What it means
Same as P05A4 on shutter B. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
Active grille shutter B uses a control circuit to receive movement commands from the vehicle's control module. This code sets when the module detects the control-line signal above its expected range, such as when the line is shorted to a supply source.
Common causes
Most likely first.
- Control line shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light
- Shutter B may not respond to commands
- Cooling fan may run more often
How to diagnose it
- Record freeze-frame data and check whether shutter B responds to a scan-tool command while the fault is present.
- Inspect B's control harness for pinching, chafing, water entry, or connector corrosion that could connect the control line to a supply.
- Check connector terminals for corrosion, poor contact, or a terminal pushed out of position.
- With the manufacturer's wiring information, test the control line for an unintended connection to power.
- If the harness tests correctly, check the actuator and controlling module for a fault that holds the control signal high.
Common fixes
- Clean or repair corroded connector terminals and restore a secure connection.
- Repair a pinched or chafed control wire shorted to supply.
- Replace a faulty shutter B actuator if it is confirmed to drive the line high.
- Repair or replace a control module only after its output fault is confirmed.
Can I keep driving?
You can usually drive cautiously if engine temperature remains normal, but monitor the temperature gauge because shutter B may not follow cooling commands. Stop if the engine overheats, and avoid heavy loads or long periods of idling until the fault is repaired.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.