What it means
During cold start, the intake manifold runner control on bank 1 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
Intake manifold runners on bank 1 change airflow to improve mixture preparation during a cold start, and their actuator moves them toward the closed position for that condition. This code sets when the bank 1 runner control stays open instead of reaching the commanded closed position, reducing the intended tumble or swirl and potentially causing a rough cold idle or hesitation.
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
- Capture freeze-frame data and compare bank 1 runner command and position, if available, with coolant temperature and engine speed to confirm the fault occurs during a cold start.
- With the engine off and cool, inspect the bank 1 runner actuator, linkage, connector, and wiring for disconnection, damage, or binding.
- Check the bank 1 runner linkage for carbon or debris that prevents it from moving fully to the closed position.
- Use a scan tool's actuator test, if supported, to command the bank 1 runners and observe whether the actuator and linkage move through their range.
- If movement is obstructed or absent, test the actuator circuit and actuator against the manufacturer's specification before repairing the linkage or replacing a failed part.
Common fixes
- Reconnect or repair a loose bank 1 runner actuator connector or damaged wire.
- Free the bank 1 runner linkage if debris or carbon is restricting its movement.
- Repair or replace a damaged actuator linkage.
- Replace the bank 1 runner actuator if it fails testing.
Can I keep driving?
A short drive may be reasonable if the engine runs safely, but expect rough idle or hesitation after a cold start and arrange repair soon. Avoid hard acceleration while the engine is cold, and stop if the engine stalls or loses enough power to make driving unsafe.
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.