DTC P0645 / P0646 / P0647
Precautions: General safety (00)
DTC Detecting Condition and Trouble Area
| DTC detecting condition | Trouble area |
|---|---|
|
P0645: A/C Clutch Relay Control Circuit A/C compressor relay drive circuit is open. (3 D/C detection logic but MIL does not light up) |
•A/C compressor relay and/or its circuit
•ECM |
|
P0646: A/C Clutch Relay Control Circuit Low A/C compressor relay drive circuit is shorted to ground. (3 D/C detection logic but MIL does not light up) |
|
|
P0647: A/C Clutch Relay Control Circuit High A/C compressor relay drive circuit is shorted to power supply. (3 D/C detection logic but MIL does not light up) |
Circuit Diagram
| [A]: | ECM connector (View: [a]) | 1. | A/C compressor relay | 4. | To main fuse box |
| A1: | A/C compressor relay power supply circuit (coil side) | 2. | A/C compressor | 5. | ECM |
| B1: | A/C compressor relay drive circuit | 3. | To main relay | 6. | “CPRSR” fuse |
DTC Confirmation Procedure
NOTE:
•Check that the following conditions are met in this “DTC Confirmation Procedure”.
—Battery voltage > 8.5 V
—Evaporator temperature > 3 °C (37 °F)
•Check that the following DTCs are not detected in this “DTC Confirmation Procedure”.—Evaporator temperature > 3 °C (37 °F)
—ECT sensor (P0116, P0117 and P0118)
—A/C refrigerant pressure sensor (P0530)
—A/C refrigerant pressure sensor (P0530)
1)Run engine at idle speed for 10 sec.
2)Set A/C switch ON for 10 sec.
3)Set A/C switch OFF.
DTC Troubleshooting
| Step | Action | Yes | No |
|---|---|---|---|
| 1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
|
|
| 2 |
A/C compressor relay power supply circuit (coil side) check
1)With ignition “OFF”, remove A/C compressor relay.
2)Check for proper terminal connection to A/C compressor relay connector.
3)If connection is OK, set ignition “ON”.
4)Check that voltage between “A1” and ground is battery voltage.
Is check result OK?
|
Go to Step 3.
|
Repair or replace defective wire harness.
|
| 3 |
A/C compressor relay check
1)Check A/C compressor relay.
•Manual A/C model:
 •Auto A/C model: Is check result OK?
|
Go to Step 4.
|
Replace A/C compressor relay.
|
| 4 |
A/C compressor relay drive circuit check
1)With ignition “OFF”, disconnect “C01” and “E01” connectors from ECM.
2)Check for proper terminal connection to “C01” and “E01” connectors.
3)If connections are OK, check the following points.
•Resistance of “B1” circuit: less than 1 Ω
•Resistance between “B1” circuit and ground: infinity •Resistance between “B1” circuit terminal and other terminal at A/C compressor relay connector: infinity •Voltage of “B1” circuit: approx. 0 V (When ignition is “ON”) Is check result OK?
|
Replace ECM and recheck DTC.
|
Repair or replace defective wire harness.
|