Exhaust Valve Control Solenoid Circuit Low Bank 1
What it means
P0079 means the PCM detected a low-voltage (short-to-ground or open) condition in the exhaust valve control solenoid circuit on bank 1. This solenoid adjusts the variable valve system; a circuit fault leaves it stuck, causing rough running, reduced power, and higher emissions. The fault is electrical — solenoid, connector, or wiring — though low oil can also affect these oil-actuated solenoids.
Can I keep driving? Usually yes, with reduced performance — a valve-control circuit fault causes rough running and lost power but won't normally strand you.
Real-world scan data
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Rough or unstable idle
- Reduced power and poorer fuel economy
- Higher emissions
Common causes
Most likely first
- Short-to-ground or open (low-voltage fault) in the exhaust valve control solenoid circuit, bank 1Likely
- Failed exhaust valve control solenoidCommon
- Damaged or corroded wiring / loose connectorCommon
- Low or dirty engine oil affecting the oil-actuated solenoidLess often
- PCM control-circuit driver faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm the operating conditions.
- Inspect the bank 1 solenoid connector and wiring for shorts-to-ground or opens.
- Check engine oil level and condition, since these solenoids are oil-actuated.
- Measure the solenoid resistance against spec and command it with a scan tool.
- Replace the solenoid if faulty; suspect the PCM only after wiring is verified good.
FAQ
Quick answers
Is it safe to drive with P0079?+
Can I just clear P0079?+
Related codes
Read & clear P0079 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.