B1955

Code

Other B — Body

Seat Front Up/Down Potentiometer Feedback Circuit Open

Brand: Other

Type: B — Body

Views: UK: 20 EN: 28 RU: 21

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Page language: EN

Causes

Broken or disconnected wiring/connector to the seat up/down potentiometer
Open or failed seat position potentiometer (internal open)
Corroded or bent connector pins at the seat or module
Failed seat control module or BCM input circuit
Water ingress or physical damage to seat wiring harness (e.g., under seat)
Interference from aftermarket equipment or incorrect repairs

Symptoms

Seat up/down function inoperative or intermittent
Seat memory/auto-position may not operate correctly
Diagnostic trouble code B1955 stored
Possible seat position mismatch messages or warning lamp
Intermittent operation when moving seat or when vehicle goes over bumps

What to check

Read and record DTCs and freeze-frame data with a scan tool
Visual inspection of seat wiring, connectors, and harness routing under the seat
Back-probe the potentiometer connector to check reference voltage, signal, and ground
Measure continuity/resistance of wires from potentiometer to seat control module
Wiggle test wiring and connector while observing signal or operation
Check for water, corrosion, or physical damage at connectors and harness grommets

Signal parameters

Reference supply voltage: typically ~5.0 V (validate to manufacturer spec)
Potentiometer signal: varies smoothly across travel, typically ~0.5–4.5 V from one end to other
Ground: near 0 V (low-impedance ground)
Potentiometer total resistance: commonly 2–20 kΩ depending on design (measure and compare to manufacturer spec)
Open-circuit condition: OL or very high resistance; signal stuck at reference or 0 V indicates wiring/connection fault

Diagnostic algorithm

Verify the code: use a scan tool to read/record B1955 and any related codes; note freeze-frame and live data for the seat potentiometer.
Safety: if working near SRS components, disable the battery and follow manufacturer procedures/wait times before disconnecting connectors or working on the seat.
Visual inspection: check the seat area, connectors, and wiring harness for damage, corrosion, or water ingress; inspect harness where it flexes under the seat.
Back-probe connector: with ignition ON (but engine off per vehicle procedure), back-probe the potentiometer connector and confirm reference voltage (≈5 V), ground continuity, and the signal voltage presence.
Operate the seat while monitoring: while moving the seat up/down, watch the signal voltage or live-data. A healthy pot will show a smooth, continuous change; a jump to open or fixed voltage indicates an open/failed pot or broken wire.
Continuity/resistance check: with ignition OFF, disconnect connectors and measure continuity between the potentiometer connector and the seat control module for signal, reference, and ground. Check for short to ground or battery.
Wiggle test: with harness connected and back-probing, wiggle wiring and connectors to reproduce the fault; intermittent change points to broken wires or poor connector contact.
Isolate component: if wiring and connectors are good but signal is open, measure resistance across the potentiometer terminals per spec. Replace the potentiometer assembly if it shows open or out-of-range resistance.
Module check: if pot and harness test good, test/replace the seat control module input circuit following manufacturer diagnostics or consult wiring diagrams for module-level tests.
Repair and verify: repair wiring/replace connector or potentiometer as required, clear codes, and confirm proper operation and that B1955 does not return.