P201B — Intake-manifold runner actuator supply voltage, bank 1 — supply voltage too low

P201B concerns intake-manifold runner actuator supply voltage, bank 1. The monitor reports supply voltage below its accepted range for the named circuit or device. The low value is assigned to this actuator supply. It does not by itself establish a vehicle-wide low-battery-voltage problem.

Affected system: Intake-manifold airflow control

Symptoms

• Warning light may illuminate
• Related system function may be impaired
• Vehicle-specific symptoms vary

Possible causes

• Low or unstable supply voltage, fuse or relay fault, poor ground, or wiring damage
• Related wiring, connector, power or ground fault
• Vehicle-specific mechanical or control issue

What to check

• Record stored and pending codes and freeze-frame data
• Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
• Confirm measured values against the vehicle service information
• Retest under the conditions that set the code
• Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
• Repair the verified cause and confirm the code does not return

Also written as: P201B-00, P201B00 (some scan tools add the fault-type byte, e.g. -00).