Powertrain, generic (extended)

P2160 Vehicle Speed Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2160 reports that speed signal B shows little or no activity although the vehicle is plainly moving. Which pickup carries the letter B is the manufacturer's choice. GM assigns P2160 to the transfer case output speed sensor of its four-wheel-drive models (table 18OBDG04): with a gear engaged, moderate pedal and torque, no braking and the transmission output turning, a raw sensor reading under 25 rpm for 4.5 seconds stores the code as Type B, so the MIL follows after two trips. A broken wire, a short to ground or a dead sensor are the usual reasons. P2161 covers dropouts and erratic readings, P2158/P2159 the circuit and plausibility of the same sensor. Four-wheel-drive and speed-dependent functions may be restricted.

Likely causes

Broken signal wire or short to ground between sensor B and the module
Speed sensor B itself delivers no pulses
Corroded or pushed-back pins at the sensor connector
Tone wheel loose or missing after transfer case or driveline work

Symptoms

  • Check engine lamp after two drives
  • Four-wheel-drive warning or 4WD modes unavailable
  • Speedometer or cruise control misbehaving on some models

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–350
Time0.5–2 h

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

Parts involved

vehicle speed sensor btransfer casewiring harness

Related codes

P2161P2158P2159P2162P0502

References: gsi.ext.gm.com, law.cornell.edu.