B2152

Code

Other B — Body

Seat Rear Vertical Motor Position Out of Range

Brand: Other

Type: B — Body

Views: UK: 22 EN: 33 RU: 25

AI status

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Page language: EN

Causes

Faulty rear seat vertical position sensor (potentiometer/encoder)
Rear seat vertical adjuster motor failure or excessive resistance
Open, shorted, or corroded wiring/connectors in the motor or sensor circuit
Mechanical binding or obstruction in seat track/actuator
Poor ground or low battery/voltage supply to motor/sensor
Faulty seat control switch or body control module (BCM)

Symptoms

Rear seat vertical adjustment will not move or moves intermittently
Seat stuck in one vertical position or moves to an extreme position
Audible motor noise without movement or grinding noises
Instrument cluster/BCM displays a seat adjustment fault or stores DTC B2152
Seat position memory functions may fail

What to check

Use a scan tool to read DTCs and freeze-frame data; note if code is current or historic
Visually inspect seat tracks, actuator and connectors for damage, debris or binding
Check battery voltage (engine off and cranking) and ensure proper vehicle voltage (~12V)
Inspect fuses and relays for the seat circuit
Wiggle wiring harness at seat while operating switch to check for intermittent faults
Verify connector pins are clean and fully seated; check for corrosion or bent pins

Signal parameters

Nominal supply voltage to motor: ~12 V (vehicle battery voltage range 11–14 V)
Position sensor output: typically 0–5 V analog (should change smoothly as seat moves); expect stable mid-range at rest for mid position
Motor coil resistance: low ohms (varies by design) — large or infinite resistance indicates open circuit
Control signal may be PWM when motor is commanded — presence of PWM on control wire when operating is expected

Diagnostic algorithm

Read and record all stored DTCs and freeze-frame data with a scan tool; attempt to reproduce the fault. 2) Visually inspect the rear seat assembly, tracks and connectors for mechanical obstruction, damage or debris that could bind the actuator. 3) Verify battery and system voltage; check relevant fuses/relays. 4) With ignition on, command the seat up/down while monitoring position sensor voltage; verify the sensor output changes smoothly and remains within 0–5 V range. 5) Check wiring continuity between the seat connector and BCM; inspect for shorts to ground or battery. 6) Backprobe motor supply and control wires while commanding movement: confirm ~12 V supply and control/PWM signal present. 7) Measure motor coil resistance; an open or extremely high resistance suggests a failed motor. 8) If wiring, supply, and control signals are good but sensor output is invalid, remove seat trim and test/replace the position sensor. 9) If motor does not run when directly supplied with 12 V (after isolating controls and following safety procedures), replace or rebuild motor/actuator. 10) After repairs, clear codes, perform any required seat calibration/relearn, and verify proper operation and no return of DTC.

Likely causes

Position sensor drift or internal failure
Wiring damage at the seat (pinch points, broken wires)
Motor worn or seized due to debris or wear
Connector corrosion or poor ground at seat module

Fault status

⚠️ Status

Stored DTC B2152 — Seat rear vertical motor/position sensor output is out of expected range. Seat vertical adjuster may be inoperative until fault is addressed.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours