Powertrain, generic · Fuel and air metering, auxiliary emission controls

P0079 Exhaust Valve Control Solenoid Circuit Low Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

A solenoid valve on the cylinder head controls oil flow for the variable valve control on the exhaust side of bank 1. Depending on the manufacturer it drives a camshaft phaser (for example on Nissan engines) or a valve lift changeover (for example on Subaru engines). This code family reports electrical faults in its control circuit; P0079 means the voltage in the control circuit is too low, typically a short to ground; depending on the driver stage an open solenoid winding can also set this code. Other manufacturers report the same valve under the "camshaft position actuator" codes instead. Valve control is then switched off or stays in its base position.

Likely causes

Control wire shorted to ground, or solenoid winding open (driver-dependent)
Shorted turns in the solenoid coil
Corroded or oil-soaked connector
Output driver or supply in the engine control module faulty

Symptoms

  • Check engine light on
  • Less power, especially at high engine speed with lift changeover
  • Rough idle possible
  • Follow-up codes for camshaft timing or misfire possible

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–350
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

valve control solenoid exhaust bank1valve control solenoid wiringengine control module

Related codes

P0078P0080P0085P0027P0013

References: law.cornell.edu, automotivetechinfo.com, en.wikipedia.org.