Air Conditioning System (For Sedan) Ptc Heater Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (A/C, HTR SUB1, HTR SUB2)

INSPECT NO. 3 HEATER CONTROL KNOB

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AIR CONDITIONING AMPLIFIER)

CHECK HARNESS AND CONNECTOR (No. 3 HEATER CONTROL KNOB - AIR CONDITIONING AMPLIFIER)

INSPECT AIR CONDITIONING AMPLIFIER

INSPECT PTC HEATER RELAY (HTR SUB1, HTR SUB2, HTR SUB3)

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

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

INSPECT PTC HEATER ASSEMBLY

CHECK HARNESS AND CONNECTOR (BATTERY - PTC HEATER RELAY)

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Remove the A/C fuse from the main body ECU.
   

2. Remove the HTR SUB1 and HTR SUB2 fuses from the engine room relay block.
   

3. Measure the resistance.
   

   Standard resistance:

   Tester Item	Specified Condition
   A/C fuse	Below 1 Ω
   HTR SUB 1 fuse	Below 1 Ω
   HTR SUB 2 fuse	Below 1 Ω

4. Reinstall the A/C fuse.
   

5. Reinstall the HTR SUB1 and HTR SUB2 fuses.
   

1. Remove the No. 3 heater control knob.
   

2. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   3 (IG+) - 6 (B)	Max hot position	Below 1 Ω
   3 (IG+) - 6 (B)	Other than max hot position	10 kΩ or higher

3. Reinstall the No. 3 heater control knob.
   

1. Disconnect the E6 No. 3 heater control knob connector.
   

2. Measure the voltage.
   

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   E6-3 (IG+) - Body ground	Ignition switch ON	11 to 14 V

3. Reconnect the No. 3 heater control knob connector.
   

1. Disconnect the E6 No. 3 heater control knob connector.
   

2. Disconnect the E9 air conditioning amplifier connector.
   

3. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   E6-6 (B) - E9-14 (HEAT)	Below 1 Ω

4. Reconnect the No. 3 heater control knob connector.
   

5. Reconnect the air conditioning amplifier connector.
   

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

2. Turn the ignition switch ON.
   

3. When the PTC heater operating conditions are met (engine at idling speed or faster, ambient temperature is 10°C (50°F) or less, engine coolant temperature is 65°C (149°F) or less, and No. 3 heater control knob setting is MAX HOT), turn the blower switch to the Lo setting.
   

4. Wait 30 seconds.
   

5. Measure the voltage.
   

   Standard voltage:

   Tester Connection	Specified Condition
   E9-9 (PTC1) - Body ground	11 to 14 V
   E9-10 (PTC2) - Body ground	11 to 14 V
   E9-12 (PTC3) - Body ground	11 to 14 V

6. Reinstall the air conditioning amplifier.
   

1. Remove the HTR SUB1 relay from the engine room relay block.
   

2. Remove the HTR SUB2 and HTR SUB3 relays from the engine room sub relay block.
   

3. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

4. Reinstall the HTR SUB1 relay.
   

5. Reinstall the HTR SUB2 and HTR SUB3 relays.
   

1. Remove the HTR SUB1 relay from the engine room R/B.
   

2. Remove the HTR SUB2 and HTR SUB3 relays from the engine room R/B No. 2.
   

3. Turn the ignition switch ON.
   

4. When the PTC heater operating conditions are met (engine at idling speed or faster, ambient temperature is 10°C (50°F) or less, engine coolant temperature is 65°C (149°F) or less, and No. 3 heater control knob setting is MAX HOT), turn the blower switch to the Lo setting.
   

5. Wait 30 seconds.
   

6. Measure the voltage.
   

   Standard voltage.:

   Tester Connection	Specified Condition
   HTR SUB1-2 - Body ground	11 to 14V
   HTR SUB2-2 - Body ground	11 to 14V
   HTR SUB3-2 - Body ground	11 to 14V

7. Reinstall the HTR SUB1 relay.
   

8. Reinstall the HTR SUB2 and HTR SUB3 relays.
   

1. Remove the HTR SUB1 relay from the engine room R/B.
   

2. Remove the HTR SUB2 and HTR SUB3 relays from the engine room R/B No. 2.
   

3. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   HTR SUB1-1 - Body ground	Below 1 Ω
   HTR SUB2-1 - Body ground	Below 1 Ω
   HTR SUB3-1 - Body ground	Below 1 Ω

4. Reinstall the HTR SUB1 relay.
   

5. Reinstall the HTR SUB2 and HTR SUB3 relays.
   

1. Disconnect the A17 PTC heater assembly connector.
   

2. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   1 - 2	Below 1 Ω
   1 - 3	Below 1 Ω
   2 - 3	Below 1 Ω

3. Reconnect the PTC heater assembly connector.
   

1. Remove the HTR SUB1 relay from the engine room R/B.
   

2. Remove the HTR SUB2 and HTR SUB3 relays from the engine room R/B No. 2.
   

3. Measure the voltage.
   

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   HTR SUB1-5 - Body ground	Always	11 to 14 V
   HTR SUB2-5 - Body ground	Always	11 to 14 V
   HTR SUB3-5 - Body ground	Always	11 to 14 V

4. Reinstall the HTR SUB1 relay.
   

5. Reinstall the HTR SUB2 and HTR SUB3 relays.
   

1. Remove the HTR SUB1 relay from the engine room R/B.
   

2. Remove the HTR SUB2 and HTR SUB3 relays from the engine room R/B No. 2.
   

3. Disconnect the A17 PTC heater assembly connector.
   

4. Measure the resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   HTR SUB1-3 - A17-2 (B)	Below 1 Ω
   HTR SUB2-3 - A17-3 (B)	Below 1 Ω
   HTR SUB3-3 - A17-1 (B)	Below 1 Ω

5. Reinstall the HTR SUB1 relay.
   

6. Reinstall the HTR SUB2 and HTR SUB3 relays.
   

7. Reconnect the PTC heater assembly connector.