B1D59

Code

Generic B — Body

Seat position sensor circuit - high voltage

Brand: Generic

Type: B — Body

Views: UK: 9 EN: 11 RU: 10

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Short to battery/ignition voltage on the sensor signal or supply wire
Damaged or chafed wiring harness (pinched at seat rails or connectors)
Corroded or poorly seated connector terminals
Internal short/failure of the seat position sensor (potentiometer or Hall sensor)
Poor or missing ground at seat module or sensor return
Water intrusion or contamination at the seat connector or sensor

Symptoms

SRS/airbag or occupant classification warning lamp illuminated
Seat position memory or seat adjustment faults (on equipped vehicles)
Occupant detection/airbag suppression may be disabled or set to a default state
Diagnostic trouble code B1D59 stored with freeze-frame data
Intermittent or permanent loss of correct seat-position reporting to modules

What to check

Use a scan tool to read stored codes, freeze-frame and history; clear codes and confirm repeatability
Visually inspect seat wiring, connectors and seat-rail areas for damage, pinching, corrosion or water ingress
Check connector mating condition and terminal integrity; reseat connectors
With ignition ON (and ignition/airbag systems powered per manufacturer safe procedures), measure voltage at the sensor connector: supply, signal and ground pins
Perform a wiggle test while monitoring live data or voltage for intermittent short
Disconnect the sensor then measure voltage on the harness side to determine if short is in sensor or wiring/module

Signal parameters

Typical reference/supply: 5 V (many sensor circuits) — verify manufacturer spec
Expected signal range: ~0.1–4.9 V variable (for potentiometer-type seat position sensors) or valid Hall output per spec
High-voltage fault threshold: signal/supply above manufacturer maximum (commonly >5.5 V) triggers DTC
Open/short thresholds: near 0 V indicates open/short-to-ground; near battery voltage (≈12 V) indicates short-to-battery

Diagnostic algorithm

Retrieve codes and freeze-frame data with a scan tool; note conditions when code set (ignition state, vehicle speed, recent seat movement)
Visually inspect harness, connectors and seat mounting/rail area for damage, corrosion, or water; repair obvious faults
With ignition ON (follow safe service procedures for SRS circuits), backprobe sensor connector and record supply, signal and ground voltages and compare to manufacturer specs
If signal voltage is high with sensor connected, disconnect the sensor and measure voltage on the harness side; if voltage remains high, suspect wiring short to battery or module fault
If harness voltage is normal with sensor disconnected, test/replace the seat position sensor (bench test or measure sensor resistance/voltage while operating seat)
Perform continuity and short-to-voltage tests on the signal and supply wires (resistance to battery + and ground) to locate short
Repair or replace damaged wiring, terminals, or sensor as required; ensure good grounds and dry/secure connectors
Clear codes and perform a functional test/road test; verify code does not return and that occupant classification/SRS indicators and seat functions operate correctly

Likely causes

Short to battery/ignition on signal or supply wiring (most common)
Corroded/loose connector at seat sensor
Wiring abrasion at seat rail where harness moves
Internal sensor short (wear or contamination)
Module internal failure or bad ground

Fault status

⚠️ Status

Seat position sensor circuit voltage above allowed threshold. ECU logged high-voltage fault on seat position input; occupant classification/airbag behavior may be affected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours