2020 Volvo XC40 Liftgate Opens Then Closes Immediately – Real Diagnostic Breakdown & Fix

Introduction

One of the more frustrating issues on modern SUVs is when a power liftgate seems to have a mind of its own. It opens like normal… then immediately shuts. No warning, no obvious fault—just unreliable operation.

In this case, I worked through a 2020 Volvo XC40 with exactly that complaint. The liftgate would power open, reach the top (or close to it), and then automatically reverse and shut.

At first glance, you might suspect a module issue, calibration problem, or even a sensor fault. But as with most diagnostics, the root cause turned out to be simpler—and more mechanical—than expected.

Let’s walk through the process step by step.


Vehicle Concern

  • Vehicle: 2020 Volvo XC40

  • System: Power liftgate

  • Complaint:

    • Liftgate opens normally

    • Immediately closes on its own

    • Will not stay in the open position


Initial Inspection & Symptoms

I always start by operating the system myself instead of relying only on the customer’s description.

Here’s what I observed:

  • Liftgate opened under power without hesitation

  • As soon as it reached the top, it reversed and closed

  • No unusual noises from the motors

  • No visible binding or obstruction

At this point, the system looked functional—but clearly wasn’t behaving correctly.


Diagnostic Trouble Codes

Before diving too deep mechanically, I always check for stored faults.

Tools used:

  • Professional scan tool with Volvo capability

I accessed the Tailgate Module (TGM) and checked for codes.

Result:

  • No active or stored fault codes

That’s important. When there are no codes, it usually means:

  • The module thinks it’s operating normally

  • The issue is either mechanical or a condition the system interprets incorrectly


Diagnostic Process

Step 1: Verify Liftgate Calibration

These vehicles use a learned height position, so I wanted to rule out a memory issue.

Procedure:

  1. Open liftgate

  2. Manually set desired height

  3. Press and hold close button for ~5 seconds

Result:

  • Liftgate still closed immediately after releasing it

Why this matters:
If calibration was the issue, this would have fixed it. Since it didn’t, I moved on.


Step 2: Assist the Liftgate Manually

Next, I manually pushed the liftgate fully open and held it in position.

Observation:

  • While I held it, it stayed open

  • As soon as I let go, it began to close

This is a huge clue.


Step 3: Check Mechanical Support

Now I wanted to see how the liftgate behaved without power influence.

I carefully pushed the liftgate downward by hand.

What I felt:

  • It moved freely

  • No resistance

  • Felt like a non-powered trunk lid

That’s not normal.

On a properly functioning power liftgate:

  • You should feel resistance from the struts

  • It should not drop easily

  • The system should feel “assisted,” even manually


Step 4: Evaluate Strut Performance

The XC40 uses motorized liftgate struts with internal gas assist.

That gas pressure plays a critical role:

  • It supports the weight of the liftgate

  • Reduces load on the electric motors

  • Helps stabilize the gate at the top

Even though I didn’t see any oil leaks, that doesn’t mean the struts are good.

Most failures are internal gas pressure loss—not external leakage.


Key Findings

After testing, the evidence pointed clearly to one issue:

  • Liftgate could not support its own weight

  • Struts provided little to no resistance

  • System closed automatically once support was removed

This triggered the vehicle’s anti-pinch / safety logic, causing it to shut the liftgate.


Final Diagnosis / Recommendation

Failed liftgate power struts (gas assist worn out).

Recommended Repair:

  • Replace both liftgate struts as a pair

Why both?

  • They wear at the same rate

  • The control module expects balanced operation

  • Replacing one can cause uneven movement or faults

After Replacement:

  • Reinitialize liftgate height memory

  • Cycle liftgate open/close to confirm proper operation


Common Causes of This Issue

This type of failure isn’t unique to Volvo. Many modern SUVs with power liftgates experience similar problems.

Common causes include:

1. Worn Gas Struts

  • Loss of internal pressure over time

  • Most common cause

2. High Usage

  • Frequent open/close cycles accelerate wear

3. Climate Effects

  • Extreme heat or cold affects internal seals

4. Heavy Liftgate Design

  • Panoramic glass and power components add weight

5. Age

  • Even without leaks, struts weaken gradually


Tips for DIYers or Buyers

If you’re diagnosing or inspecting a vehicle with a power liftgate, here are a few practical tips:

1. Perform the “Manual Drop Test”

  • Open the liftgate

  • Gently push it down

If it drops easily → struts are weak.


2. Don’t Rely on Visible Leaks

  • Most failed struts look perfectly clean

  • Internal failure is far more common


3. Listen to the System Behavior

  • Immediate closing = system thinks something is wrong

  • Often mechanical, not electronic


4. Replace in Pairs

  • Saves time and prevents repeat repairs


5. Support the Liftgate During Repair

Safety note:
Once a strut is removed, the liftgate can drop suddenly.

Always:

  • Use a prop rod or helper

  • Never trust the remaining strut


6. Use Quality Parts

Cheap aftermarket struts can:

  • Cause synchronization issues

  • Trigger module faults

  • Fail prematurely

Stick with:

  • OEM or high-quality manufacturers


When to Refer to a Professional

If you see any of the following, it’s worth involving a professional:

  • Uneven liftgate movement (twisting)

  • Electrical faults or module codes

  • Wiring damage near hinges

  • No response from liftgate at all

Those point toward electrical or control issues rather than mechanical failure.


Conclusion

This was a perfect example of why diagnostics should always start with basic mechanical checks before chasing electronics.

Even though the liftgate system is controlled by modules and sensors, the root cause was simple:

The liftgate struts could no longer support the weight of the door.

Once that happens, the system interprets it as a fault and shuts the liftgate for safety.

By stepping through the process logically—checking calibration, observing behavior, and testing manually—we avoided unnecessary parts and quickly identified the real issue.


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