P0846 — Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range/Performance

CAUTIONIs it safe to drive? Usually driveable, but get it diagnosed soon; it can worsen, hurt fuel economy, or fail emissions if ignored.

What P0846 means

The trans fluid pressure sensor/switch 'B' voltage is out of the expected range, so the TCM can't trust line pressure data. Leads to harsh shifts or limp mode.

Most likely causes (in order)

  1. Transmission fluid pressure sensor/switch failed ($80-250)
  2. Low/dirty trans fluid
  3. Valve body / wiring issue
  4. Internal pressure-control fault

Symptoms you might notice

What to check first

Check fluid level/condition and the pressure sensor signal; inspect the harness. Common on Nissan/Infiniti and others.

Repair cost & difficulty

Parts
$80-400
Labor
1-3 hr
Difficulty
DIY-friendly

Related codes

P0845P0840P0847
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