Inspection Procedure

1. Remove the ECU-IG LH fuse from the cowl side junction block LH.
2. Remove the GLW PLG1 and GLW PLG2 H-fuse from the engine room No. 1 junction block.
3. Measure the resistance of the fuses.

Standard resistance 

NG: REPLACE FUSE 

OK: Go to next step 

1. Remove the A/C amplifier with its connectors still connected.
2. Turn the engine switch on (IG).
3. While the PTC operating conditions are met (engine is running at 850 rpm or more, ambient temperature is 3°C (37.4°F) or less, engine coolant temperature is 75°C (167°F) or less, A/C switch setting is MAX HOT), turn the blower switch to the Lo setting.
4. Measure the voltage of the connectors.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   K52-2 (HT2) - Body ground	10 to 14 V
   K51-13 (HT1) - Body ground	10 to 14 V

Fig 1: Identifying Air Conditioning Amplifier Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

NG: Go to next step 

1. Remove the GLW RLY1 and GLW RLY2 relays from the engine room No. 4 relay block.
2. Measure the resistance of the relays.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   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)

Fig 2: Identifying Relay (GLW RLY1, GLW RLY2) Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE RELAY 

OK: Go to next step 

1. Disconnect the K51 and K52 A/C amplifier connector.
2. Remove the GLW RLY1 and GLW RLY2 relays from the engine room No. 4 relay block.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   K52-2 (HT2) - Relay block GLW RLY2 relay terminal 2	Below 1 Ω
   K51-13 (HT1) - Relay block GLW RLY1 relay terminal 2	Below 1 Ω

Fig 3: Identifying A/C Amplifier And Relays Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

1. Remove the glow plug.
2. Measure the resistance of the glow plug.

   Standard resistance: 

   Below 1 Ω 

Fig 4: Inspecting Water Bypass Glow Plug

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NG: REPLACE WATER BYPASS GLOW PLUG 

OK: Go to next step 

1. Remove the heater blower wire.
2. Measure the resistance of the heater blower wire.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   1 - A	Always	Below 1 Ω
   1 - B	Always	10 kΩ or higher
   2 - B	Always	Below 1 Ω
   2 - A	Always	10 kΩ or higher

Fig 5: Inspecting Heater Blower Wire

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE HEATER BLOWER WIRE 

OK: Go to next step 

1. Disconnect the E78 heater blower wire.
2. Remove the GLW RLY1 and GLW RLY2 relays from the engine room No. 4 relay block.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   Relay block GLW RLY2 relay terminal 5 - E78-2	Below 1 Ω
   Relay block GLW RLY1 relay terminal 5 - E78-1	Below 1 Ω

Fig 6: Identifying Heater Blower Wire And Relays Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE