P201B
Intake Manifold Runner Control Actuator Supply Voltage Low (Bank 1)
The supply voltage feeding the IMRC actuator on bank 1 is below the lower limit — typically a fuse, relay, or harness fault on the supply rail.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Supply fuse blownCommon
- Open supply wirePossible
- Supply relay contacts pittedPossible
Parts involved
- IMRC Actuator
- IMRC Supply Relay
- IMRC Supply Fuse
P201B is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.