P2009
Intake Manifold Runner Control Circuit Low (Bank 1)
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The P2009 code means the PCM has detected abnormally low voltage in the intake manifold runner control (IMRC) circuit for bank 1. While P2008 indicates an open (broken) circuit, P2009 specifically flags a low-voltage condition, which usually points to a short to ground somewhere in the IMRC wiring or a failing solenoid drawing too much current.
The IMRC system controls butterfly valves inside the intake manifold to optimize airflow at different engine speeds. When the electrical circuit has a low-voltage fault, the PCM cannot properly control these valves, which may result in slightly reduced engine performance, particularly at lower RPMs where the IMRC system provides the most benefit.
This is a relatively low-severity code and your vehicle should be safe to drive while you arrange repairs. Start your diagnosis by visually inspecting the wiring and connector at the IMRC solenoid for signs of damage, chafing, or corrosion. A multimeter can be used to check for shorts to ground in the wiring harness. In many cases, a simple wiring repair or connector replacement resolves the issue without the need for more expensive parts.
Severity
Symptoms
- •Check engine light on
- •Reduced engine power during acceleration
- •Minor fuel economy decrease
- •Possible engine surging or hesitation
- •Slightly rough idle
Likely Causes
A damaged wire that contacts the vehicle body or engine creates a short to ground, pulling the IMRC control circuit voltage below the expected range and triggering this low-circuit code.
Internal failure of the IMRC solenoid can cause its resistance to drop below specifications, resulting in excessive current draw and a low-voltage reading in the control circuit.
Water intrusion or corrosion at the IMRC solenoid connector can create unintended electrical paths to ground, causing the circuit voltage to read lower than the PCM expects.
If the IMRC uses an electric motor actuator, internal short-circuiting of the motor windings can cause low resistance and excessive current draw, triggering the low circuit code.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Inspect and repair damaged wiring in the IMRC circuit
- Replace the IMRC control solenoid
- Clean or replace corroded connectors
- Replace the IMRC actuator motor if applicable