What does code P0011 mean on a Hummer and is it safe to drive?
P0011: Camshaft Position A – Timing Over-Advanced or System Performance (Bank 1). Here's what it means on your Hummer, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
The intake camshaft on bank 1 is more advanced than the PCM commanded, or the VVT system isn't responding as expected. Often caused by low/dirty oil or a faulty oil control valve.
Common causes for your Hummer
- Low or dirty engine oil (most common—change oil first)
- Failed or sludged oil control valve (OCV/VVT solenoid)
- Stretched or worn timing chain
- Stuck VVT actuator (cam phaser)
Symptoms
- Check Engine Light
- Rough idle or rattling on cold startup
- Poor fuel economy
- Reduced power
Typical fixes
- Oil change with correct viscosity oil (often resolves it)
- Clean or replace oil control valve
- Replace timing chain if stretched
- Replace cam phaser if faulty
Repair cost range
For a Hummer, repairs for P0011 often fall between $50 and $1200, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.