vauxhall insignia code 3

Code 3 Vauxhall Insignia [Meaning, Causes & Fix]

In this article, I will explain what “code 3” means on a Vauxhall Insignia, the leading causes, and how to reset the fault. let’s get to it.

Code 3 on Vauxhall Insignia Meaning

In short, code 3 on a Vauxhall Insignia is a fault message that means the system has detected low coolant levels. This can be caused by either a leak somewhere in the cooling system or insufficient coolant.

Now, let’s look at the possible causes for a “code 3” on Vauxhall Insignia.

Vauxhall Insignia “Code 3” Main Causes

From my experience as a technician, I’ve found the following to be common causes of “code 3” on a Vauxhall Insignia.

Cracked Coolant Reservoir 

The most common cause for a code 3 on an Isignia is a cracked coolant reservoir container.

This is the part of the car that holds the coolant, and it looks like a big plastic bottle with hoses attached to it.

The coolant reservoir can crack from age or due to everyday impacts such as speed bumps and potholes.

Unfortunately, these water bottles found in an Isignia are prone to cracking. When this happens, coolant can leak out and cause a code 3 fault on your Vauxhall.

The first thing I recommend that you do when “code 3” comes up on your dashboard, is to look for signs that your coolant reservoir is leaking.

If you see a puddle of coolant under your Isignia, then this part of the car needs to be replaced.

Bad Coolant Reservoir Cap

Other than a cracked expansion tank, the cap could also be the reason why you have a “code 3” fault on your Vauxhall.

If this cap is damaged or defective, it may not seal properly and allow coolant to leak out.

I recommend checking your coolant reservoir cap to see if it’s showing any signs of wear such as cracks or other damage.

Since the coolant reservoir cap controls the pressure it’s important that it stays in good condition.

Insufficient Coolant

Over time, engine coolant flows throughout the car and is used up. When this happens, you will need to top it off every few months.

If it has been a long time since you last checked the coolant level and it’s low, then you will need to add more. I recommend having the coolant system flushed every two years or so in addition to topping off the fluid regularly.

Water Pump Failure

Another reason why your Vauxhall may have a code 3 fault is because of a failed water pump.

The water pump circulates coolant through your engine block and radiator core in order to maintain an ideal temperature range for efficient operation.

Although the water pump rarely fails on Vauxhall Insignias, it is possible for it to happen.

Radiator Leak

The last common cause of the Vauxhall Insignia code 3 fault, is a damaged radiator that is leaking coolant.

You will know if your radiator is leaking due to a puddle of fluid under your car, or by noticing steam coming from the engine.

If this happens, it’s time to have your vehicle towed to the nearest Vauxhall dealership for repair as soon as possible!

Radiator leaks are normally caused by corrosion and rust that builds up over time but can also be caused by external objects such as stones, hitting the radiator.

How to Fix “Code 3” on a Vauxhall Insignia

Finally, let us get to how to fix and reset Vauxhall Insignia Code 3.

The first thing you need to do is check your coolant level. If it’s low, top up with a 50/50 mix of water and antifreeze.

If you see that the coolant is disappearing faster than normal, check for leaks by inspecting the radiator cap and reservoir.

Look for any signs of damage or corrosion. If your coolant bottle hasn’t been damaged, then you should check the radiator hoses and pipes for leaks.

If everything looks good there then you can move on to check the water pump and thermostat housing.

After you topped off the coolant to the required level and there are no leaks, then you simply need to disconnect and reconnect your battery to reset the system.

The “Code 3” should disappear. If not, then you should take your car to a mechanic to have them diagnose the issue and repair it.

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