OBD Codes List

Diagnostic reference · P059C

P059C

Active Grille Air Shutter A Position Sensor Circuit High

System
Speed and idle control (P code)
Lamp
Check Engine Light
Category
Powertrain - Computer and Auxiliary Controls

What it means

P059C stands for Active Grille Air Shutter A Position Sensor Circuit High. P059C is a P code, so the fault sits in the engine, transmission and emissions systems. For P059C, the second digit places it in speed and idle control. For P059C, work through the cause list below, cheapest checks first.

Where it lives

For P059C, the sensor sits on the circuit this code reports. The description of P059C reports a fault at the sensor.

What to check first

For P059C, pull the connector and inspect the terminals for spread, corrosion or backed-out pins before testing anything else.

Check these first

  • P059C: Faulty sensor or actuator in the control circuit
  • P059C: Wiring, connector, or fuse problem for the affected output
  • P059C: Low or unstable system voltage from the battery or charging system
  • P059C: Failed PCM/ECM or a software error
  • P059C: Poor ground connection for the control module

What to do next

P059C is a fault in the speed and idle control system. The steps below are general, so what actually failed on your vehicle may not be what P059C names.

  1. P059C: Verify battery voltage and charging system health first
  2. P059C: Read all related module codes with an OBD-II scanner
  3. P059C: Inspect wiring, connectors, and grounds for the affected circuit
  4. P059C: Test the sensor or actuator with live data and actuation commands
  5. P059C: Check for PCM software updates or TSBs before replacing modules

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Updated

Generic SAE J2012 definition. Last updated 2026-08-30.