P05B1

Code

Generic P — Powertrain

Active Grille Air Shutter B Control Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 40 RU: 35

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Page language: EN

Causes

Open or high-resistance wiring in the AGAS B control circuit
Poor or corroded connector or pin at the shutter actuator or module
Blown fuse or failed relay supplying the grille actuator circuit
Faulty AGAS B actuator/motor or position sensor
Poor ground connection
Faulty body control module (BCM) / powertrain control module (PCM) or software issue

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
Active grille shutter B stuck open or stuck closed
Reduced aerodynamic control affecting fuel economy or engine warm-up
Possible diagnostic trouble codes related to grille actuator or HVAC performance

What to check

Scan for stored codes and freeze-frame data; record data and clear codes to retest
Visually inspect wiring harness and connectors at the grille shutter B actuator for damage, corrosion, or water intrusion
Check relevant fuse(s) and relay(s) for continuity and correct rating
Backprobe the actuator connector with key ON (engine OFF) to measure supply and control signals
Command the grille shutter B with a scan tool while monitoring the connector and actuator response
Measure motor coil resistance at the actuator connector (compare to specification)

Signal parameters

Battery/supply voltage at actuator feed: ~11–14 V with key ON
Control signal: typically PWM or switched ground from BCM; expected 0–12 V pulses with variable duty when commanded
Position/feedback sensor (if present): nominal ~0.5–4.5 V depending on position
Motor winding resistance (typical): a few ohms to a few tens of ohms; open circuit if >1 kΩ or infinite
Open-circuit condition: measured continuity >10 kΩ or no voltage change when commanded

Diagnostic algorithm

Retrieve freeze-frame and live data with a scan tool; note any other related codes.
Visually inspect the grille shutter B actuator, connector and harness for obvious damage, corrosion or water ingress.
Check fuses and relays that feed the grille shutter circuit; replace any blown fuses and retest.
With connector disconnected, measure supply voltage at the actuator power pin with key ON (should be ~12 V) and check ground continuity to chassis.
Backprobe the control pin while commanding the shutter B open/close with a scan tool; verify a switching/PWM signal or change in voltage. If no command signal is present, suspect wiring or module output.
Measure the resistance of the actuator motor/coil at the connector. If open or out of spec, replace the actuator.
Perform a continuity check from the actuator connector to the controlling module connector to confirm no open or high-resistance circuit (repair any broken wires or corroded pins).
If wiring and actuator check good but no proper module output, inspect module grounds and power supplies; consider module replacement only after wiring and actuator confirmed good.
After repairs, clear codes and verify proper operation by commanding the shutter through multiple cycles and re-checking for stored codes.

Likely causes

Disconnected or corroded connector at the grille shutter B actuator
Broken conductor or damaged insulation in harness to actuator B
Failed actuator motor or internal open winding
Blown inline fuse supplying actuator circuit
Faulty module output (rare) after wiring and actuator verified good

Fault status

⚠️ Status

Stored when the control module detects an open or excessively high-resistance condition in the Active Grille Air Shutter B control circuit while commanding the shutter. The fault may set the MIL and freeze-frame data.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours