AIR CONDITIONING SYSTEM PTC Heater Circuit

DESCRIPTION

The air conditioning amplifier assembly sends operation signals to the PTC HTR relays when quick heater assembly (PTC heater) operation conditions are met. Based on the signals from the air conditioning amplifier assembly, the PTC HTR relays turn on, and power is supplied to the quick heater assembly (PTC heater) installed in the air conditioning radiator assembly.

Quick Heater Assembly (PTC Heater) Operation Condition
Control ECU Condition
Air Conditioning Amplifier Assembly Blower motor on
Temperature set to MAX HOT
ECO mode switch (eco switch assembly) off

IDH terminal signal less than 1 V

(Inverter with converter assembly overload not detected)
Engine coolant temperature approximately 50°C or lower
Ambient temperature 10°C or lower

WIRING DIAGRAM

A01V0JNE03

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    5. According to the display on the GTS, perform the Active Test.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Heater Active Level PTC heater Min.: 0, Max.: 3 -
      OK
      Heater Active Level changes normally.

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. INSPECT PTC HEATER RELAY (PTC HTR NO. 1, NO. 2 OR NO. 3 RELAY)


    1. Inspect the PTC heater relay (PTC HTR NO. 1, NO. 2 and NO. 3 relay) Click here.


    NG

    REPLACE PTC HEATER RELAY (PTC HTR NO. 1, NO. 2 OR NO. 3 RELAY)

    OK

  3. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - AUXILIARY BATTERY AND IG1 NO. 1 RELAY)


    1. Remove the PTC heater relay (PTC HTR NO. 1, NO. 2 and NO. 3 relay) from the No. 2 engine room relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      PTC1
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Always 11 to 14 V
      Relay terminal 1- Body ground Ignition switch ON (IG) 11 to 14 V
      PTC2
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Always 11 to 14 V
      Relay terminal 1- Body ground Ignition switch ON (IG) 11 to 14 V
      PTC3
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Always 11 to 14 V
      Relay terminal 1- Body ground Ignition switch ON (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Remove the PTC heater relay (PTC HTR NO. 1, NO. 2 and NO. 3 relay) from the No. 2 engine room relay block.

    2. Disconnect the F29 air conditioning amplifier assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      PTC1
      Tester Connection Condition Specified Condition
      Relay terminal 2- F29-40 (PTC1) Always Below 1 Ω
      Relay terminal 2- Body ground Always 10 kΩ or higher
      PTC2
      Tester Connection Condition Specified Condition
      Relay terminal 2- F29-39 (PTC2) Always Below 1 Ω
      Relay terminal 2- Body ground Always 10 kΩ or higher
      PTC3
      Tester Connection Condition Specified Condition
      Relay terminal 2- F29-3 (PTC3) Always Below 1 Ω
      Relay terminal 2- Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - QUICK HEATER ASSEMBLY)


    1. Remove the PTC heater relay (PTC HTR NO. 1, NO. 2 and NO. 3 relay) from the No. 2 engine room relay block.

    2. Disconnect the A25 quick heater assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      PTC1
      Tester Connection Condition Specified Condition
      Relay terminal 3 - A25-2 (B) Always Below 1 Ω
      Relay terminal 3 - Body ground Always 10 kΩ or higher
      PTC2
      Tester Connection Condition Specified Condition
      Relay terminal 3 - A25-1 (B) Always Below 1 Ω
      Relay terminal 3 - Body ground Always 10 kΩ or higher
      PTC3
      Tester Connection Condition Specified Condition
      Relay terminal 3 - A25-3 (B) Always Below 1 Ω
      Relay terminal 3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT QUICK HEATER ASSEMBLY


    1. Inspect the quick heater assembly Click here.


    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPLACE QUICK HEATER ASSEMBLY Click here