What it means
Same as P059A with the signal voltage above the plausible range. 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
The position sensor for active grille shutter A reports the shutter's position to the control module. P059C sets when the sensor A signal is higher than its expected range, often because the signal wire is shorted to supply voltage; the module may not know whether the shutter is open or closed.
Common causes
Most likely first.
- Signal shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light
- Active grille shutter warning, if equipped
- Shutters may remain open or closed
How to diagnose it
- Use a scan tool to confirm P059C and check grille-shutter A live position data against the commanded position to verify that the signal is high or implausible.
- Inspect sensor A's wiring and connector at the grille for a pinched wire touching B+, chafing, water entry, corrosion, or pushed-back pins.
- Using the wiring diagram, test the sensor A signal for a short to supply voltage and check its connector terminal contact.
- Wiggle the harness while monitoring the sensor reading to locate an intermittent high signal.
- If wiring is sound, test sensor A and the shutter control module against the manufacturer's specification.
Common fixes
- Repair or reroute a pinched sensor A signal wire that touches a supply wire.
- Repair chafed wiring and secure it away from supply conductors.
- Clean or replace corroded or damaged sensor connector terminals.
- Replace the position sensor or control module only after the signal circuit tests correctly.
Can I keep driving?
You can generally drive if engine temperature remains normal, but monitor it closely because the shutters may not respond correctly. If they remain closed and the engine begins to overheat, stop driving.
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.