What it means
During cold start, the intake manifold runner control on bank 2 cannot reach the closed position. Tumble/swirl effect for cold-start mixture preparation is reduced.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The intake manifold runner control moves internal flaps to change airflow and create swirl for cold-start combustion. The engine control module monitors the Bank 2 runner position during a cold start and sets P2AB4 when the flaps do not reach the commanded closed position, reducing the intended swirl.
Common causes
Most likely first.
- Runner actuator or linkage fault
- Carbon or debris restricting runner movement
- Wiring or connector fault
Symptoms
- Check-engine light may be on
- Rough idle after a cold start
- Hesitation or reduced power while cold
How to diagnose it
- Use a scan tool to check freeze-frame data and compare the Bank 2 runner command with its reported position during the cold-start fault.
- With the engine off, inspect the Bank 2 runner actuator, linkage, and connector for damage, looseness, or disconnected parts.
- Check the Bank 2 runner wiring for chafing, corrosion, or loose terminals that could interrupt actuator control or position feedback.
- If accessible, observe whether the Bank 2 linkage moves through its range when commanded with a scan tool, and note where it stops or binds.
- If the linkage is obstructed, inspect the Bank 2 runners for carbon or debris; test the actuator and its circuit against the manufacturer's specification.
Common fixes
- Reconnect or repair a loose or damaged Bank 2 runner-control connector or wiring.
- Free and clean carbon or debris that prevents the Bank 2 runners from closing.
- Repair or replace a damaged Bank 2 runner linkage.
- Replace a failed Bank 2 runner actuator after confirming its circuit and linkage are sound.
Can I keep driving?
If the engine runs smoothly once warm and power is normal, a short, gentle trip may be possible, but avoid hard acceleration while cold. Rough running or persistent power loss can worsen drivability and emissions, so arrange diagnosis soon.
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.