AIR CONDITIONING SYSTEM (for Manual 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.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

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

   
   
   1. 

      for 1AD-CCo:

      Table 1. Text in Illustration

      *1

      HTR SUB NO.1 Relay, HTR SUB NO.3 Relay

      *2

      HTR SUB NO.2 Relay

      
      

      1. Remove the HTR SUB NO.1, HTR SUB NO.2 and HTR SUB 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

   2. 

      for 1AD-DPF:

      Table 2. Text in Illustration

      *1	HTR SUB NO.3 Relay	*2	HTR SUB NO.2 Relay
      *3	HTR SUB NO.1 Relay	-	-

      
      

      1. Remove the HTR SUB NO.1, HTR SUB NO.2 and HTR SUB 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

   
   
   • OKClick here
   • NGClick here
2. Click here

   CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

   
   
   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 H10-9 (PTC1) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 75°C (167°F) or less Headlight dimmer switch off Blower switch off 11 to 14 V* H10-10 (PTC2) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 70°C (158°F) or less Headlight dimmer switch off Blower switch off H10-12 (PTC3) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 65°C (149°F) or less Headlight dimmer switch off Blower switch off H10-9 (PTC1) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 75°C (167°F) or less Headlight dimmer switch off Blower switch on Below 1 V* H10-10 (PTC2) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 70°C (158°F) or less Headlight dimmer switch off Blower switch on H10-12 (PTC3) - Body ground Engine running (1250 rpm or more) Temperature setting MAX HOT Outside temperature 10°C (50°F) or less Engine coolant temperature 65°C (149°F) or less Headlight dimmer switch off Blower switch on

      Table 3. Text in Illustration

      *1	Component with harness connected (Air Conditioning Amplifier Assembly)

      Tip:

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

   
   
   • OKClick here
   • NGClick here
3. Click here

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

   
   
   1. 

      for 1AD-CCo:

      Table 4. Text in Illustration

      *1

      Component without relay installed (Engine Room No. 2 Relay Block)

      *2

      Rear view of wire harness connector (to Air Conditioning Amplifier)

      
      

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

      2. Disconnect the H10 amplifier connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 2 - H10-9 (PTC1) Always Below 1 Ω HTR SUB NO.2 relay terminal 2 - H10-10 (PTC2) HTR SUB NO.3 relay terminal 1 - H10-12 (PTC3) HTR SUB NO.1 relay terminal 2 - Body ground Always 10 kΩ or higher HTR SUB NO.2 relay terminal 2 - Body ground HTR SUB NO.3 relay terminal 1 - Body ground

   2. for 1AD-DPF:

      
      
      1. 

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

         Table 5. Text in Illustration

         *1

         Component without relay installed (Engine Room No. 2 Relay Block)

         *2

         Rear view of wire harness connector (to Air Conditioning Amplifier)

      2. Disconnect the H46 amplifier connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 1 - H10-9 (PTC1) Always Below 1 Ω HTR SUB NO.2 relay terminal 2 - H10-10 (PTC2) HTR SUB NO.3 relay terminal 1 - H10-12 (PTC3) HTR SUB NO.1 relay terminal 1 - Body ground Always 10 kΩ or higher HTR SUB NO.2 relay terminal 2 - Body ground HTR SUB NO.3 relay terminal 1 - Body ground

   
   
   • OKClick here
   • NGClick here
4. Click here

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

   
   
   1. 

      1AD-CCo:

      
      

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

      2. Disconnect the A14 heater connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 5 - A14-1 (B) Always Below 1 Ω HTR SUB NO.2 relay terminal 5 - A14-2 (B) HTR SUB NO.3 relay terminal 5 - A14-3 (B) HTR SUB NO.1 relay terminal 5 - Body ground Always 10 kΩ or higher HTR SUB NO.2 relay terminal 5 - Body ground HTR SUB NO.3 relay terminal 5 - Body ground

         Table 6. Text in Illustration

         *A	Component without relay installed (Engine Room No. 2 Relay Block)
         *B	Front view of wire harness connector (to Quick Heater Assembly

   2. 

      1AD-DPF:

      
      

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

      2. Disconnect the A14 heater connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 3 - A14-2 (B) Always Below 1 Ω HTR SUB NO.2 relay terminal 5 - A14-1 (B) HTR SUB NO.3 relay terminal 5 - A14-3 (B) HTR SUB NO.1 relay terminal 3 - Body ground Always 10 kΩ or higher HTR SUB NO.2 relay terminal 5 - Body ground HTR SUB NO.3 relay terminal 5 - Body ground

         Table 7. Text in Illustration

         *A	Component without relay installed (Engine Room No. 2 Relay Block)
         *B	Front view of wire harness connector (to Quick Heater Assembly

   
   
   • OKClick here
   • NGClick here
5. Click here

   CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - BATTERY AND BODY GROUND)

   
   
   1. 

      for 1AD-CCo:

      
      

      1. 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 HTR SUB NO.1 relay terminal 3 - Body ground Always 11 to 14 V HTR SUB NO.2 relay terminal 3 - Body ground HTR SUB NO.3 relay terminal 3 - Body ground

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 1 - Body ground Always Below 1 Ω HTR SUB NO.2 relay terminal 1 - Body ground HTR SUB NO.3 relay terminal 2 - Body ground

         Table 8. Text in Illustration

         *A	Component without relay installed (Engine Room No. 2 Relay Block)

   2. 

      for 1AD-DPF:

      
      

      1. 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 HTR SUB NO.1 relay terminal 5 - Body ground Always 11 to 14 V HTR SUB NO.2 relay terminal 3 - Body ground HTR SUB NO.3 relay terminal 3 - Body ground

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

         Standard Resistance
         Tester Connection Condition Specified Condition HTR SUB NO.1 relay terminal 2 - Body ground Always Below 1 Ω HTR SUB NO.2 relay terminal 1 - Body ground HTR SUB NO.3 relay terminal 2 - Body ground

         Table 9. Text in Illustration

         *A	Component without relay installed (Engine Room No. 2 Relay Block)

   
   
   • OKClick here
   • NGClick here
6. Click here

   INSPECT QUICK HEATER ASSEMBLY

   
   
   1. 

      Remove the quick heater assembly connectors (Click here).

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

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

   
   
   • OKClick here
   • NGClick here
7. Click here

   CHECK HARNESS AND CONNECTOR (QUICK HEATER - BODY GROUND)

   
   
   1. 

      Disconnect the A15 heater connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A15-1 (E) - Body ground Always Below 1 Ω A15-2 (E) - Body ground

      Table 10. Text in Illustration

      *1	Front view of wire harness connector (to Quick Heater Assembly)

   
   
   • OKClick here
   • NGClick here
8. Click here

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

9. Click here

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

10. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

11. Click here

    REPLACE QUICK HEATER ASSEMBLYClick here