Getting the dreaded Code 174 is a common occurrence on the Vauxhall Astra and other Vauxhall models from my experience, but it doesn’t have to be cause for concern.
In this article, I am going to explain what Code 174 is, why it occurs, and how you can fix it. Let’s get to it.
What Does Code 174 Mean on a Vauxhall Astra?
In short, code 174 on a Vauxhall Astra indicates that the Electronic control unit has detected a low battery voltage.
In other words, the battery is not holding its charge.
As a result, the ECU has detected that there is insufficient power to run certain systems in your car, so it throws the code 174 to alert you before your Astra runs out of juice completely.
What Causes Vauxhall Astra Code 174?
Now, that I have explained that the code means your battery voltage is too low, let’s look at the possible causes for this.
You Don’t Drive Enough to Charge the Battery
If you park your car for a long time without driving it, the battery will discharge and cause code 174.
In fact, even if you drive your car every day but don’t get enough miles on the clock to fully charge the battery, this can also cause code 174 to appear in your Vauxhall Astra.
Since the alternator is what charges your battery, if it doesn’t get enough use to fully charge the battery, then you’ll end up with a low voltage.
Bad Battery
Another common cause for a low battery voltage on a Vauxhall Astra from my experience is a bad battery.
If your car is more than a few years old, it’s possible that you have to replace the battery and it just isn’t holding its charge anymore.
A bad battery can also cause other electrical issues in your Vauxhall Astra like trouble starting or turning over.
The Battery on your Astra has a lifespan of 3-5 years and will slowly begin to hold less of a charge over time. If your battery is more than 3 years old, it may be time to replace it.
Corroded or Loose Battery Terminals:
Corroded or Loose battery terminals can cause a low voltage issue with your car.
This happens because when the terminals are corroded, they can’t conduct electricity properly.
So they send less power to the battery than they should.
Also if your battery terminals become loose for whatever reason, they’ll also cause a code 174 to come up since the battery is draining more than it charges.
Faulty Alternator
The alternator on Vauxhall Astra’s is notorious for going bad and not working as well as it used to.
This happens over time as part of the wear and tear of the vehicle
This can lead to a code 174 coming on your Astra’s dashboard because the alternator is what charges the battery when you’re driving around town or on highways.
Cracked or Slipping Serpentine Belt (Drive Belt):
The serpentine belt is what turns your alternator, air conditioner compressor, and power steering pump.
Without this belt, those components will stop working. If it cracks or slips off of its pulleys, it can’t turn properly and cause your alternator to not work properly.
This will cause the battery to lose charge and code 174 will come up once the battery reaches a certain percentage on your Astra.
Other Low Battery Voltage (Code 174) Signs on a Vauxhall Astra
Other than the code 174 displaying on your Astra there are a few other signs that your battery is low.
The first is your headlights will start to dim. You will notice this the most when driving at night and when you flip on your high beams.
Another common sign of a low battery voltage on a Vauxhall Astra is your radio will start to cut out or switch off after a few minutes.
Clicking sound and Hesitant Start on a Vauxhall Astra is Another sign of a low battery voltage.
When you try to turn over the engine but it seems like it’s struggling and won’t start and makes a clicking noise while the dash lights are flickering.
The air conditioner may not work, and the interior lights will be dim.
How to Fix and Reset Vauxhall Astra Code 174?
Now that I have explained what code 174 on your Astra means and the main causes, let’s look at how to fix and reset this fault code.
1. Charge Your Battery
If your battery is still in decent condition and just lost volts due to inactivity or cold weather, you will need to get it charged in order to clear the code 174 from your dash.
You have a few ways to go about getting your Vauxhall Astra battery charged, here is what I recommend:
- Using a portable battery charger
- Using a portable battery jump starter
- Getting someone to Jumpstart to you
- Take your battery to any Auto shop and have them charge it for you
After charging your battery, code 174 will clear on its own.
2. Replace Your Battery
If your Battery is old and doesn’t properly hold a charge anymore then you will need to replace it.
You can find and purchase a new battery for your Astra at any Vauxhall dealership, Auto Parts store, or online.
If you plan to order it online then make sure that you get the right size, as a mechanic I often see people ordering the wrong battery for their Car.
The battery size is printed on a sticker near the bottom of your car’s engine and should be easy to find.
3. Have the Alternator Tested
If charging the battery and/or changing it doesn’t fix the 174 code on your Astra then you may have an alternator issue.
The alternator is the device that charges your car’s battery and, if it’s not working properly, can cause this error code to appear.
If you suspect that your alternator needs to be replaced then take it to a mechanic and get them to test it out for you.
Additional Sources
https://www.vauxhall.co.uk/owners/maintenance-and-repair/repairs.html
https://www.batteriesplus.com/blog/power/car-battery-care
https://www.autozone.com/diy/battery/how-long-should-a-car-battery-last