Air Conditioning System (For Manual Air Conditioning System) Ptc Heater Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (PTC1, PTC2)

INSPECT AIR MIX CONTROL KNOB (MAX HOT SWITCH)

CHECK WIRE HARNESS (AIR MIX CONTROL KNOB - BATTERY)

CHECK WIRE HARNESS (AIR MIX CONTROL KNOB - AIR CONDITIONING AMPLIFIER)

INSPECT PTC HEATER RELAY (Marking: PTC NO. 1, PTC NO. 2)

CHECK AIR CONDITIONING AMPLIFIER

CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - PTC HEATER RELAY)

CHECK WIRE HARNESS (PTC HEATER RELAY - BODY GROUND)

CHECK WIRE HARNESS (PTC HEATER - PTC HEATER RELAY)

CHECK WIRE HARNESS (BATTERY - PTC HEATER RELAY)

CHECK PTC HEATER

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Remove the PTC1 and PTC2 H-fuses from the engine room No. 2 relay block.
   

2. Measure the resistance of the H-fuses.
   

   Standard resistance:

   Below 1 Ω
   

1. Remove the air mix control knob.
   

2. Measure the resistance of the knob.
   

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   E29-2 (B) - E29-8 (E)	Max hot position	Below 1 Ω
   E29-2 (B) - E29-8 (E)	Other than max hot position	10 kΩ or higher

1. Disconnect the E29 control knob connector.
   

2. Measure the voltage of the wire harness side connector.
   

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   E29-2 (B) - Body ground	Ignition switch on (IG)	10 to 14 V

1. Disconnect the E29 control knob connector.
   

2. Disconnect the E43 amplifier connector.
   

3. Measure the resistance of the wire harness side connectors.
   

   Standard resistance:

   Tester Connection	Specified Condition
   E29-8 (E) - E43-14 (HEAT)	Below 1 Ω

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

2. Measure the resistance of the relays.
   

   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)

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

2. Turn the ignition switch on (IG).
   

3. When the PTC heater operating conditions are met (engine at idle speed or faster, ambient temperature is 10°C (50°F) or less, engine coolant temperature is 65°C (149°F) or less, air mix control knob setting is MAX HOT), turn the blower switch to the Lo setting.
   

4. Measure the voltage of the wire harness side connectors.
   

   Standard voltage:

   Tester Connection	Specified Condition
   E43-9 (PTC1) - Body ground	10 to 14 V
   E43-10 (PTC2) - Body ground	10 to 14 V

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

2. Turn the ignition switch on (IG).
   

3. When the PTC heater operating conditions are met (engine at idle speed or faster, ambient temperature is 10°C (50°F) or less, engine coolant temperature is 65°C (149°F) or less, air mix control knob setting is MAX HOT), turn the blower switch to the Lo setting.
   

4. Measure the voltage of the wire harness side connectors
   

   Standard voltage:

   Tester Connection	Specified Condition
   No. 1 PTC heater relay terminal 1 - Body ground	10 to 14 V
   No. 2 PTC heater relay terminal 2 - Body ground	10 to 14 V

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

2. Measure the resistance of the wire harness side connectors.
   

   Standard resistance:

   Tester Connection	Specified Condition
   No. 1 PTC heater relay terminal 2 - Body ground	Below 1 Ω
   No. 2 PTC heater relay terminal 1 - Body ground	Below 1 Ω

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

2. Measure the resistance of the wire harness side connectors.
   

   Standard resistance:

   Tester Connection	Specified Condition
   No. 1 PTC heater relay terminal 3 - A29-3 (B)	Below 1 Ω
   No. 2 PTC heater relay terminal 3 - A29-2 (B)	Below 1 Ω
   No. 1 PTC heater relay terminal 3 - A29-1 (B)	Below 1 Ω

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

2. Measure the voltage of the wire harness side connectors.
   

   Standard voltage:

   Tester Connection	Specified Condition
   No. 1 PTC heater relay terminal 5 - Body ground	10 to 14 V
   No. 2 PTC heater relay terminal 5 - Body ground	10 to 14 V

1. After replacing the PTC heater with a normal one, check that the PTC heater function operates normally.
   

   OK:

   PTC heater function operates normally.