B1652

Code

Other B — Body

Seat Driver Recline Backward Circuit Open

Brand: Other

Type: B — Body

Views: UK: 21 EN: 39 RU: 31

AI status

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Page language: EN

Causes

Open or damaged wiring in the recline-backward circuit (broken conductor, chafing, pinched harness under seat)
Corroded, loose, or disconnected connector at the seat motor, switch, or control module
Blown fuse or faulty relay supplying the seat motor/control
Failed recline switch on the seat (backward position contact open)
Failed recline motor or motor internal open winding
Faulty seat control module / body control module (driver) or poor module chassis ground

Symptoms

Driver seat will not recline backward when commanded
No audible motor noise or only intermittent/weak motor operation
DTC B1652 stored in the vehicle memory; possible related seat system warning
Seat works in other directions (forward/up/down) but not backward
Intermittent operation that may change when seat wiring is moved

What to check

Verify key/ignition and power mode required for seat adjustment are correct before testing
Visual inspection of wiring and connectors under the seat for damage, corrosion, or loose terminals
Check relevant fuses/relays for continuity and correct rating
Scan vehicle for stored seat-related DTCs and freeze frame data
Wiggle-test harness and connectors while operating recline backward to reproduce fault
Measure voltage at the seat motor connector while commanding recline backward

Signal parameters

Expected supply voltage at motor or switch: approximately battery voltage (~11–13.5 V) when commanded (varies by vehicle)
Expected ground or return path continuity to chassis ground: near 0 Ω
Motor winding resistance (typical): low ohms (often single- to double-digit ohms); open circuit = OL/infinite
Control module command signal (on some systems): switched +12 V or low-side transistor drive — use DVOM or scope to observe switching
Stall/operating current: typically several amps; expected current draw when motor is powered (use ammeter or clamp meter to compare with spec)

Diagnostic algorithm

Retrieve and record related codes and freeze frame data with a diagnostic scanner. Clear codes and attempt to re-create to verify repeatability.
Turn ignition off and perform a thorough visual inspection of the seat harness, focusing on areas that move or pass under the seat and seat track pinch points. Repair damaged insulation or terminals as needed.
Check fuses and relays for the seat/comfort system. Replace any blown fuses with correct rating and re-test.
With ignition on and seat command applied to recline backward, measure voltage at the motor connector harness pin(s). If no voltage present, trace back toward the switch and control module.
If voltage is present at the harness but motor does not run, disconnect motor and measure its winding resistance. An open winding indicates a bad motor requiring replacement.
If motor shows open winding, confirm by bench testing motor with a fused 12 V supply (observe polarity if directional) — only perform bench tests with appropriate fusing and safety precautions.
If motor is good but no drive voltage from the module, check continuity between module output and motor connector and inspect/control module grounds. Repair any open circuits or poor grounds.
Test the recline switch for correct operation (continuity in backward position). Replace switch if contacts do not close.
If wiring, switch, and motor check good, consult wiring diagram and test the seat control module output with a scope or DMM per service manual; replace module if confirmed faulty.
After repairs, clear codes, cycle power and verify full function of recline backward and that B1652 does not return.

Likely causes

Damaged/loose connector or wiring in harness under the seat
Failed recline motor winding or internal open circuit
Faulty seat switch (backward contact) or poor switch contacts
Blown fuse or interrupted power/ground feeding the recline circuit

Fault status

⚠️ Status

B1652 — Seat driver recline backward circuit open. Open circuit detected in the recline-backward control; seat may not move backward. Inspect wiring, connectors, fuses, switch, motor, and module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours