Intake Manifold Runner Position Sensor Low Voltage Bank 2
The P2021 code indicates that the intake manifold runner position sensor on bank 2 is reporting a voltage lower than the expected range. This sensor monitors the position of the intake manifold runner control (IMRC) flaps, which adjust air intake length for optimal performance. A low voltage signal suggests a short to ground, open circuit, or a faulty sensor. This can lead to reduced engine power, poor fuel economy, and increased emissions.
1. Most Common Causes
- Faulty intake manifold runner position sensor
- Short to ground in the sensor wiring
- Corroded, oxidized, or damaged sensor connector pins
- Excessive resistance in the signal circuit due to loose terminals or splices
- Internal ECM/PCM failure affecting the reference voltage supply
- Mechanically stuck or damaged intake runner actuator
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or hesitation
- Poor fuel economy
- Rough idle or stalling
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2021 and check for other codes.
Step 2: Visually inspect the sensor and wiring for damage, corrosion, or loose connections.
Step 3: Test sensor voltage and ground with a multimeter; compare to manufacturer specs.
Step 4: If wiring is intact, replace the intake manifold runner position sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause reduced performance and potential engine damage. Have it diagnosed promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on the vehicle and shop rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.