able to produce optimal combustion, which equals poor economy.
- Lost Power– The H1’s engine will not be able to produce as much power. This is because the cam profile will not allow it run a performance power curve when you need more power.
- Service Engine Soon Light– Most of the time, you’ll be able to feel or see one of the above symptoms, but if you can’t, the service engine soon light will still come on and let you know that something is wrong.
- Hard to Start Motor– With the timing over retarded, it is going to be difficult to start the motor, especially when it is warm.
Hummer H1 P0022 Causes
There are quite a few different things that can cause the P0022. Here are the most common causes. We’ll start with the easiest ones to check.
Engine Oil
If the engine oil is dirty or low, it may cause the actuator to malfunction. If water gets into the oil, the viscosity won’t be enough to provide the proper oil pressure to the camshaft actuators.
If this is the case, your H1 will probably have P0012 as well.
Engine Timing
If the camshaft(s) are no longer synced to the crank properly (such as if the timing chain jumped a tooth), it can cause the engine timing to be off enough to throw the P0022 even though it’s not the Actuator’s fault. Here’s more on that from this site: Timing Chain Jumped Symptoms and Diagnosis
Bad Intake Camshaft Position Actuator Solenoid
The actuator solenoid itself can go bad over time. You certainly don’t want to start here since a lot of the time it’ll be something else that causes the P0022 to appear.
This video gives a thorough walkthrough on how to diagnose a bad camshaft actuator.
Wiring Issues
The wiring from the solenoid to the ECM can become damaged or broken. When this happens, it will throw the P0022 OBDII code. The wiring harness to the intake camshaft position sensor may also develop a poor connection— Youtube: How to Find an Open or Short the Fast Easy Way.
Bad ECM (highly unlikely)
If your Hummer H1’s computer goes bad, it may throw this code along with other issues. Here’s how to tell if you have a bad ECM Autoblog: Symptoms of a Bad ECM.
Conclusion
If it has been an excessive period of time since the last time you’ve had an oil change, or you find that there may be a reason to believe that the oil thickness is wrong, change the oil and see if that helps anything.
Good luck diagnosing the P0022 in your Hummer H1. If you would like to add anything, please leave a comment below.