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Written by: Administrator

Category: PLC Battery

Published: 21 September 2026

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There is a particular kind of warning that can make a Volvo owner uneasy.

The engine starts normally. The 12V battery appears healthy. The vehicle drives without any obvious problems. Yet the dashboard suddenly displays:

“Volvo On Call Service Required.”

For an older Volvo equipped with a Vehicle Connectivity Module, or VCM, the problem may be hiding in a place most owners never think about: a small backup battery inside the communication module.

This is where the Volvo 31350776 Battery becomes interesting.

Rather than replacing an entire VCM immediately, owners may be able to address a battery-related fault by replacing the dedicated backup battery—provided the vehicle diagnosis and part-number verification confirm that this is the correct repair.

In this review, we take a closer look at the TLM-1550 replacement battery, its relationship with Volvo 31350776 and XCS67890L, the symptoms of a worn VCM battery, and the practical issues that should be considered before installation.

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The Problem Usually Starts With a Small Warning

The first clue is often not a dramatic electrical failure.

Instead, the vehicle may continue operating normally while a message related to Volvo On Call appears on the dashboard.

That can lead owners down the wrong troubleshooting path.

They may replace the vehicle's main battery.

They may inspect fuses.

They may restart the infotainment system.

They may even assume the entire telematics system has failed.

But the VCM has its own backup power source.

When that battery reaches the end of its useful life, the VCM can report a battery-related fault even though the main vehicle battery is perfectly capable of starting the car.

For vehicles using the applicable configuration, the VCM Backup Battery is therefore a component worth investigating before considering replacement of the entire module.

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What Exactly Is Being Replaced?

The battery discussed here is not the large 12V battery under the hood.

It is a small rechargeable battery located inside the VCM.

The VCM is part of the vehicle's connectivity architecture and can be associated with communication functions such as Volvo On Call and SOS-related services, depending on the vehicle generation and market.

The backup battery provides reserve power for the module.

In the relevant application, the original battery may be identified by:

Volvo 31350776

Other identifiers can also appear during the search process, including:

XCS67890L

and

TLM-1550

This is why searching for the TLM-1550 can be more useful than searching only for the generic phrase “Volvo battery.”

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First Impression: A Specialized Replacement, Not a Generic Cell

One thing becomes clear when looking at this type of replacement battery: it should not be treated like a conventional consumer rechargeable cell.

The application requires more than simply matching the voltage.

A suitable replacement needs to be compatible with the VCM's:

• Electrical requirements

• Battery chemistry

• Voltage

• Capacity

• Connector

• Polarity

• Physical dimensions

• Protection arrangement

• Installation method

Some replacement listings associate this application with a battery in the approximately 4V / 600mAh range.

However, the actual battery installed in a vehicle should always be checked before ordering.

This is particularly important because Volvo used different VCM configurations over different model years.

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Why the 31350776 Number Matters

The biggest mistake an owner can make is assuming that every Volvo VCM uses the same battery.

It does not.

The number 31350776 is useful because it gives the search a much more specific target.

If the original battery or vehicle documentation identifies the required component as 31350776, a Volvo 31350776 Battery becomes a much more relevant replacement candidate.

By contrast, buying a product simply advertised as a “Volvo VCM battery” leaves too much uncertainty.

Another Volvo VCM generation may use a different part number, including 31450445 in some applications.

So the correct procedure is not:

Volvo → VCM → buy any battery.

It is:

VIN → VCM identification → original battery → compatible replacement.

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What About XCS67890L?

The identifier XCS67890L is another term owners may encounter while researching this replacement.

It can be useful as a cross-reference when searching for the same general VCM backup-battery application.

That makes the XCS67890L search term particularly useful for owners who find this number printed on their existing battery or in replacement-battery listings.

However, cross-reference numbers should still be verified rather than blindly assumed to be interchangeable.

The safest approach is to compare the complete battery assembly, not just one number.

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The Most Important Diagnostic Code: U105000

One of the most relevant VCM faults in this context is:

VCM-U105000 — Back-up Battery Life Exceedance

The wording is significant.

It points specifically toward the service life of the VCM backup battery.

That does not mean every U105000 case should be handled by simply installing a new battery and stopping there.

Volvo service information has included specific procedures for this type of VCM backup-battery condition, including software-related steps.

Therefore, if a diagnostic scan shows U105000, the proper response is to follow the applicable service procedure.

The VCM Backup Battery can solve the hardware side of the problem when the battery is confirmed to be the cause, but diagnostic and software procedures may still be required afterward.

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Other VCM Battery-Related Faults

Older Volvo service information may also reference codes such as:

• U210909

• U210996

The exact fault-code behavior depends on the vehicle platform and software version.

This is another reason not to diagnose the problem purely from the dashboard warning.

