P059B

What it means

P059B is the generic code for the Active Grille Air Shutter 'A' position sensor circuit range/performance. The control unit compares the shutter position feedback with the position it commanded, or with expected limits, and the two do not agree plausibly. The shutter may be stuck, slow, only partly moving, or the position signal may be unreliable.

Symptoms

• Malfunction indicator lamp on, sometimes with a related grille shutter or active aero warning
• Engine running hotter than normal in traffic or on a hot day
• Air conditioning performing poorly at low speed or when idling
• Slightly worse fuel economy or more wind noise at speed
• Rattling, buzzing or clicking from the front of the car as the actuator tries to move the shutter
• No noticeable symptoms other than the stored code

Possible causes

• Shutter vanes jammed or restricted by road debris, ice, snow, dirt or a damaged slatlikely
• Broken, stiff or detached linkage or vane on the active grille shutter assemblylikely
• Faulty shutter actuator or its internal position sensor giving an implausible signallikely
• Damaged wiring, corroded or loose connector terminals, or water ingress in the actuator circuitpossible
• Front-end impact damage or a misaligned bumper or grille distorting the shutter assemblypossible
• Low or unstable supply voltage or a poor earth affecting the actuatorpossible
• Control unit fault or outdated software, where the manufacturer lists this as a known cause for the modelrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting temperature, speed and whether other cooling or actuator codes are present
2. Visually inspect the grille shutter from the front and from under the bonnet for debris, ice, broken vanes, bent linkage or impact damage
3. Move the vanes by hand, if the design allows with the ignition off, to check for binding, stiffness or a loose linkage
4. Inspect the actuator wiring and connector for chafing, corrosion, bent pins, moisture and poor terminal tension
5. Use a scan tool with bidirectional control to command the shutter open and closed, and compare the commanded position with the live position feedback
6. Check the actuator supply, earth and position sensor signal against the manufacturer wiring diagram, as pin layout and signal type vary by model
7. Check the battery and charging voltage, and look for technical service bulletins or software updates for the vehicle
8. After repair, clear the code and road test to confirm the shutter moves through its full range without the code returning

How to fix

• Clear debris, ice or dirt and free the vanes, then check the full range of movement
• Repair or replace the damaged shutter assembly, vanes or linkage
• Replace the shutter actuator or position sensor if it is faulty, and carry out any relearn or adaptation the manufacturer requires
• Repair damaged wiring, clean or replace corroded connector terminals and seal out moisture
• Repair or realign front-end damage that is distorting the shutter assembly
• Update the control unit software only where the manufacturer identifies an outdated calibration as the cause

Can I keep driving?

Nearby codes

• P059AGenericActive Grille Air Shutter A Position Sensor Circuit
• P059CGenericActive Grille Air Shutter A Position Sensor Circuit High