B2146

Code

Other B — Body

Seat Recline Motor Position Out of Range

Brand: Other

Type: B — Body

Views: UK: 23 EN: 31 RU: 35

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Page language: EN

Causes

Faulty seat recline position sensor (potentiometer/Hall sensor)
Open/short or high-resistance wiring/connectors between seat and control module
Failed seat recline motor or motor driver in the seat module
Mechanical binding or obstruction in the recline mechanism
Loss of reference supply or ground to the sensor/motor
Software/calibration error in seat control module or interrupted learn cycle

Symptoms

Seat back will not recline or return to memory positions
Seat movement is erratic, jumps, or moves only part way
Seat position does not match switch input or memory settings
DTC B2146 stored and possibly other seat related codes present
Occasional loss of seat power or inability to move seat in recline axis

What to check

Scan for stored codes and freeze-frame data; note related seat/body codes
Inspect seat-back area and under-seat wiring harness for damage, pinched wires, or loose connectors
Visually inspect connector pins and perform wiggle test while operating recline switch (observe scanner live data)
Confirm fuses and relays for seat circuits are intact
Ensure battery voltage is stable during tests (no low-voltage conditions)
Listen for motor noise when recline switch is operated to determine if motor is attempting to move

Signal parameters

Supply voltage to motor/control: ~12 V (key ON)
Ground: direct chassis ground continuity
Position sensor output: variable DC voltage across travel (commonly ~0.5–4.5 V or 0–5 V depending on design)
Position sensor resistance or voltage should change smoothly across full recline travel (no dead spots)
Motor control may be PWM-driven; typical PWM freq range ~100–300 Hz (manufacturer-specific)

Diagnostic algorithm

Read and record all stored codes and live data from the seat/Body Control Module (BCM). Note freeze frame and any related codes.
Safety first: if working near seat-belt pretensioners or airbags, disable the battery and follow manufacturer wait time before disconnecting connectors.
Visually inspect connector(s) at the seat motor/module and position sensor for corrosion, bent pins, pushed-out terminals or poor contact. Repair as needed.
With connector connected, backprobe position sensor wires and observe live voltage while operating recline switch. Confirm sensor output changes smoothly across full travel. If erratic or flat, suspect sensor or wiring.
Check for proper 12 V supply and ground at the motor/control connector with switch operated. If no supply, trace upstream fuse, relay, and switch.
Wiggle wiring harness while operating recline to check for intermittent open/short. Repair any wiring faults.
If power/ground/pot signals are correct but position reading is out of range, inspect the recline mechanism for mechanical binding or excessive play; free or repair as required.
If motor runs but position reading does not change, replace the position sensor or recline motor assembly per manufacturer procedure.
If wiring and mechanical checks are good, test or replace the seat control module/motor driver. Reprogram or perform seat position relearn/calibration using OEM scan tool if required.
After repairs, clear codes, perform relearn/calibration if required, and verify operation across full travel; confirm code does not return during test cycle.