Active Grille Shutter Problems — How To Diagnose and Fix

How to Fix Active Grille Shutter Problems

The active grille shutter has three jobs: 1) reduce aerodynamic vehicle drag, 2) increase MPG during periods when engine cabin cooling loads are low and high airflow through the condenser and radiator are not required, and 3) help keep coolant at a high enough temperature to provide adequate heat for the cabin. During all those periods, the shutters are closed. But these units aren’t perfect. Because they’re mechanical louvers run by a motor, they can develop active grille shutter problems that set a check engine light.

If the ECM determines that high airflow is required across the radiator fins, it will open one or both of the shutters. It determines active grille shutter position based on inputs from the vehicle speed, coolant temperature, fan state, refrigerant system pressures, AC compressor state, and outside ambient temperature.

Active grille shutters can have single or multiple sections

If the outside temperature is low, the ECM will keep the shutters in the closed position until needed.

Active grille shutter actuator

The grille shutter actuator is an electric motor with position sensor. The ECM uses the position sensor to compare commanded position with actual position.

Active grille shutter problems, codes P059F and/or P151E

P059F — Desired Active Grille Air Shutter Position ≠ Desired Active Grille Air Shutter Position Achieved — Exceeded Number of Attempts

P151E — LIN Bus Communication Malfunction

How to diagnose Active grille shutter actuator

Disconnect the electrical connector from the actuator.

The connector should have three wires. Use a wiring diagram to identify the power, ground and digital network wire.

Test for less than 10Ω between the ground terminal in the connector and the ground termination point on the body. If you detect more than 10Ω, disconnect the body ground termination and retest. You should see less than 2Ω between the connector terminal and the ground wire.

If the resistance is greater than 2Ω, repair the open in the ground wire.

If less than 2 Ω, clean the ground termination point and retest.

Check for power at the connector. If no power, check the circuit fuse