B13B6

Code

Generic B — Body

Seat Position Sensor Circuit Malfunction

Brand: Generic

Type: B — Body

Views: UK: 9 EN: 11 RU: 10

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty seat position sensor (potentiometer/encoder)
Open or shorted wiring between sensor and control module
Poor connector connection, corrosion or bent pins at seat harness
Water/moisture intrusion or damaged harness under seat
Faulty seat control / occupant classification module or software error
Mechanical damage to sensor from seat movement or crash

Symptoms

DTC stored and/or warning lamp on (seat/airbag/occupant classification warning)
Seat memory or automatic seat position functions inoperative or inconsistent
Seat position reported incorrectly or not at all on diagnostic data
Intermittent faults that occur only when moving the seat
Potential effects on airbag/occupant classification systems (follow SRS warnings)

What to check

Scan for B13B6 and any related codes; record freeze-frame or live data
Visual inspection of seat, rails and wiring harness for damage, chafing or water
Inspect connectors at seat sensor and module for corrosion, bent pins or partial engagement
With ignition ON, monitor live sensor output (voltage or resistance) while moving seat
Wiggle test: move harness/connector while watching live data for intermittent changes
Measure reference voltage and ground at the sensor connector

Signal parameters

Reference supply: typically 5 V (sometimes 12 V) — verify per vehicle spec
Sensor output: variable analog voltage proportional to seat position (approx. 0.5–4.5 V typical over travel)
Open-circuit: infinite/OL resistance between sensor output and module input
Short-to-ground: near 0 V on output; short-to-Vref: near reference voltage
Resistance-type sensors: resistance value should change smoothly with seat movement (no abrupt jumps)

Diagnostic algorithm

Retrieve freeze-frame data and any additional DTCs. Note when fault occurs (seat movement, ignition on, crash stored).
Follow service manual safety steps: disable battery and SRS systems if required before working under the seat.
Perform a visual inspection of the seat rails, sensor and wiring harness for damage, corrosion, or water entry.
Reconnect battery / enable diagnostics. With an appropriate scan tool, monitor seat position sensor live data or voltage while an assistant moves the seat through its full travel.
Check for stability: perform a wiggle test on the harness and connectors while watching live data for intermittent jumps or dropouts.
With ignition ON, measure reference voltage and ground at the sensor connector. Compare to manufacturer spec (commonly ~5 V).
Measure sensor output voltage (or resistance) across full travel. Look for smooth, monotonic change. If output is stuck, open, or noisy, suspect sensor or wiring.
If sensor output is abnormal, disconnect sensor and check continuity/resistance of wiring back to the module. Repair opens/shorts as needed.
If wiring and connectors are good but sensor output remains abnormal, replace the seat position sensor. Retest.
If replacement sensor still fails, suspect module fault — verify inputs at module, check for correct software/calibration and replace or reprogram module per factory instructions.
Clear codes, perform seat learn/calibration if required, and road-test/operate seat through cycles to confirm repair.

Likely causes

Wiring damage or broken conductor in the harness under the seat (most common)
Connector corrosion or poor pin contact at seat/base connector
Internal failure of the seat position sensor
Intermittent contact caused by seat movement (wiring routed across seat rails)
Module fault or incorrect calibration (less common)

Fault status

⚠️ Status

Seat position sensor circuit malfunction detected — signal out of range, open/short or intermittent. May affect seat memory and occupant classification/airbag functions. Inspect harness, connector, sensor and module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5 - 2.0 hours