Land Cruiser URJ200 URJ202 GRJ200 VDJ200 - HEATING / AIR CONDITIONING
AIR CONDITIONING SYSTEM (for Manual Air Conditioning System) - TERMINALS OF ECU
| CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY |
Disconnect the E81 air conditioning amplifier assembly connector.
Measure the voltage and resistance according to the value(s) in the table below.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
| E81-21 (+B1) - E81-14 (GND) | R - W-B | Battery power source | Always | 11 to 14 V |
| E81-1 (IG+) - E81-14 (GND) | G - W-B | Ignition power supply | Ignition switch ON | 11 to 14 V |
| Ignition switch off | Below 1 V | |||
| E81-14 (GND) - Body ground | W-B - Body ground | Ground | Always | Below 1 Ω |
If the result is not as specified, there may be a malfunction on the wire harness side.
Reconnect the E81 air conditioning amplifier assembly connector.
Measure the voltage, resistance and waveform according to the value(s) in the table below.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
| E81-8 (LOCK) - E81-35 (SG-5) | L - G | Compressor lock sensor signal | Engine idling Blower switch LO level A/C switch on (magnet clutch on) | Pulse generation (see waveform 1) |
| E81-35 (SG-5) - Body ground | G - Body ground | Ground for compressor lock sensor signal | Always | Below 1 Ω |
| E81-13 (SG-2) - Body ground | G - Body ground | Ground for pressure sensor | Always | Below 1 Ω |
| E81-17 (AC1) - Body ground | L - Body ground | Air conditioning operation request signal | Engine idling Blower switch LO level A/C switch off | 11 to 14 V |
| Engine idling Blower switch LO level A/C switch on | Below 1 V | |||
| E81-27 (ACT) - Body ground | G - Body ground | Magnet clutch operation permission signal | Engine idling Blower switch LO level A/C switch off or A/C switch on (magnet clutch off) | 11 to 14 V |
| Engine idling Blower switch LO level A/C switch on (magnet clutch on) | Below 1 V | |||
| E81-5 (TAM) - E81-13 (SG-2) | V - G | Ambient temperature sensor signal | Ignition switch ON Ambient temperature 25°C (77°F) | 1.6 to 1.8 V |
| Ignition switch ON Ambient temperature 50°C (122°F) | 0.5 to 0.7 V | |||
| E81-30 (S5-1) - E81-13 (SG-2) | LG - G | Power supply for pressure sensor | Ignition switch ON | 4.5 to 5.5 V |
| E81-9 (PRE) - E81-13 (SG-2) | R - G | Air conditioning pressure sensor signal | Engine idling Blower switch LO level A/C switch on | 0.63 to 4.72 V |
| Engine idling Blower switch LO level A/C switch off | 0.63 to 4.72 V | |||
| E81-20 (MGC) - E81-14 (GND) | R - W-B | Magnet clutch operation signal | Engine idling Blower switch LO level A/C switch on (magnet clutch on permitted) | Below 1 V |
| Engine idling Blower switch LO level A/C switch off or on (magnet clutch on not permitted) | 11 to 14 V | |||
| E81-23 (BLW) - E81-14 (GND) | R - W-B | Blower motor control signal | Ignition switch ON Blower switch LO level | Pulse generation (see waveform 2) |
| E81-37 (LIN1) - E81-14 (GND) | Y - W-B | LIN communication signal | Ignition switch ON | Pulse generation |
| E81-25 (ALT) - Body ground | R - Body ground | Generator signal | Engine idling | Pulse generation |
| E81-3 (PTC1) - Body ground* | W - Body ground | PTC heater relay operation signal | Engine idling Set temperature MAX. HOT Engine coolant temperature below 65°C (149°F) Ambient temperature below 10°C (50°F) Blower switch off → LO level | Below 1 V → 11 to 14 V |
| E81-22 (PTC2) - Body ground* | R - Body ground | |||
| E81-4 (PTC3) - Body ground* | R - Body ground | |||
| z54-4 (B BUS) - z54-2 (BUS G) | - | Power supply for BUS IC | Ignition switch ON | 11 to 14 V |
| z54-5 (SGA) - Body ground | - | Ground for No. 1 cooler thermistor | Always | Below 1 Ω |
| z54-2 (BUS G) - Body ground | - | Ground for BUS IC | Always | Below 1 Ω |
| z54-6 (TEA) - z54-5 (SGA) | - | No. 1 cooler thermistor signal | Ignition switch ON Evaporator temperature 15°C (59°F) | 1.4 to 1.8 V |
| z54-3 (BUS) - z54-2 (BUS G) | - | BUS IC control signal | Ignition switch ON | Pulse generation |
*: w/ PTC Heater
If the result is not as specified, the air conditioning amplifier assembly may have a malfunction.
Using an oscilloscope, check waveform 1.
| Item | Content |
| Terminal No. (Symbol) | E81-8 (LOCK) - E81-35 (SG-5) |
| Tool Setting | 200 mV/DIV., 10 ms/DIV. |
| Condition | Engine idling Blower switch LO level A/C switch on (magnet clutch on) |
- HINT:
- When the rear blower level is increased, the duty ratio changes accordingly.
Using an oscilloscope, check waveform 2.
| Item | Content |
| Terminal No. (Symbol) | E81-23 (BLW) - E81-14 (GND) |
| Tool Setting | 1 V/DIV., 500 μs/DIV. |
| Condition | Ignition switch ON Blower switch LO level |
- HINT:
- When the blower level is increased, the duty ratio changes accordingly.
| CHECK AIR CONDITIONING CONTROL ASSEMBLY |
Disconnect the F10 air conditioning control assembly connector.
Measure the resistance and voltage according to the value(s) in the table below.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
| F10-7 (IG+) - F10-1 (GND) | G - W-B | Ignition power supply | Ignition switch ON | 11 to 14 V |
| Ignition switch off | Below 1 V | |||
| F10-1 (GND) - Body ground | W-B - Body ground | Ground | Always | Below 1 Ω |
If the result is not as specified, there may be a malfunction on the wire harness side.