B13B1

Code

Generic B — Body

Driver Seat Position Sensor Circuit Malfunction

Brand: Generic

Type: B — Body

Views: UK: 7 EN: 15 RU: 4

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Page language: EN

Causes

Damaged or disconnected seat position sensor
Corroded, frayed, or pinched wiring/harness under the seat
Poor connector contact (corrosion, bent terminals, improper seating)
Faulty seat control/occupant detection module
Water intrusion or foreign material in sensor assembly
Intermittent fault due to movement (broken wire inside harness)

Symptoms

Seat memory not recording or recalling positions
Seat position reading wrong or erratic on diagnostic tool
Related features disabled (airbag occupant classification, belt pretensioner logic, seatbelt reminder)
DTCs present intermittently, especially after seat movement
Possible warning light(s) for SRS/airbag or body systems

What to check

Read and record freeze frame and live data with a capable scan tool
Visually inspect seat underside: connectors, wiring, and harness routing (look for chafing at rail and seat hinge points)
Check connector pins for corrosion, bent pins, or pushed-out terminals
Perform wiggle test while monitoring live data or DTCs to reproduce intermittent faults
Verify vehicle battery voltage is within 11–14.5 V during tests
Check for water stains or foreign material around sensor and module areas

Signal parameters

Reference supply (Vbat) on sensor supply pin: ~11–14.5 V with ignition ON
Signal output (position) expected: typically 0.5–4.5 V or 0–5.0 V depending on sensor type — should change smoothly with seat travel
Sensor ground continuity: near 0 Ω (expect
Resistance across potentiometer-style sensor: varies smoothly with travel (no open circuits)
CAN/serial communication: seat module should report position percentage (0–100%) on live data when available

Diagnostic algorithm

Connect a capable scan tool and confirm B13B1 and any related codes; record freeze frame and live data.
With ignition ON perform a live-data check of seat position sensor reading while moving seat through full travel; observe for smooth, proportional change in signal voltage or position percentage.
Visually inspect connectors and harness from sensor to seat module; repair any damaged insulation, pins, or connectors. Ensure connectors are fully seated.
Perform a wiggle test of wiring while observing live data and DTC status to identify intermittent opens/shorts.
Measure supply voltage and ground at the sensor connector. If supply or ground out of range, trace back to fuse/relay and module grounds.
Measure signal voltage at sensor while moving seat; if signal is erratic or out of range, disconnect sensor and check for open/short to supply or ground.
If sensor wiring and connectors are good but signal is incorrect, test sensor resistance or output per manufacturer procedure; replace sensor if out of specification.
If sensor and harness good, check seat control/occupant detection module communication; reflash or replace module if confirmed faulty. Perform calibration/teach procedure for seat position after replacement.
Clear codes and perform functional test and road test if required; verify no recurrence and that related systems (airbag/seat memory) operate normally.

Likely causes

Broken or chafed wire from seat position sensor to seat module (common at seat rail flex point)
Loose or corroded connector at sensor or module
Failed position sensor (potentiometer, Hall effect, or travel sensor)
Seat module has failed or lost calibration after service

Fault status

⚠️ Status

Driver Seat Position Sensor Circuit Malfunction: sensor output is open, shorted, intermittent, or out of expected range. Inspect sensor, wiring, connectors, and seat module; calibration or module replacement may be required. May affect seat memory and occupant-sensing functions.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 2.5 hours