B3A29

Code

Generic B — Body

Active Aerodynamic Feature Control Module B Power Mode Circuit Low Voltage

Brand: Generic

Type: B — Body

Views: UK: 24 EN: 39 RU: 23

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Page language: EN

Malfunction or inoperable active aerodynamic components controlled by Module B (flaps, spoilers, vents)
Warning message or lamp related to aerodynamic system
Intermittent operation of aerodynamic features
Other modules reporting communication or related errors if supply is shared
Possible reduced vehicle performance or mode restrictions if system disabled

Scan for additional DTCs and record freeze-frame/volatile data
Verify battery voltage at rest and with engine/crank (expected ~12.4–12.8 V resting, ~13.5–14.8 V running)
Inspect and test fuse(s) and relay(s) powering Active Aerodynamic Feature Control Module B for continuity and proper operation
Visually inspect connectors and wiring at Module B for corrosion, bent pins, damaged insulation, or water intrusion
Backprobe module power pin with ignition ON and with system operating, measure voltage and note stability
Check module ground(s) for secure connection and low resistance to chassis (

Battery resting voltage: ~12.4–12.8 V (nominal range)
Charging voltage (engine running): ~13.5–14.8 V
Module supply/power-mode circuit voltage with key ON: ~11.5–14.8 V depending on vehicle (compare to battery)
Voltage drop between battery positive and module power pin: ideally
Ground resistance from module ground to chassis:
Supply ripple/noise: should be minimal; excessive fluctuation indicates poor connection or load issue

Retrieve freeze-frame data and related DTCs; note conditions when fault occurred (ignition state, engine load, temperature).
Verify battery condition and terminals. Charge or replace battery if voltage is low or battery fails load test.
Inspect and test all fuses and relays in the power path to Module B. Replace any blown fuses and confirm relay operation.
With key ON, backprobe the module power pin and measure voltage. Compare to battery voltage. Check for heavy voltage drop or intermittent loss.
Inspect the module connector and harness for corrosion, bent pins, water entry, or damage. Repair or clean connector as needed.
Check module ground(s) for secure mounting and low resistance to chassis/battery negative. Repair any high-resistance grounds.
Perform a continuity and insulation resistance check from the module power pin to the battery/fuse/relay. Repair wiring faults found.
Wiggle harnesses while observing voltage and scan tool for intermittent faults. Use backprobe/oscilloscope if needed to characterize noise or dropouts.
If wiring, connectors, fuses and battery are good and supply still low, consider module internal fault. Verify software/firmware status and reflash if applicable per manufacturer guidance.
After repairs, clear codes and perform road test or repeat conditions to confirm the fault does not return.