DESCRIPTION
When the heater switch assembly is pushed, the air conditioning amplifier assembly turns on the viscous heater relay and operates the viscous heater. If the viscous heater does not operate when the heater switch assembly is pushed, there may be a problem in the circuit shown below.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
When the servo motor or air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.
Tech Tips
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
READ VALUE USING GTS (IDLE UP/PWR HEAT SWITCH)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Body Electrical / Air Conditioner / Data List.
Check the value(s) by referring to the table below.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| IDLE UP/PWR HEAT Switch | Heater switch assembly | ON or OFF | ON: Heater switch assembly on OFF: Heater switch assembly off |
- |
| Tester Display |
|---|
| IDLE UP/PWR HEAT Switch |
| OK |
|---|
| The display is as specified in the normal condition column. |
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - BATTERY AND BODY GROUND) Click here |
| OK |
|
PERFORM ACTIVE TEST USING GTS
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Body Electrical / Air Conditioner / Active Test.
Check the operation by referring to the table below.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Viscous Heater | Viscous heater relay | ON/OFF | - |
| Tester Display |
|---|
| Viscous Heater |
| OK |
|---|
| Viscous heater relay operates. |
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here |
| NG |
|
INSPECT VISCOUS HEATER RELAY (VISCOUS) Click here |
CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - BATTERY AND BODY GROUND)
| *a | Front view of wire harness connector (to Heater Switch Assembly) |
Disconnect the heater switch assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT HEATER SWITCH ASSEMBLY
Remove the heater switch assembly.
Inspect the heater switch assembly.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE HEATER SWITCH ASSEMBLY Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)
Disconnect the G76 heater switch assembly connector
Disconnect the G33 air conditioning amplifier assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT VISCOUS HEATER RELAY (VISCOUS)
Remove the viscous heater relay (VISCOUS) from the No. 5 instrument panel relay block.
Inspect the viscous heater relay (VISCOUS).
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE VISCOUS HEATER RELAY |
| OK |
|
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY)
Disconnect the air conditioning amplifier assembly connector.
| *a | Rear view of wire harness connector (to Air Conditioning Amplifier Assembly) |
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY
Remove the compressor assembly with magnet clutch.
Inspect the compressor assembly with magnet clutch.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (VISCOUS RELAY - VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY AND BATTERY)
Remove the viscous heater relay (VISCOUS) from the No. 5 instrument panel relay block.
Disconnect the C107 viscous with magnet clutch heater assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |