What it means
The control circuit of camshaft profile actuator B on the exhaust side of bank 1 reports a control performance/stuck off condition. Cam profile B (high-lift or VTEC-style) cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Profile actuator B controls the alternate cam profile on the exhaust side of bank 1. The control module checks whether this exhaust profile changes when commanded; this code indicates the bank 1 exhaust system remains stuck in its off or low-lift state.
Common causes
Most likely first.
- Actuator stuck in low-lift position
- Oil pressure to actuator insufficient
- Carbon or debris buildup preventing free movement
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
How to diagnose it
- Record freeze-frame data and compare commanded and reported profile states for the bank 1 exhaust profile actuator.
- Check engine oil level and condition because oil pressure may be needed to move the bank 1 exhaust profile mechanism.
- Inspect the bank 1 exhaust actuator connector, harness, and accessible oil feed for damage, loose terminals, leakage, or blockage.
- Test actuator command and circuit operation using the vehicle's service information, noting whether the actuator responds.
- If the control circuit and oil supply are sound, inspect the bank 1 exhaust profile mechanism for deposits, debris, or binding.
Common fixes
- Correct low or degraded oil and any restriction in the actuator's oil supply.
- Repair poor connections or damaged wiring at the bank 1 exhaust profile actuator.
- Clean deposits from the actuator mechanism where permitted by service information.
- Replace a bank 1 exhaust profile actuator that fails to move when commanded.
Can I keep driving?
Reduced mid-range power and increased fuel use may continue while the bank 1 exhaust profile stays in its low-lift state. Avoid hard acceleration and stop if rough running progresses to stalling.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.