Powertrain, generic (extended)

P2802 Transmission Range Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2802 means the B signal of the range sensor sits too low, usually a ground short or a duty cycle collapsing toward zero. GM's tables for 2020 and 2025 place the check in the engine module, which reads internal range sensor B on its own wire: a circuit impedance under 0.5 ohm to ground for 0.5 s within a one-second window sets the code as Type A, MIL in the first trip. Ford's 2024 summary sets it (P2800_84) on its six- and ten-speed automatics when the duty cycle drops below 8 %. Ford's hybrid sedans and the C-Max showed P2802 alongside P2800 once water had entered connectors (SSM 47790). P2803 is the high fault and P0707 the matching low fault of sensor A.

Likely causes

Signal wire of sensor B shorted to ground
Water or corrosion in a connector of the circuit
Range sensor output stage failed low

Symptoms

  • MIL or wrench lamp on
  • No start in Park, missing gear indication
  • Stop-start or shift functions restricted

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–700
Time0.5–3 h

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

Parts involved

transmission range sensor bwiring harnesstcm

Related codes

P2803P0707P2800P2805

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, static.nhtsa.gov.