A warning tells you that the vehicle has detected a problem.

A diagnostic scan tells you where to investigate.

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How the Replacement Process Looks in the Real World

Replacing a VCM battery is not particularly complicated for an experienced automotive electronics technician, but it is more delicate than changing a normal vehicle battery.

The challenge is access.

The VCM is not necessarily sitting in an obvious location beneath the hood.

Depending on the Volvo platform, it may be located behind luggage-compartment trim or near the rear cargo area.

That means the job can involve:

Interior trim removal → VCM access → module removal → battery replacement → module reinstallation → diagnostic procedure

The actual location varies between vehicle generations.

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Step 1: Let the Vehicle Go to Sleep

Before touching the VCM, the vehicle should be shut down properly.

A sensible preparation sequence is:

1. Park the vehicle safely.

2. Switch off the ignition.

3. Turn off unnecessary electrical equipment.

4. Keep the key or remote away from the vehicle.

5. Allow the vehicle to enter its sleep state.

6. Follow the vehicle-specific power-disconnection procedure where required.

This matters because the VCM is an electronic control module rather than a standalone consumer device.

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Step 2: Find the VCM

This is where online repair videos can become misleading.

A video showing the VCM on one Volvo model does not necessarily apply to another.

Even vehicles with similar body styles can have different electronic-module locations.

On some applications, the VCM is located in the rear of the vehicle behind trim panels.

Once the correct location has been identified, remove only the panels necessary to gain access.

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Step 3: Remove the Trim Without Damaging It

Plastic clips and interior panels are easy to damage if the wrong tool is used.

A plastic trim-removal tool is preferable to a metal screwdriver.

Work methodically:

fasteners → clips → trim panel

Do not pull the panel aggressively.

There may be wiring harnesses or other electrical components behind the trim.

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Step 4: Verify the VCM Before Opening It

This is one of the best opportunities to prevent an incorrect repair.

Before opening the module, record:

• VCM part number

• Vehicle VIN

• Original battery part number

• Connector type

• Battery dimensions

• Battery label

If the original component corresponds to 31350776, the Volvo 31350776 Battery is relevant for further compatibility checking.

If the VCM uses another battery configuration, stop and identify that version instead.

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Step 5: Disconnect the VCM Carefully

The VCM connectors should never be treated like ordinary plugs.

Many automotive connectors use locking mechanisms.

Release the lock before pulling the connector.

Avoid pulling on wires.

This is especially important because damage to a VCM connector or PCB can be significantly more expensive than the battery itself.

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Step 6: Access the Backup Battery

Once the VCM has been opened according to the appropriate repair procedure, the backup battery should be identifiable as a dedicated battery assembly.

It may consist of a small battery pack with:

• Connecting wires

• Dedicated plug

• Protective circuitry

• Mounting material

This is why cutting the wires and installing a random rechargeable cell is not a recommended repair method.

The replacement needs to be electrically and mechanically appropriate.

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Step 7: Remove the Old Battery

This is arguably the most delicate part of the physical repair.

First locate the battery connector.

Then:

1. Secure the PCB.

2. Release the connector lock.

3. Remove the connector carefully.

4. Remove the battery from its mounting position.

5. Avoid stressing the wires or PCB.

Do not pull the connector by the cable.

A small connector can be surprisingly easy to damage.

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Step 8: Install the New Battery

Before installation, compare the replacement with the old battery.

Check:

Voltage

Capacity

Polarity

Connector

Dimensions

Mounting arrangement

The TLM-1550 replacement should only be installed when these characteristics are appropriate for the VCM being serviced.

Once confirmed, position the battery so that it does not interfere with the circuit board or enclosure.

Route the wires carefully.

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Step 9: Reassemble the Module

After connecting the new battery, make sure the connector is completely seated.

Then inspect the battery wires.

They should not be:

• Pinched

• Exposed unnecessarily

• Pressed against sharp edges

• Trapped under the PCB

• Under excessive tension

Close the VCM and reinstall it in the vehicle.

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The Part Many DIY Repairs Miss: Diagnostics

This is where a simple battery replacement becomes a proper VCM repair.

Installing the battery is only the physical part.

After the VCM has been reinstalled, the vehicle should be scanned again.

If the original fault was U105000 or another battery-related VCM code, follow the applicable diagnostic procedure.

Depending on the vehicle and fault, software updating, module programming, fault clearing or other service operations may be required.

In other words:

New battery ≠ automatically completed repair.

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Why the Warning May Remain After Installing a New Battery

Imagine the following situation.

You install a new XCS67890L compatible battery.

The VCM is reinstalled.

The vehicle starts normally.

But the dashboard still says:

“Volvo On Call Service Required.”

That does not automatically mean the new battery failed.

