Pinpoint Test B : DTC P0645: Notes
WARNING: This page is about a different car, the 2015 Lincoln MKT. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic Overview
Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Service Information for information about these practices.
Refer to Automatic Climate Control System , for schematic and connector information.
Normal Operation and Fault Conditions
Voltage is provided to the A/C clutch relay coil. When A/C is requested and A/C line pressures allow, a ground is provided to the A/C clutch relay coil from the PCM, energizing the A/C clutch relay.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P0645 | A/C Clutch Relay Control Circuit: No Sub Type Information | The DTC sets when the PCM grounds the relay circuit and more current than expected is detected on the relay circuit. The DTC also sets when the relay circuit is off and no voltage is detected on the relay circuit. |
Possible Sources
- Wiring, terminals or connectors
- A/C clutch relay
- PCM
Visual Inspection and Diagnostic Pre-checks
- Inspect loose or corroded PCM and A/C clutch relay connections.