B3A34

Code

Generic B — Body

Active Aerodynamic Feature A Actuator Position Sensor Not Learned

Brand: Generic

Type: B — Body

Views: UK: 20 EN: 34 RU: 23

AI status

Completed

ready

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Page language: EN

New or replaced actuator/position sensor not calibrated (learning procedure not performed)
Battery disconnected or low voltage during learning event, causing loss of learned data
Failed or intermittent position sensor (potentiometer/Hall effect)
Damaged wiring or poor connector connection to actuator/sensor
Actuator mechanical binding or obstruction preventing full travel
Control module software fault or corrupted learned data

Malfunction/information lamp or message indicating actuator/feature fault
Aerodynamic device (grille shutter, spoiler, air dam) stuck open, closed or in a default position
Reduced fuel economy or engine cooling anomalies if shutters fail to operate
Actuator attempts to move but stops or does not reach expected position
No response from the aerodynamic feature when commanded

Verify current battery voltage and charging system health (stable 12–14.5 V) before tests
Scan for stored DTCs and freeze frame; note any related codes (power, communication, actuator)
Visually inspect actuator, harness, and connectors for damage, corrosion or poor seating
Attempt to operate the actuator via a scan tool’s bi-directional control and observe motion
Check fuses and power/ground at the actuator connector with key on
Confirm whether a learn/calibration procedure is recorded as completed in the module (scan tool parameters)

Position sensor raw value or percentage (e.g., 0–255 or 0–100%) — should change smoothly during travel
Position sensor voltage (typical potentiometer/Hall): ~0.5 V at one end to ~4.5 V at the other end across travel
Power supply to actuator: battery voltage (~12 V) present with ignition on
Ground continuity: low ohm path from actuator ground to chassis
Module status/flags: 'learn complete' bit should be set after calibration
CAN/serial messages: position and status bytes present and updating during actuation

Retrieve and record all related DTCs and freeze-frame data. Note any battery or communication codes.
Check battery voltage and connections. Recharge or connect stable power if battery is low.
Visually inspect actuator and harness. Repair any damaged wires or connectors before further testing.
With a scan tool, attempt a basic actuator command (open/close). Observe for movement and listen for unusual noises.
While commanding the actuator, monitor the position sensor output (raw value and voltage). Confirm it moves smoothly and reaches expected end values.
If sensor output is erratic or absent, backprobe the connector: verify reference voltage, signal voltage and ground. Repair wiring or replace actuator/sensor as needed.
If actuator moves but the module still reports 'not learned', perform the manufacturer prescribed learning/calibration procedure using a capable scan tool following service instructions.
After successful learn, clear codes and verify proper operation across multiple cycles and ignition cycles. Re-scan to ensure code does not return.
If learning fails repeatedly, check for software updates or module faults. Consider replacement of the actuator or control module per service info.
Document repairs and recheck vehicle driveability and any related systems (cooling, aero performance).

Recent repair or replacement of the aerodynamic actuator or its sensor without performing the prescribed learn/calibration
Corroded or loose connector at the actuator harness
Sensor output voltage out of expected range when actuator is moved
Actuator cannot reach end stops due to mechanical interference
Vehicle battery discharged or disconnected, clearing learned values