P2079: Intake Manifold Tuning Valve Position Sensor Circuit Intermittent Bank 1
The P2079 code indicates an intermittent signal from the intake manifold tuning (IMT) valve position sensor on bank 1. This sensor monitors the position of the IMT valve, which adjusts intake runner length to optimize engine performance across RPM ranges. An intermittent fault suggests a loose connection, damaged wiring, or a failing sensor, causing the PCM to detect an erratic or missing signal. This can lead to reduced fuel economy, power loss, and potential drivability issues.
1. Most Common Causes
- Faulty IMT valve position sensor with intermittent internal contact
- Damaged sensor circuit wiring: short to ground/power or intermittent open circuit
- Loose, corroded, or damaged connectors with broken terminals or retainers
- IMT valve/actuator mechanically stuck or with excessive play causing unstable readings
- Internal PCM failure (rare)
2. Symptoms You Will Notice
- Check Engine Light on
- Reduced engine power or hesitation
- Poor fuel economy
- Rough idle or stalling
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect IMT valve sensor connector and wiring for damage or corrosion.
Step 3: Test sensor signal voltage with a multimeter while wiggling harness to reproduce intermittent fault.
Step 4: Check IMT valve for carbon buildup and clean if necessary.
Step 5: Replace sensor if tests indicate failure.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short trips, but reduced performance and fuel economy may occur. Prolonged driving could lead to further issues, so repair is recommended.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts and labor, depending on the cause (sensor replacement vs. wiring repair).
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.