AutoCodes – Mercury – B2420 Mercury

B2420 Mercury Code - Power Liftgate/Trunk Sensor 2 Invalid

Quick Answer

When the power liftgate moves in the close direction, the Liftgate/Trunk Module (LTM) monitors the pinch strips and motor position sensor for obstacle detection. Common causes include Liftgate alignment, Faulty Power Liftgate/Trunk Sensor 2, Power Liftgate/Trunk Sensor 2 harness is open or shorted. 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: B2420 Mercury indicates Power Liftgate/Trunk Sensor 2 Invalid.
Common causes: Common causes include Liftgate alignment, Faulty Power Liftgate/Trunk Sensor 2, Power Liftgate/Trunk Sensor 2 harness is open or shorted.
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 787

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Dec 08, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2420 Mercury Description

When the power liftgate moves in the close direction, the Liftgate/Trunk Module (LTM) monitors the pinch strips and motor position sensor for obstacle detection. If the LTM detects an obstacle, it reverses the power liftgate. The LTM monitors the left and right pinch strips and if either pinch strip is pressed the LTM reverses the power liftgate. The LTM monitors the position sensor feedback for position and movement. If the LTM is unable to determine the liftgate position or the movement indicates an obstacle the LTM reverses the power liftgate. The LTM also monitors the power liftgate latch status once the liftgate closes to a secondary latch position. If the liftgate is unable to obtain a primary latch position the LTM aborts the power close.

OBDII Code B2420 Mercury - Power Liftgate/Trunk Sensor 2 Invalid - AutoCodes.com — B2420 Mercury Code - Power Liftgate/Trunk Sensor 2 Invalid

What does this mean?

What are the Possible Causes of the DTC B2420 Mercury?

Liftgate alignment
Faulty Power Liftgate/Trunk Sensor 2
Power Liftgate/Trunk Sensor 2 harness is open or shorted
Power Liftgate/Trunk Sensor 2 circuit poor electrical connection
Faulty Power liftgate latch
Faulty Power liftgate motor
Faulty Liftgate/Trunk Module (LTM)

How to Fix the DTC B2420 Mercury?

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 B2420 Mercury 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 B2420 Mercury code?

Need more information on how to fix the B2420 Mercury code? Get Access to Factory Service Manuals

Need Help with the 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 B2420 Mercury Code

1. What does the OBDII code B2420 mean on a Mercury vehicle?

B2420 indicates an issue with the Power Liftgate/Trunk Sensor 2, where the sensor is providing invalid or inconsistent data to the vehicle's control module.

2. What are the symptoms of the B2420 code in a Mercury?

Symptoms may include the power liftgate or trunk failing to open, close, or latch properly, unusual noises during operation, or a warning light on the dashboard.

3. What causes the B2420 code to appear?

Common causes include a faulty liftgate/trunk sensor, damaged wiring or connectors, misaligned liftgate components, or a malfunctioning liftgate control module.

4. Can I still manually open my trunk or liftgate with a B2420 code?

In most cases, the trunk or liftgate can still be operated manually, but automatic functionality may be disabled or unreliable.

5. How do I diagnose the B2420 code on my Mercury?

Diagnosis involves inspecting the liftgate sensor for damage, checking wiring and connectors for continuity, and using a scan tool to confirm the sensor's signal output.

6. Can a damaged liftgate sensor cause the B2420 code?

Yes, a damaged or defective liftgate/trunk sensor is a common cause of this code, as it fails to send accurate data to the vehicle's control module.

7. Is the B2420 code specific to Mercury vehicles?

While the code is common in Mercury vehicles, it may also apply to other Ford-related brands with similar power liftgate systems.

8. Can I clear the B2420 code without fixing the issue?

Clearing the code without repairs may temporarily remove the warning, but the issue will likely return if the underlying problem isn't resolved.

9. How much does it cost to fix the B2420 code on a Mercury?

Repair costs vary depending on the issue, with sensor replacement typically costing $100â€“$300, while wiring repairs or module replacements may cost more.

10. Can the B2420 code damage other components in my car?

While the code itself typically doesn't cause further damage, ignoring the issue could strain the liftgate motor or lead to additional electrical problems over time.