Air Conditioning System Ptc Heater Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (ECU-IG LH, GLW PLG1, GLW PLG2)

CHECK AIR CONDITIONING AMPLIFIER

INSPECT RELAY (GLW RLY1, GLW RLY2)

CHECK WIRE HARNESS (A/C AMPLIFIER - ENGINE ROOM NO. 4 RELAY BLOCK)

INSPECT WATER BY-PASS GLOW PLUG

INSPECT HEATER BLOWER WIRE

CHECK WIRE HARNESS (HEATER BLOWER WIRE - ENGINE ROOM NO. 4 RELAY BLOCK)

DESCRIPTION

WIRING DIAGRAM

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-fuses from the engine room No. 1 junction block.
   

3. Measure the resistance of the fuses.
   

Standard resistance:

Tester Item	Condition	Specified Condition
ECU-IG LH fuse	Always	Below 1 Ω
GLW PLG1 H-fuse	Always	Below 1 Ω
GLW PLG2 H-fuse	Always	Below 1 Ω

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
   L52-2 (HT2) - Body ground	10 to 14 V
   L52-1 (HT1) - Body ground	10 to 14 V

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

1. Disconnect the L51 and L52 A/C amplifier connectors.
   

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
   L51-13 (HT1) - Relay block GLW RLY1 relay terminal 2	Below 1 Ω
   L52-2 (HT2) - Relay block GLW RLY2 relay terminal 2	Below 1 Ω

1. Remove the glow plug.
   

2. Measure the resistance of the glow plug.
   

   Standard resistance:

   Below 1 Ω
   

1. Remove the heater blower wire.
   

2. Measure the resistance of the blower wire.
   

   Standard resistance:

   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

1. Disconnect the E69 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
   Relay block GLW RLY1 relay terminal 5 - E69-1	Below 1 Ω
   Relay block GLW RLY2 relay terminal 5 - E69-2	Below 1 Ω