OBD Guide

P1841

Automatic Transmission Fluid Pressure Switch 1

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Incorrect gear shifting
  • Hard gear shifts
  • Automatic transmission goes into emergency mode
  • Check Engine Light Illuminates
  • Decreased fuel efficiency

Causes

  • Transmission fluid pressure sensor malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Low or contaminated transmission fluid
  • Transmission control module (TCM) problems

How to Fix

  1. Check the level and condition of the transmission fluid
  2. Visually inspect the sensor wiring and connectors
  3. Check sensor resistance and reference voltage
  4. If necessary, replace the pressure sensor
  5. Check the operation of the automatic transmission after repair

Related codes

Error P1841 by Vehicle Brand