Air Conditioning System Ptc Heater Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT FUSE (LH-IG, GLW PLG1, GLW PLG2)
INSPECT RELAY (GLW RLY1, GLW RLY2)
CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)
INSPECT AIR CONDITIONING AMPLIFIER
INSPECT HEATER BLOWER WIRE
INSPECT WATER BY-PASS GLOW PLUG
AIR CONDITIONING SYSTEM - PTC Heater Circuit |
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
INSPECTION PROCEDURE
| 1.INSPECT FUSE (LH-IG, GLW PLG1, GLW PLG2) |
Remove the LH-IG fuse from the cowl side J/B LH.
Remove the GLW PLG1 and GLW PLG2 fuses from the engine room R/B and J/B No. 1.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Item
| Condition
| Specified Condition
|
LH-IG fuse
| Always
| Below 1 Ω
|
GLW PLG1 fuse
| Always
| Below 1 Ω
|
GLW PLG2 fuse
| Always
| Below 1 Ω
|
| 2.INSPECT RELAY (GLW RLY1, GLW RLY2) |
Remove the GLW RLY1 and GLW RLY2 relays from the engine room R/B and J/B No. 1.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection
| Condition
| Specified Condition
|
3 - 5
| Always
| 10 kΩ or higher
|
3 - 5
| When battery voltage is applied to terminals 1 and 2
| Below 1 Ω
|
| 3.CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY) |
Disconnect the connector from the A/C amplifier.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
Tester Connection (Symbols)
| Condition
| Specified Condition
|
J58-4 (HTR2) - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
J58-23 (HTR1) - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 4.INSPECT AIR CONDITIONING AMPLIFIER |
Reconnect the connector to the A/C amplifier.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
Tester Connection
| Condition
| Specified Condition
|
J58-4 (HTR2) - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
J58-4 (HTR2) - Body ground
| Engine switch on (IG)
While the PTC operating conditions are met (engine is running at 850 rpm or more, ambient temperature is 0°C (32°F) or less, engine coolant temperature is 69°C (156°F) or less, and A/C switch setting is MAX HOT), turn the blower switch to the LO setting.
| Below 1 V
|
J58-23 (HTR1) - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
D47-2 - Body ground
| Engine switch on (IG)
While the PTC operating conditions are met (engine is running at 850 rpm or more, ambient temperature is 0°C (32°F) or less, engine coolant temperature is 69°C (156°F) or less, and A/C switch setting is MAX HOT), turn the blower switch to the LO setting.
| Below 1 V
|
| | REPLACE AIR CONDITIONING AMPLIFIER |
|
|
| 5.INSPECT HEATER BLOWER WIRE |
Remove the grommets and nuts of the water by-pass glow plugs.
Turn the engine switch on (IG).
Perform Active Test by referring to the table below.
Active Test / Air Conditioner:Item
| Test Details / Display (Range)
| Diagnostic Note
|
Electric Heater 1
(Heater 1)
| Electric Heater 1 / OFF, ON
| -
|
Electric Heater 2
(Heater 2)
| Electric Heater 2 / OFF, ON
| -
|
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
Tester connection
| Condition
| Specified condition
|
1 - Body ground
| Perform Active Test / HEATER 1 (Electric Heater 1): ON
| 10 to 14 V
|
2 - Body ground
| Perform Active Test / HEATER 2 (Electric Heater 2): ON
| 10 to 14 V
|
| | REPAIR OR REPLACE HEATER BLOWER WIRE |
|
|
| 6.INSPECT WATER BY-PASS GLOW PLUG |
Remove the water by-pass glow plug.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
- Below 1 Ω
| | REPLACE WATER BY-PASS GLOW PLUG |
|
|
| OK |
|
|
|
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
