AutoCodes – Ford – P0645 Ford

P0645 Ford Code - Air Conditioning Clutch Relay Circuit Malfunction

Quick Answer

The Powertrain Control Module (PCM) monitors the Air Conditioning Clutch Relay (A/CCR) circuit. Common causes include Faulty Air Conditioning Clutch Relay, Air Conditioning Clutch Relay harness is open or shorted, Air Conditioning Clutch Relay circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P0645 Ford indicates Air Conditioning Clutch Relay Circuit Malfunction.
Common causes: Common causes include Faulty Air Conditioning Clutch Relay, Air Conditioning Clutch Relay harness is open or shorted, Air Conditioning Clutch Relay circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 48,891

How popular is this code, among other codes? Medium

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 13, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0645 Ford Description

The Powertrain Control Module (PCM) monitors the Air Conditioning Clutch Relay (A/CCR) circuit. The Diagnostic Trouble Code (DTC) when the PCM grounds the Air Conditioning Clutch Relay circuit, excessive current draw is detected on the Air Conditioning Clutch Relay circuit; or, with the Air Conditioning Clutch Relay circuit not grounded by the PCM, voltage is not detected on the Air Conditioning Clutch Relay circuit (the PCM expects to detect VPWR voltage coming through the Air Conditioning Clutch Relay coil to the Air Conditioning Clutch circuit). The PCM detects an open or short exists in Air Conditioning Clutch Relay control circuit.

OBDII Code P0645 Ford - Air Conditioning Clutch Relay Circuit Malfunction - AutoCodes.com — P0645 Ford Code - Air Conditioning Clutch Relay Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0645 Ford?

Faulty Air Conditioning Clutch Relay
Air Conditioning Clutch Relay harness is open or shorted
Air Conditioning Clutch Relay circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P0645 Ford?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0645 Ford code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Ford Models

P0645 1997 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 1998 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 1999 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 2000 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 2001 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 2002 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 2003 Ford F150 — Wide Open Throttle A/C Cutout Primary Circuit Malfunction
P0645 2006 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2007 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2008 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2009 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2010 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2011 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction
P0645 2012 Ford Fusion — Air Conditioning Clutch Relay Circuit Malfunction

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0645 Ford Code

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dalton
Date: July 14, 2015 at 12:42 am

my son has this problem on his 2005 lincion avator ....po645 ...and eng light is on and codes for misfire on 3and 5 clnyers replaced sparks plugs new ....news coils all of them ...still gets code for misfire and ac /clutch code po645 ....new fuses ...new 30.00 relay for that ..but you cross over relay air comes on ...what I do to fit ....please help..

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