Handling Volvo Truck Light Control Module Problems? Fix It!

Volvo truck light control module problems cannot only lead to irregular lighting situations on the road. For example, flickering headlights and malfunctioning brake lights. It is often found near the dashboard. The most general troubleshooting involves checking fuses, resetting the module, or replacing it completely.

Having a malfunctioning LCM system is not only bad news for your truck but also for the other people driving on the road. Compromised lighting can eventually mean compromised safety and visibility.

But you don’t have to worry, as I’ve developed this basic guide on handling LCM failure with the most straightforward steps. Keep reading…

Volvo Truck Light Control Module Problems – Initial Overview

It’s no doubt that the Light Control Module, also known as LCM, is a significant element of Volvo trucks that has the job of overseeing all lighting functions. But exactly what does the light control module control?

The light control module in the Volvo truck controls the headlights, taillights, brake lights, turn signals, hazard lights, and even the fog lights. Apart from the lights, the LCM is also in charge of controlling the horn. So clearly, malfunction in LCM leads to several lighting issues.

Where is the lighting control module located in Volvo trucks?

The location of the LCM in Volvo trucks can vary. However, typically it is located right in in the center of the dashboard. You should find it under the upper cup holders, and directly beneath the fuse panel.

This is the case for VNL semi-trucks, more specifically. To confirm that you are having problems with the LCM, there are some symptoms to look forward.

Signs That Your Volvo Truck Is Having Light Control Module Problems:

• You’ll find the headlights to turn on and off unpredictably. Or perhaps they won’t work at all.
• It’s possible that one or all tail lights stop working.
• The emergency hazard lights will start to blink too quickly or not function at all.
• Sporadically working brake lights.
• Important gauges will be hard to read due to the failure of dashboard lights.
• Blinking turn signals.

Once you confirm that the LCM does need some attention consider not driving the truck until it is fixed. This is because the LCM is responsible for maintaining visibility and communication with other drivers.

It could get quite unsafe, especially during poor weather conditions or at night. In some areas, driving with problematic lights can result in severe traffic violations and fines. Yes, functional lights are a legal requirement in most areas.

Here’s a general troubleshooting guide you can use to fix any minor problem with the LCM and get the truck back to work.

Step 1 – Doing The Initial Checks and Diagnostics

A visual inspection can help you note down any obvious signs of damage or corrosion. And you want to focus mainly on the Lighting Control Module (LCM) as well as its connectors.

There should be the fuse associated with the LCM that you want to check well. Go ahead and replace any blown fuses and see the right way if this resolves the issue. It could also be related to an instrument cluster problem with the Volvo truck. 

After this, you should also try resetting the LCM. It’s quite simple process that needs disconnecting the truck’s battery for about 30 minutes. Next, you simply reconnect the battery and test the lights. And if the reset is enough of solution, the light should start working.

Sometimes what makes the LCM problematic is it lacks a proper ground connection. To verify you need nothing but a jumper cable. Simply connect it to the battery ground to a ground lug on the firewall. Check the system.

Step 2- Consider Replacing or Repairing the LCM

Let’s say you determine that you need to replace the LCM. The process will need you to carefully pry up the cover of the LCM. 

You can use any regular screwdriver for this. Next, you should loosen the bolts securing the LCM. You must also disconnect the wiring harness.

Now bring a new or refurbished LCM. Make sure it is well compatible with your Volvo truck model. You must connect the wiring harness to the new LCM. Go ahead and secure it with the bolts. Next, you want to replace the cover. Finally, reconnect the battery.

And that’s all for the installation. Now the new LCM must be programmed. For this, you should consider taking the vehicle to a Volvo dealership or a certified technician. Without proper programming, the LCM won’t be able to work with the truck’s specific lighting setup.

Important – Usually for a new LCM, you can expect an expense between $250-$300 for parts.

Step 3 – Work On These Additional Considerations

As soon as you have the LCM programmed, you should also think about any lighting upgrades or additions. This could be something as simple as switching to LED lights.

Experts at Trucks and Moore suggest that switching to LEDs brings better visibility and you can keep them on longer without draining your battery. They can last up to 50,000 hours, which is way longer than regular bulbs.

You can also consider adding fog lights. Having said that, these changes during the initial programming may require some cost addition but in the long run, would be reasonable.

Tips On Addressing Other Lighting Issues

• If you find out that the turn signals are not working, check the bulbs. Consider replacing any that are blown. You should also inspect the turn signal relay and replace it if faulty.
• It is possible that you are also facing inconsistent brake lights. In this case, give attention to the bulbs and make sure those are functional. You must also check the brake light switch and wiring for damage or corrosion.
• Did you find the dashboard lights not illuminating as well? In that case, you should have a look at the dimmer switch. You can’t miss any loose or damaged wiring behind the dashboard.
• Make sure there are no starting issues such as the “start prevented, try again” message that you did not pay attention to. It could also be an ignition switch problem that was minor at first.

Wrapping Up

And that’s all for a guide to help you do a simple easy troubleshooting for Volvo truck light control module problems. Before I leave, there’s something that I can’t emphasize enough. 

That one thing people miss out. Maintenance! Please be more prompt with regular maintenance and repairs. Don’t leave it for later. You should regularly inspect the LCM and its wiring. I would also suggest keeping the truck’s interior dry as this helps to avoid moisture-related damage. 

Once in a while, even if the truck is not being used, try to test all lights to make sure they are still functioning. LCM-related issues are often handled with a straightforward replacement. 

However, things could be more complicated underneath. So don’t be late with calling a professional if things seem not manageable for you alone.

I will see you in my next guide!