Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P05B5 Active Grille Air Shutter B Supply Voltage Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Shutter B is the second active grille shutter – at GM, Ford and Stellantis the lower one in the bumper. Shutters cut drag and speed warm-up when closed and open for cooling; CARB names them as an off-cycle CO2 technology and treats the actuator as an output component. Smart actuators report over LIN (loss of communication: U0285); a fault usually costs fuel and warm-up time, a closed shutter can make the engine run hot under load. P05B5 means the battery supply of actuator B via fuse or relay is missing or open; without it there is no movement, and smart actuators drop off the LIN bus. No manufacturer document available to us uses this code, like its shutter A counterpart. VW's check measures supply and ground at the actuator connector; GM feeds its actuators via a relay but uses other codes.

Likely causes

Fuse blown or relay faulty
Broken wire or connector off in the lower front end
Ground connection open
Actuator faulty internally

Symptoms

  • Check engine light on
  • Lower shutter inoperative
  • Possibly also U0285

Repair estimate

DifficultyEasyDIY possible
Parts and labour€10–300
Time0.3–1.5 h

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

Parts involved

grille shutter actuator bactuator power supplyfuse relay

Related codes

P05B6P05B7P05B1U0285P05A6

References: law.cornell.edu, static.nhtsa.gov, gsi.ext.gm.com.