LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 127 (Engine Controls - System & Component Testing - 4-Cylinder) >> Engine Sensors & Switches >> Positive Temperature Coefficient Heater >> Echo

Positive Temperature Coefficient Heater: Echo

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2003 Toyota Tacoma, 2003 Toyota RAV4, 2003 Toyota Prius, 2003 Toyota Matrix, and 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove Positive Temperature Coefficient (PTC) heater along with heater core. See appropriate HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  2. To test PTC heater for continuity, using ohmmeter, check that continuity exists between each electrical terminal and ground terminal on PTC heater. See Fig 1. Replace PTC heater if continuity does not exist between any electrical terminal and ground terminal.
  3. To test PTC heater resistance, remove PTC heater from heater core. Place probe end of PTC heater and thermometer in container of water. Attach ohmmeter between electrical terminals on PTC heater.
  4. Heat water and note that resistance is within specification in relation to temperature. See PTC HEATER RESISTANCE  table. Replace PTC heater if resistance is not within specification.
    PTC HEATER RESISTANCE

    Temperature Ohms
    77°F (25°C) 4800-5200
    104°F (40°C) 2550-2850
    212°F (100°C) 260-340
    Fig 1: Checking PTC Heater Continuity (ECHO)
    G99A54429Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About LEMON Manuals