Several possibilities remain:

Incorrect battery

The replacement may not match the actual VCM configuration.

Connector problem

The battery connector may not be fully seated.

Existing fault code

The original diagnostic condition may still be stored.

Software requirement

The VCM may require the applicable software procedure.

Different VCM problem

The warning may have another underlying cause.

The correct response is to scan the VCM again rather than repeatedly replacing parts.

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What About Older Volvo Models?

The battery issue becomes particularly relevant when dealing with older Volvo vehicles.

The 31350776 application has been associated with platforms including:

• S60

• V60

• V60 Cross Country

• S80

• V40

• V40 Cross Country

• V70

• XC70

• XC60

• XC90

But model name alone is not enough.

A Volvo XC90 from one production period may have a different telematics configuration from another XC90.

The same applies to S60, V60, XC60 and other model lines.

Therefore, the Volvo 31350776 Battery should always be checked against the exact vehicle configuration.

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Don't Confuse Battery Failure With Network Shutdown

There is another important distinction for owners of older Volvos.

Replacing the VCM battery cannot bring back a cellular network that has been shut down.

Some older Volvo On Call systems relied on 3G connectivity.

Where 3G service has been discontinued, certain connected functions may no longer operate even if:

• The vehicle's main battery is healthy.

• The VCM is functional.

• The backup battery is new.

• The dashboard warning has been addressed.

Therefore, before spending money on extensive telematics repairs, owners of older vehicles should also consider the communication technology used by their specific VCM and the network situation in their market.

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Is a 4V / 600mAh Battery Enough Information?

No.

This is one of the most important purchasing lessons from this type of repair.

Suppose two batteries both have approximately the same voltage and capacity.

That does not automatically make them interchangeable.

You still need to consider:

Connector

Pin configuration

Polarity

Physical dimensions

Protection circuit

Battery chemistry

VCM compatibility

For that reason, a product page such as the TLM-1550 replacement battery should be evaluated against the original battery rather than selected from voltage and capacity alone.

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What I Like About the Replacement Approach

From a repair perspective, the biggest advantage of replacing the internal battery is that it targets the suspected failure point.

If diagnostics establish that the problem is the VCM backup battery, replacing the battery can be considerably more targeted than immediately replacing the complete VCM.

It also makes sense for older vehicles where owners want to maintain an otherwise functional car without replacing expensive electronic modules unnecessarily.

The VCM Backup Battery approach is therefore particularly relevant for technicians and experienced DIY owners who can correctly identify the VCM and perform the required diagnostic work.

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What I Would Check Before Buying

Before purchasing a replacement, I would make the following checklist mandatory.

Vehicle information

Record:

• Model

• Production year

• Market

• VIN

VCM information

Record:

• VCM part number

• Software version where available

• Existing fault codes

Battery information

Record:

• Original part number

• Battery voltage

• Capacity

• Connector

• Polarity

• Dimensions

Cross-reference numbers

Check whether the original battery corresponds to:

31350776

XCS67890L

TLM-1550

If these identifiers do not correspond to the original component, do not assume the battery is compatible.

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Volvo 31350776 Battery: Who Is This Replacement For?

This type of replacement makes the most sense for several groups of Volvo owners.

Owners of older Volvo vehicles

If the vehicle is still mechanically sound but has developed a VCM backup-battery warning, replacing the battery may be worth investigating.

Automotive electronics technicians

A dedicated replacement battery provides a specific service component rather than requiring modification of a generic rechargeable cell.

Volvo DIY enthusiasts

Experienced owners who are comfortable removing interior trim, handling electronic modules and using diagnostic equipment may find the repair manageable.

Independent repair shops

A dedicated replacement can be useful when servicing older Volvo VCM systems where battery-related faults are confirmed.

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Final Review

The most interesting thing about the Volvo VCM backup battery is how such a small component can create a surprisingly noticeable warning.

The vehicle may drive normally.

The engine may start normally.

The main 12V battery may be fine.

Yet the VCM can still report a backup-battery problem.

For the relevant Volvo configuration, the Volvo 31350776 Battery provides a focused replacement option rather than automatically replacing the complete VCM.

The TLM-1550 and XCS67890L identifiers can also help when searching for the appropriate replacement, provided they match the original application.

The most important conclusion is simple:

Diagnose first, verify the part number second, replace the battery third, and complete the required diagnostic/software procedure afterward.

A VCM backup battery is not a generic car battery, and a Volvo VCM is not a component that should be disassembled casually. But when the diagnosis points specifically to an aging backup battery, replacing that small component can be a much more targeted approach than immediately replacing the entire communication module.

For owners researching a Volvo 31350776 Battery, TLM-1550, XCS67890L, or VCM Backup Battery, checking the original component against the replacement specifications is the most important step before ordering.