What it means
The control circuit of camshaft profile actuator B (intake side) on bank 2 reports a control circuit low 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
Actuator B controls the alternate, higher-lift profile of the intake cam on bank 2. The control module monitors its circuit and sets P2B37 when the signal is too low, which can happen if the wire is grounded, the coil is internally shorted, or a corroded connection adds resistance.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in actuator coil
- Connector pins corroded - high contact resistance
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 review live data for the bank 2 intake profile command and related actuator faults.
- Inspect actuator B's bank 2 intake connector and harness for corrosion, rubbed-through insulation, or contact with ground.
- Check the connector terminals for corrosion or looseness that could create high contact resistance.
- With the circuit isolated as the manufacturer specifies, test the control wire for a short to ground.
- Measure actuator B's coil against the manufacturer's specification, then follow the circuit test procedure to confirm the source of the low signal.
Common fixes
- Clean and secure corroded or loose terminals at the bank 2 intake actuator B connector.
- Repair control-wire insulation or wiring that is shorted to ground.
- Replace actuator B if its coil is internally shorted.
- Repair a module connection if testing locates the fault there.
Can I keep driving?
Avoid hard acceleration and long trips if power is reduced, since the bank 2 intake cam may not reach its alternate profile and the engine may run roughly or stall. If stalling occurs, stop driving until the fault is repaired.
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.