P0079 Code: Meaning, Symptoms, Causes & Fix

Overview

Symptoms

• reduced performance
• increased fuel use
• check engine light

Common causes

• Disconnected or loose connector affecting exhaust valve control circuit low (bank 2)
• Open circuit in wiring
• Connector pin damage/corrosion or harness stress near related components

How to diagnose P0079

1. Confirm P0079 and capture freeze-frame data with a professional scan tool.
2. Inspect wiring, connectors, and grounds related to exhaust valve control circuit low (bank 2) for obvious defects.
3. Use a continuity test from module pin to component to identify opens/high resistance.
4. Check for related DTCs to identify the root-cause chain before replacing parts.
5. After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code P0079

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with P0079?

Most vehicles can be driven short-term with P0079, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

1. Repair obvious wiring/connector faults first to prevent repeat parts replacement.
2. Address the root fault mode (open) in the exhaust valve control circuit low (bank 2) circuit/system.
3. Apply the required relearn/adaptation procedure if specified by service information.
4. Road-test and verify P0079 remains cleared under the conditions that originally set the code.

Fix options

• Restore continuity and verify pin tension.
• Repair open circuit and secure connector lock.
• Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$200-$900

Common mistakes when diagnosing P0079

• Replacing parts without verifying voltage, ground, and signal integrity first.
• Ignoring related stored/pending codes that indicate upstream faults.
• Skipping post-repair verification drive cycle and readiness checks.

P0079 in common vehicles

P0079 appears across makes such as BMW, Mercedes-Benz, Audi, Volvo. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes P0079?

P0079 is commonly set by open faults affecting exhaust valve control circuit low (bank 2).

How much does it cost to fix P0079?

For P0079, repair costs are typically $200-$900 depending on exact root cause, labor rates, and part quality.

Can I clear P0079 without repair?

You can clear P0079 temporarily, but the code usually returns until the underlying fault is corrected.

Helpful tools

• Estimate repair cost
• Decode your VIN
• Calculate fuel cost