B1B7D

Code

LAND ROVER B — Body

Air distribution actuator - rear

Brand: LAND ROVER

Type: B — Body

Views: UK: 14 EN: 32 RU: 12

AI status

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Page language: EN

Causes

Failed rear air distribution actuator (motor/gears)
Mechanical obstruction in vent/air flap
Damaged wiring harness or broken wires to actuator
Poor connector contact or corrosion at actuator connector
Faulty ground or supply voltage to actuator
HVAC control module fault or corrupted adaptation/calibration

Symptoms

Rear vent fails to change mode or stays in one position
No airflow or reduced airflow from rear vents
Clicking, grinding or repeated actuator noise from rear HVAC area
Rear temperature distribution incorrect or cannot be adjusted
Related HVAC warnings or multiple HVAC DTCs present
Actuator fails commanded movement when using climate controls or diagnostics

What to check

Retrieve all HVAC/cluster DTCs with a capable scan tool and record freeze frame data
Listen for actuator noise while changing vent mode; observe rear vents for movement
Visually inspect actuator, vent linkage and surrounding for obstructions or broken gears
Check relevant HVAC fuses and relays
Inspect actuator connector for corrosion, bent pins or water ingress
Perform basic voltage check at actuator connector (key on) for supply and ground

Signal parameters

Supply voltage at actuator: ~11–14 V (key on/engine running)
Ground: good continuity to chassis (near 0 Ω to ground)
Position feedback signal: typically 0–5 V or pack-specific position message (varies by model)
Actuator current draw: normally low; transient up to ~1–2 A during movement (excessive current indicates jam or seized motor)
Command signal: PWM or serial/lin/can message depending on model (verify with manufacturer data)

Diagnostic algorithm

Connect a factory-level or capable aftermarket scan tool. Read and record B1B7D and any additional HVAC codes; note freeze frame and related events.
Attempt to operate rear air distribution using the climate controls while observing vent movement and listening for noises.
Visually inspect the rear actuator, linkages, and vent area for foreign objects, broken gears or disconnected linkages; clear obstructions if present.
Inspect and if needed remove the actuator connector; check for corrosion, bent pins and secure fit.
Verify HVAC fuses/relays related to actuators; replace if blown and retest.
With connector attached, measure supply voltage and ground at the actuator connector (key on). Then command actuator while measuring — supply should remain ~12 V and ground stable.
Use scan tool to command the actuator and monitor position feedback (0–5 V or software position readout). If command is present but no movement, suspect mechanical/electrical failure of actuator.
If electrical supply and control signals are present but actuator does not move, remove actuator and bench-test with direct 12 V (observe movement and current). Inspect internal gears for stripping.
Repair or replace failed component: replace actuator if faulty, repair wiring/connector or clear obstruction as required. After repair, clear codes, perform HVAC actuator calibration/adaptation using the scan tool, and retest for proper operation.
If issue persists after actuator replacement and wiring verified, investigate HVAC control module and perform software updates or module replacement per manufacturer guidance.

Likely causes

Actuator motor or internal gear failure
Wiring/connector fault (corrosion, open, short)
Mechanical obstruction preventing flap movement
Poor ground or missing supply voltage
HVAC control module needing adaptation/software update

Fault status

⚠️ Status

Rear air distribution actuator fault — position/movement or feedback circuit error

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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Repair manuals

Manual library for LAND ROVER

413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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B1B7D — Air distribution actuator - rear