OBD Guide

P1818

Transmission Fluid Pressure Valve Position Switch-Drive Without Drive Ratio

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Incorrect gear shifting
  • Gear slip
  • Hard gear shifting
  • Check Engine light comes on
  • Reduced transmission efficiency

Causes

  • Pressure valve position sensor malfunction
  • Open or short circuit in the sensor circuit
  • Problems with the transmission control unit
  • Low transmission fluid level
  • Transmission fluid contamination

How to Fix

  1. Check the level and condition of the transmission fluid
  2. Check the integrity of the sensor circuit
  3. Check the operation of the pressure valve position sensor
  4. Check the transmission control unit for errors
  5. If necessary, replace the sensor or transmission fluid

Related codes

Error P1818 by Vehicle Brand