1A
A/C System Circuits Check
Wiring Diagram
1. Blower fan motor 6. A/C compressor 11. Evaporator temp. sensor 16. “IGN2” fuse
2. Blower fan switch 7. A/C condenser fan control relay 12. “IG2 SIG” fuse 17. “HTR” fuse
3. A/C switch 8. A/C Condenser fan motor 13. Relay box 18. “IG” fuse
4. A/C refrigerant pressure switch 9. ECM 14. “A/C” fuse 19. 4WD controller
5. Compressor relay 10. Ignition switch 15. “IGN1” fuse *: Right-hand steering vehicle
Troubleshooting
WARNING:
Keep hands, tools, and clothing away from A/C condenser fan to help prevent personal injury. This fan is electric and can come on whether or not the engine is running. The fan can start automatically in response to the ECT sensor with the ignition switch in the “ON” position.
Step Action YES NO
1
A/C evaporator temp. sensor check
1) Disconnect connectors from ECM with ignition switch turned OFF.
2) Check for proper connection to “E118-15” and “E118-35” terminals of ECM connector.
3) If OK, measure resistance between “E118-15” and “E118-35” terminals of ECM connector.
Evaporator temp. sensor resistance
At 0 °C: 6.3 – 6.9 kΩ
At 25 °C: 1.8 – 2.2 kΩ
Is it within specification?
Go to Step 2.
Faulty A/C evaporator temp. sensor or its circuit.
2
A/C refrigerant pressure switch signal check
1) Connect connectors to ECM with ignition switch turned OFF.
2) Measure voltage between “E118-30” terminal of ECM connector and vehicle body ground under each condition given below.
A/C refrigerant pressure switch signal
Ignition switch ON, blower fan switch and A/C switch ON: 0 – 1 V
Ignition switch ON and A/C switch OFF: 10 – 14 V
Is each voltage within specified value?
Go to Step 3.
“GRN/WHT” or “GRN/ BLK” wire in open circuit in shorted to other circuit.
If wires are OK, faulty A/C refrigerant pressure switch, improper refrigerant amount or 4WD controller.
3
A/C condenser fan control system check
Is A/C condenser fan started when A/C and blower fan switch turned ON while engine running?
Go to Step 4.
Go to Step 5.
4
A/C condenser fan control system check
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Start engine and select “Data List” mode on scan tool.
3) Warm up engine until engine coolant temperature is 110 °C, 230 °F or higher and A/C switch OFF. (If engine coolant temperature does not rise, check engine cooling system or ECT sensor.)
Is A/C condenser fan started when engine coolant temperature reached above temperature?
Go to Step 13.
Go to Step 5.
5
Is there DTC(s) ECT sensor circuit (DTC P0116/ P0117/P0118) and/or A/C condenser fan circuit (DTC P0481)?
Go to corresponding DTC flow.
Go to Step 6.
6
A/C fuse check
1) Turn OFF ignition switch.
2) Check for fuse blown at “A/C” fuse in relay box.
Is “A/C” fuse in good condition?
Go to Step 7.
Replace “A/C” fuse and check for short.
7
A/C condenser fan control relay circuit check
1) Remove A/C condenser fan control relay.
2) Check for proper connection to A/C condenser fan control relay at “RED” and “RED/ BLU” wire terminals.
3) If OK, measure voltage between “RED” wire terminal of A/C condenser fan control relay connector and vehicle body ground.
Is voltage 10 – 14 V?
Go to Step 8.
“RED” wire in open or high resistance circuit.
8
A/C condenser fan control relay circuit check
1) Disconnect connector from A/C condenser fan motor with ignition switch turned OFF.
2) Check for proper connection to A/C condenser fan motor at “RED/BLU” and “BLK” wire terminals.
3) Measure resistance between “RED/BLU” wire terminal of A/C condenser fan motor and vehicle body ground.
Is resistance infinity?
Go to Step 9.
“RED/BLU” wire shorted to ground circuit.
9
A/C condenser fan control relay circuit check
1) Measure voltage between “RED/BLU” wire terminal of A/C condenser fan motor and vehicle body ground with ignition switch turned ON.
Is voltage 0 V?
Go to Step 10.
“RED/BLU” wire shorted to power supply circuit.
10
A/C condenser fan control relay circuit check
1) Connect A/C condenser fan control relay to relay box with ignition switch turned OFF.
2) Measure voltage between “RED/BLU” wire terminal of A/C condenser fan motor and vehicle body ground with ignition switch turned ON.
Is voltage 10 – 14 V?
Go to Step 12.
Go to Step 11.
11
A/C condenser fan control relay check
1) Check A/C condenser fan control relay referring to Main Relay, Fuel Pump Relay, A/C Compressor Relay and A/C Condenser Fan Control Relay Inspection:M13A .
Is check result satisfactory?
“RED/BLU” wire in open or high resistance circuit.
Replace A/C condenser fan control relay.
12
A/C condenser fan motor check
1) Check A/C condenser fan motor referring to Condenser Cooling Fan Assembly On-Vehicle Inspection (M13A Model) .
Is check result satisfactory?
“BLK” wire in open or high resistance circuit.
Replace A/C condenser fan motor.
13
A/C compressor control system check
Is A/C compressor started when A/C and blower fan switch turned ON while engine running?
A/C system is in good condition.
Go to Step 14.
14
A/C compressor relay circuit check
1) Measure voltage between “E117-11” terminal of ECM connector and vehicle body ground under the following condition.
Voltage between “E117-11” terminal of ECM connector and ground
While engine running and A/C switch OFF: 10 – 14 V
While engine running, A/C and blower fan selector switch ON: 0 – 1 V
Are check result satisfactory?
Go to Step 15.
Go to Step 16.
15
A/C compressor relay check
1) Check A/C compressor relay referring to Main Relay, Fuel Pump Relay, A/C Compressor Relay and A/C Condenser Fan Control Relay Inspection:M13A .
Is it in good condition?
A/C compressor drive circuit malfunction.
Replace A/C compressor relay.
16
A/C compressor relay circuit check
1) Remove A/C compressor relay with ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between “LT GRN” wire terminal of A/C compressor relay connector and vehicle body ground.
Is voltage 10 – 14 V?
Go to Step 17.
“LT GRN” and/or “RED/ BLU” wire in open circuit.
17
A/C compressor relay check
1) Check A/C compressor relay referring to Main Relay, Fuel Pump Relay, A/C Compressor Relay and A/C Condenser Fan Control Relay Inspection:M13A .
Is it in good condition?
“PNK/BLU” and/or “PNK” wire circuit open. If OK, substitute a known-good ECM and recheck.
Replace A/C compressor relay.
NOTE:
When A/C evaporator temp. is below 3.5 °C (38.3 °F), A/C remains OFF (“E117-11” terminal voltage becomes 10 – 14 V). This condition is not abnormal.