AIR CONDITIONING SYSTEM 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

A01ER7CE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT PTC HEATER RELAY (PTC HTR1)

    A01ERM6E07

    1. Remove the PTC HTR1 relay from the engine room 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 between terminals 1 and 2 10 kΩ or higher
      Battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE PTC HEATER RELAY

    OK

  2. INSPECT PTC HEATER RELAY (PTC HTR2)

    A01ERM6E05

    1. Remove the PTC HTR2 relay from the engine room 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 between terminals 1 and 2 10 kΩ or higher
      Battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE PTC HEATER RELAY

    OK

  3. INSPECT PTC HEATER RELAY (PTC HTR3)

    A01ERM6E06

    1. Remove the PTC HTR3 relay from the engine room 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 between terminals 1 and 2 10 kΩ or higher
      Battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE PTC HEATER RELAY

    OK

  4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    A01ERO1E01

    1. 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
      E36-27 (PTC1) - Body ground

      • Engine switch on (IG)

      • Temperature setting: Hi

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

      • Engine coolant temperature: 73°C (163.4°F) or less

      • Blower switch on

      		 11 to 14 V
      E36-26 (PTC2) - Body ground
      E36-35 (PTC3) - Body ground

    NG

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND) Click here

    OK

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

    A01ERMKE01

    1. Remove the PTC heater relays from the engine room relay block.

    2. Disconnect the E33 quick heater assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      PTC HTR2 terminal 3 - E33-1 (B) Always Below 1 Ω
      PTC HTR1 terminal 3 - E33-2 (B)
      PTC HTR3 terminal 3 - E33-3 (B)
      PTC HTR2 terminal 3 - Body ground Always 10 kΩ or higher
      PTC HTR1 terminal 3 - Body ground
      PTC HTR3 terminal 3 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT QUICK HEATER ASSEMBLY

    A01ESB9E03

    1. Disconnect the E33 and E34 quick heater assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E33-1 (B) - E34-1 (E) Always Below 1 kΩ
      E33-2 (B) - E34-1 (E)
      E33-3 (B) - E34-2 (E)

    NG

    REPLACE QUICK HEATER ASSEMBLY Click here

    OK

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


    1. A01EO36E01

      Disconnect the E34 quick heater assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E34-1 (E) - Body ground Always Below 1 Ω
      E34-2 (E) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)

    A01ERP4E02

    1. Disconnect the E36 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E36-27 (PTC1) - Body ground Always Below 200 Ω
      E36-26 (PTC2) - Body ground
      E36-35 (PTC3) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here