AIR CONDITIONING SYSTEM > PTC Heater Circuit

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DESCRIPTION

The GLW RLY turns on when it receives a signal from the A/C amplifier. As a result, power is supplied to the heater glow plug.

WIRING DIAGRAM


E109492E01


INSPECTION PROCEDURE

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

  1. Remove the ECU-IG LH fuse from the cowl side junction block LH.

  1. Remove the GLW PLG1 and GLW PLG2 H-fuses from the engine room No. 1 junction block.

  1. 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



NG
REPLACE FUSE
OK


2.CHECK AIR CONDITIONING AMPLIFIER
E107325E09

  1. Remove the A/C amplifier with its connectors still connected.

  1. Turn the engine switch on (IG).

  1. 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.

  1. 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



OK
REPLACE AIR CONDITIONING AMPLIFIER
NG


3.INSPECT RELAY (GLW RLY1, GLW RLY2)
E105451

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

  1. 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)



NG
REPLACE RELAY
OK


4.CHECK WIRE HARNESS (A/C AMPLIFIER - ENGINE ROOM NO. 4 RELAY BLOCK)
E107561E02

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

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

  1. 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



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


5.INSPECT WATER BY-PASS GLOW PLUG
E108196

  1. Remove the glow plug.

  1. Measure the resistance of the glow plug.

    Standard resistance:
    Below 1 Ω



NG
REPLACE WATER BY-PASS GLOW PLUG
OK


6.INSPECT HEATER BLOWER WIRE
E107559E02

  1. Remove the heater blower wire.

  1. 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



NG
REPLACE HEATER BLOWER WIRE
OK


7.CHECK WIRE HARNESS (HEATER BLOWER WIRE - ENGINE ROOM NO. 4 RELAY BLOCK)
E108190E03

  1. Disconnect the E69 heater blower wire.

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

  1. 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



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE