Powertrain, generic · Transmission

P082B Gear Lever X Position Sensor 1 Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

Gear lever X and Y position sensors detect a selector's position in two directions: on an H-gate shift and select direction (a LuK patent uses two sensors about 90° apart), on a shift-by-wire lever its two axes. P0820 covers the whole X-Y circuit, P0821–P0824 and P082A–P082F sensor 1, P089A–P08A3 a redundant sensor 2. GM uses P082A–P082F on its electronic range selector (2019 tables, Cadillac XT4, 2025): a Hall sensor delivers a PWM signal, measured as duty cycle. P082B means the duty cycle of X sensor 1 is too low – the signal stays near 0 %, a short to ground or a sensor without supply. GM sets it below 17 % with 3 of 4 samples of 25 ms (2019) or below 5 % with 10 of 12 samples (2025), type B with the MIL after two trips. Sensor 2 then takes over; if both fail, park is selected, as GM's patent describes.

Likely causes

Signal wire shorted to ground
Sensor supply open
Sensor in the selector assembly faulty
Control module

Symptoms

  • Check engine lamp after two trips (GM)
  • 'Shift to park' message or transmission warning
  • Range selection restricted; with both sensors failed the vehicle goes to park

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

gear lever position sensorelectronic range selectorsensor wiringtransmission control module

Related codes

P082AP082CP082EP0821P0823

References: gsi.ext.gm.com, gsi.ext.gm.com, patents.google.com.