AutoCodes – Ford – P0642 2008 Ford Fusion

P0642 2008 Ford Fusion Code - Sensor Reference Voltage 'A' Circuit Low

Quick Answer

The control module has 2 internal 5-volt reference buses called "5-volt reference 1" and"5-volt reference 2". Common causes include Faulty Engine Control Module (ECM), ECM harness is open or shorted, ECM circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0642 2008 Ford Fusion indicates Sensor Reference Voltage 'A' Circuit Low.
Common causes: Common causes include Faulty Engine Control Module (ECM), ECM harness is open or shorted, ECM circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 3,098

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on May 01, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0642 2008 Ford Fusion Description

The control module has 2 internal 5-volt reference buses called "5-volt reference 1" and"5-volt reference 2". Each reference bus provided 5-volt reference circuit for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to the reference bus. The control module monitors the voltage on the 5-volt reference buses.

OBDII Code P0642 2008 Ford Fusion - Sensor Reference Voltage 'A' Circuit Low - AutoCodes.com — P0642 2008 Ford Fusion Code - Sensor Reference Voltage 'A' Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0642 2008 Ford Fusion?

Faulty Engine Control Module (ECM)
ECM harness is open or shorted
ECM circuit poor electrical connection
Shorted sensor on 5 volt circuit

How to Fix the DTC P0642 2008 Ford Fusion?

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 P0642 2008 Ford Fusion 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.

Need more information about the P0642 2008 Ford Fusion code?

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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 P0642 2008 Ford Fusion Code

1. What does OBDII code P0642 mean for a 2008 Ford Fusion?

The P0642 code indicates a malfunction in the Sensor Reference Voltage 'A' Circuit, specifically that the voltage is lower than normal.

2. What are the common symptoms of a P0642 code on a 2008 Ford Fusion?

Common symptoms include engine stalling, rough idling, poor acceleration, decreased fuel efficiency, and in some cases, the vehicle may not start.

3. What are the possible causes of a P0642 code on a 2008 Ford Fusion?

Potential causes include a faulty Engine Control Module (ECM), damaged wiring or connectors in the sensor circuit, a defective sensor, or a low battery voltage.

4. How can I diagnose a P0642 code on my 2008 Ford Fusion?

Diagnosis typically involves using an OBDII scanner to retrieve the trouble code, inspecting the sensor circuit wiring and connectors for damage, and testing the sensor's voltage output.

5. Can I drive my 2008 Ford Fusion with a P0642 code?

It is not recommended to drive your vehicle with a P0642 code, as it can lead to further damage and potential safety hazards. It's best to address the issue promptly.

6. How can I repair a P0642 code on my 2008 Ford Fusion?

Repair options may include replacing the faulty sensor, repairing damaged wiring or connectors, resetting the ECM, or replacing the ECM if necessary.

7. Are there any DIY tips for fixing a P0642 code on a 2008 Ford Fusion?

If you are experienced with automotive repair, you may attempt to inspect the sensor circuit and connectors for visible damage and replace the sensor yourself if needed. Otherwise, it's best to seek professional help.

8. Will resetting the trouble codes make the P0642 code go away on a 2008 Ford Fusion?

Resetting the trouble codes may temporarily clear the P0642 code, but if the underlying issue is not addressed, the code is likely to reappear once the problem is detected again.

9. How much does it cost to repair a P0642 code on a 2008 Ford Fusion?

The cost of repairing a P0642 code can vary depending on the specific cause of the issue, the parts needed, and labor costs. It's advisable to get a diagnosis from a mechanic for an accurate estimate.

10. Can a P0642 code on a 2008 Ford Fusion cause other problems if left unresolved?

If left unresolved, a P0642 code can lead to further damage to the vehicle's components, decreased performance, and potential safety risks. It's important to address the issue promptly to prevent additional problems.