AIR CONDITIONING SYSTEM PTC Heater Circuit

DTC Code DTC Name
PTC Heater Circuit

DESCRIPTION

PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

WIRING DIAGRAM

E200726E06

PROCEDURE

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

    1. E199507

      Remove the PTC NO.1, PTC NO.2 and PTC NO.3 relays from the engine room No. 2 relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3 - 5

      Battery voltage is not applied to terminals 1 and 2

      10 kΩ or higher

      Battery voltage is applied to terminals 1 and 2

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

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

    OK

  2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    1. E197830C04

      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected.

      Click here

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      G13-3 (PTC1) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 79°C (174°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      Below 1 V*

      G13-22 (PTC2) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 76°C (169°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      G13-4 (PTC3) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 73°C (163°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      G13-3 (PTC1) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 79°C (174°F) or less

      • Headlight dimmer switch off

      • Blower switch on

      11 to 14 V*

      G13-22 (PTC2) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 76°C (169°F) or less

      • Headlight dimmer switch off

      • Blower switch on

      G13-4 (PTC3) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 73°C (163°F) or less

      • Headlight dimmer switch off

      • Blower switch on
      Tip:

      *: After the measurement conditions are met, wait 30 seconds before performing measurements.

    Result

    Proceed to

    OK

    NG
    NG

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick here

    OK

  3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - AIR CONDITIONING AMPLIFIER)

    1. Remove the PTC heater relays from the engine room No. 2 relay block.

    2. Disconnect the G13 amplifier connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      PTC NO.1 relay terminal 1 - G13-3 (PTC1)

      Always

      Below 1 Ω

      PTC NO.2 relay terminal 1 - G13-22 (PTC2)

      PTC NO.3 relay terminal 1 - G13-4 (PTC3)

      PTC NO.1 relay terminal 1 - Body ground

      Always

      Below 1 Ω

      PTC NO.2 relay terminal 1 - Body ground

      PTC NO.3 relay terminal 1 - Body ground

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - QUICK HEATER)

    1. Remove the PTC heater relays from the engine room No. 2 relay block.

    2. Disconnect the G105 heater connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      PTC NO.1 relay terminal 3 - G105-2 (B)

      Always

      Below 1 Ω

      PTC NO.2 relay terminal 3 - G105-3 (B)

      PTC NO.3 relay terminal 3 - G105-1 (B)

      PTC NO.1 relay terminal 3 - Body ground

      Always

      Below 1 Ω

      PTC NO.2 relay terminal 3 - Body ground

      PTC NO.3 relay terminal 3 - Body ground

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - BATTERY AND BODY GROUND)

    1. E200727C02

      *1

      PTC NO.1 Relay

      *2

      PTC NO.2 Relay

      *3

      PTC NO.3 Relay

      *a

      Component without relay installed

      (Engine Room No. 2 Relay Block)

      Remove the PTC heater relays from the engine room No. 2 relay block.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      PTC NO.1 relay terminal 5 - Body ground

      Always

      11 to 14 V

      PTC NO.2 relay terminal 5 - Body ground

      PTC NO.3 relay terminal 5 - Body ground

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      PTC NO.1 relay terminal 2 - Body ground

      Always

      Below 1 Ω

      PTC NO.2 relay terminal 2 - Body ground

      PTC NO.3 relay terminal 2 - Body ground

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT QUICK HEATER ASSEMBLY

    1. Remove the quick heater assembly.

      Click here

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A-1 (B) - B-1 (E)

      Always

      Below 1 Ω

      A-2 (B) - B-1 (E)

      A-2 (B) - C-1 (E)

      A-3 (B) - C-1 (E)

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE QUICK HEATER ASSEMBLY

    Click here

    OK

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

    1. E255754C01

      *a

      Front view of wire harness connector

      (to Quick Heater Assembly)

      Disconnect the G103 and G104 quick heater connectors.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G103-1 (E) - Body ground

      Always

      Below 1 Ω

      G104-1 (E) - Body ground

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR