LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2020 >> ES 300h Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 219 (Heating / Air Conditioning System (Except Hybrid) - Diagnostic Codes & Symptom Tests) >> AIR CONDITIONING SYSTEM (for Gasoline Model) >> PTC Heater Circuit [06/2018 - ] >> Procedure

PTC Heater Circuit [06/2018 - ]: Procedure

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2024 Lexus ES 350, 2024 Lexus ES 250, 2023 Lexus ES 350, 2023 Lexus ES 250, and 2022 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT PTC HTR RELAY 
    1. Inspect the PTC HTR relays.

      Refer to ON-VEHICLE INSPECTION [06/2018 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE PTC HTR RELAY 

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE - PTC HTR RELAY) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      PTC HTR NO. 1 

      Tester Connection Condition Specified Condition
      3 (PTC HTR NO. 1 relay) - Body ground Engine switch off 11 to 14 V
      2 (PTC HTR NO. 1 relay) - Body ground Engine switch off Below 1 V
      2 (PTC HTR NO. 1 relay) - Body ground Engine switch on (IG) 11 to 14 V

      Standard Voltage

      PTC HTR NO. 2 

      Tester Connection Condition Specified Condition
      3 (PTC HTR NO. 2 relay) - Body ground Engine switch off 11 to 14 V
      2 (PTC HTR NO. 2 relay) - Body ground Engine switch off Below 1 V
      2 (PTC HTR NO. 2 relay) - Body ground Engine switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (PTC HTR RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY) 
    1. Disconnect the G39 and G40 air conditioning amplifier assembly connectors.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      PTC HTR NO. 1 

      Tester Connection Condition Specified Condition
      1 (PTC HTR NO. 1 relay) - G39-18 (PTC1) Always Below 1 Ω
      1 (PTC HTR NO. 1 relay) or G39-18 (PTC1) - Body ground Always 10 kΩ or higher

      Standard Resistance

      PTC HTR NO. 2 

      Tester Connection Condition Specified Condition
      1 (PTC HTR NO. 2 relay) - G40-10 (PTC2) Always Below 1 Ω
      1 (PTC HTR NO. 2 relay) or G40-10 (PTC2) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (PTC HTR RELAY - QUICK HEATER ASSEMBLY AND BODY GROUND) 
    1. Disconnect the H1 and H2 quick heater assembly connectors.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      PTC HTR NO. 1 

      Tester Connection Condition Specified Condition
      5 (PTC HTR NO. 1 relay) - H1-2 (B) Always Below 1 Ω
      5 (PTC HTR NO. 1 relay) - H2-1 (B) Always Below 1 Ω
      5 (PTC HTR NO. 1 relay) or H1-2 (B) - Other terminals and body ground Always 10 kΩ or higher
      5 (PTC HTR NO. 1 relay) or H2-1 (B) - Other terminals and body ground Always 10 kΩ or higher

      Standard Resistance

      PTC HTR NO. 2 

      Tester Connection Condition Specified Condition
      5 (PTC HTR NO. 2 relay) - H2-3 (B) Always Below 1 Ω
      5 (PTC HTR NO. 2 relay) or H2-3 (B) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. INSPECT QUICK HEATER ASSEMBLY 
    1. Remove the quick heater assembly.

      Refer to REMOVAL [06/2018 - ]

    2. Inspect the quick heater assembly.

      Refer to INSPECTION [06/2018 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [06/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - ] 

    Result: 

    NG 

    REPLACE QUICK HEATER ASSEMBLY. Refer to  REMOVAL [06/2018 - ] 

scientia non olet · About LEMON Manuals