AIR CONDITIONING SYSTEM PTC Heater Circuit

DESCRIPTION

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

Quick Heater Assembly Operation Condition
Control ECU Condition
Air Conditioning Amplifier Assembly Power switch on (READY)
ECO mode switch off
Blower switch: on
Temperature settings: MAX HOT

IDH terminal signal less than 1 V

(Inverter with converter assembly overload not detected)

  • FC coolant temperature 65°C (149°F), or lower (3 PTC heater relays operating)

  • FC coolant temperature 70°C (158°F), or lower (2 PTC heater relays operating)

  • FC coolant temperature 75°C (167°F), or lower (A PTC heater relay operating)
Ambient temperature 10°C (50°F) or lower

WIRING DIAGRAM

A01MJ0YE02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Check the operation by referring to the table below.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Heater Active Level Quick heater assembly Min.: 0, Max.: 3 -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Heater Active Level
      OK
      Heater Active Level changes normally.
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Remove the PTC heater relays.

    2. Inspect the PTC heater relays.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE PTC HEATER RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - POWER SOURCE CIRCUIT)


    1. A01MGI6C02
      *1 No. 2 Motor Compartment Relay Block
      *2 PTC NO. 1 Relay Holder
      *3 PTC NO. 2 Relay Holder
      *4 PTC NO. 3 Relay Holder

      Remove the PTC heater relays.

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

      Standard Voltage
      PTC NO. 1
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Power switch off 11 to 14 V
      Relay terminal 1 - Body ground Power switch off Below 1 V
      Relay terminal 1 - Body ground Power switch on (IG) 11 to 14 V
      PTC NO. 2
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Power switch off 11 to 14 V
      Relay terminal 2 - Body ground Power switch off Below 1 V
      Relay terminal 2 - Body ground Power switch on (IG) 11 to 14 V
      PTC NO. 3
      Tester Connection Switch Condition Specified Condition
      Relay terminal 5 - Body ground Power switch off 11 to 14 V
      Relay terminal 1 - Body ground Power switch off Below 1 V
      Relay terminal 1 - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    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 relays.

    2. Disconnect the G43 air conditioning amplifier assembly connector.

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

      Standard Resistance
      PTC NO. 1
      Tester Connection Condition Specified Condition
      Relay terminal 2 - G43-15 (PTC1) Always Below 1 Ω
      Relay terminal 2 or G43-15 (PTC1) - Body ground Always 10 kΩ or higher
      PTC NO. 2
      Tester Connection Condition Specified Condition
      Relay terminal 1 - G43-16 (PTC2) Always Below 1 Ω
      Relay terminal 1 or G43-16 (PTC2) - Body ground Always 10 kΩ or higher
      PTC NO. 3
      Tester Connection Condition Specified Condition
      Relay terminal 2 - G43-3 (PTC3) Always Below 1 Ω
      Relay terminal 2 or G43-3 (PTC3) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the PTC heater relays.

    2. Disconnect the A42 quick heater assembly connector.

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

      Standard Resistance
      PTC NO. 1
      Tester Connection Condition Specified Condition
      A42-1 (B) - Relay terminal 3 Always Below 1 Ω
      A42-1 (B) or Relay terminal 3 - Body ground Always 10 kΩ or higher
      PTC NO. 2
      Tester Connection Condition Specified Condition
      A42-2 (B) - Relay terminal 3 Always Below 1 Ω
      A42-2 (B) or Relay terminal 3 - Body ground Always 10 kΩ or higher
      PTC NO. 3
      Tester Connection Condition Specified Condition
      A42-3 (B) - Relay terminal 3 Always Below 1 Ω
      A42-3 (B) or Relay terminal 3 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (QUICK HEATER ASSEMBLY - BODY GROUND)


    1. Disconnect the A43 and A44 quick heater assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A43-1 (E) - Body ground Always Below 1 Ω
      A44-1 (E) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT QUICK HEATER ASSEMBLY


    1. Remove the quick heater assembly.

      Click here

    2. Inspect the quick heater assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPLACE QUICK HEATER ASSEMBLY Click here