Can a Dying Battery Cause the Check Engine Light to Come On?

Photo: Emmerling

A dying, fading car battery means low voltage. As a result, your car’s computer, which is responsible for reporting error codes, is also receiving low voltage.

An error code will be generated which will in turn trigger the Check Engine Light or even the Battery Charge Warning Light to display.

So what should you do?

How do you know if a dying battery is actually the cause of the warning light to come on? And if not, what could be the problem? Is there an engine light diagnostic app you can use?

Let’s find out…

What the Dashboard Light Means

Example image of a Check Engine Light or Malfunction Indicator Lamp (MIL)
Example image of a Check Engine Light or Malfunction Indicator Light (MIL)

When the check engine light comes on, it will either blink / flash or remain solid / steady, depending on the severity of the problem.

Some of the common warning indicator labels are:

  • Or just a pictogram (icon) of an engine outline

You can either pop the bonnet and reset the battery terminals or use an OBD2 Scanner to clear the error codes via your smartphone.

Let’s look at each light symbol in detail.

Flashing / Red Check Engine Light

A red (rather than yellow/orange) or flashing light on your dash signals a serious issue that needs urgent attention.

A blinking / red check engine light means there could be a serious engine misfire and unburnt fuel is being dumped into the exhaust system.

This is a serious problem that can cause damage to your car components, such as the catalytic converter, which is costly to repair.

(Consider that a catalytic converter costs between $500 and $1,000 each and there are multiple units within a vehicle.)

Flashing check engine light
If the warning light is flashing, it’s serious

What to do when the Check Engine Light is flashing?

When you see a blinking light on your dashboard, do not to attempt driving your car any further.

Continuing to drive with a flashing check engine light is a critical mistake that can cause extensive damage to your car.

So, slow down, safely pull over to the kerb, and have your car towed to an automotive repair shop as soon as possible.

Your mechanic will run an OBD2 diagnostics check. To confirm the mechanic’s results you can use an OBD2 compliant diagnostics app such as GOFAR.

Steady / Solid Check Engine Light

If the check engine light is on but steady / solid, it’s okay to keep driving because it’s not an emergency.

However, if you keep driving around with a steady check engine light on, your car’s performance may deteriorate without you noticing.

In the process, you may suffer expensive fuel mileage. Plus, your car could be emitting hydrocarbons and other pollutants at unacceptable levels.

What to do when the Check Engine Light is solid?

You need to diagnose the problem as soon as you can to avoid things getting worse.

You can use an OBD2 scanner (also called an OBDII scanner) – like mechanics use – to check the fault code generated by the car’s computer.

OBD stands for On-Board Diagnostics, and most modern cars have OBD2 ports near the steering wheel to access them. Or you could pay your mechanic to do that for you. Either way, you should do something.

Quick Solution: GOFAR app automatically diagnoses the problem and can save $1,000s in costly car repairs. Features or Buy Now

Battery Charge Warning Light

Battery Charge Warning Light symbol
GOFAR diagnoses 300+ common OBD2 scanner code errors – Get yours today

If this light comes on, it definitely indicates a malfunctioning or poorly charging battery.

This warning light illuminates whenever the charging system isn’t charging the battery with at least a voltage of around 13.5 volts.

This particular warning can be triggered by a range of issues, so check with a professional to find out what the exact issue is before spending money on parts that don’t necessarily need replacing.

Tips to Determine Why Your Check Engine Light Is Illuminated

Firstly, Decide Whether There’s a Serious Problem

A serious problem requires immediate attention, otherwise you risk more damage to your car. Therefore the best place to start checking is your car’s dashboard array.

The dashboard gauges and lights are good indicators of serious problems such as low oil pressure or overheating.

If you discover that your oil pressure is low or there’s overheating, you need to quickly find a safe place, pull over, and shut off the engine.

Remember a yellow check engine light gives you some time to investigate the problem. But, a red or blinking light means it is an emergency and you should immediately but safely pull over.

You can diagnose dashboard warning lights with GOFAR.

Inspect for Loose Fuel Cap and Tighten or Replace as Necessary

BMW battery charging
Image from: GoranH

It may sound obvious but a loose/faulty gas cap can actually set the check engine light on. Some vehicle models – including the Honda CR-V – have a separate fuel cap warning indicator on the dash.

Either way, if the issue is a loose gas cap, even after fixing it, you may need to drive for about 50 to 100 miles (80 to 160 km) before the check engine light resets.

Use the GOFAR Code Scanner

Your car is capable of performing remote diagnostics and report trouble codes. But, you will need a code scanner such as GOFAR.

Best of all, you don’t need any technical knowledge to use GOFAR.

Once you plug it into your dash, it will read, interpret, and report to you your car issues in plain English. GOFAR has the capability to diagnose over 300 common car issues.

Test Your Car’s Battery

Most car problems emanate from a faulty/undercharged battery or a poor electrical connection. With a faulty battery, there’s bound be low voltage at the car’s computer which may cause the check engine light to come on.

When you take your car to the mechanic, he will test your car’s battery before doing any further diagnostic testing.

Reduce Speed and Load

Let’s say you are towing a trailer and then the check engine light suddenly comes on.

A great idea would be to stop towing the trailer and have the car checked for possible damage.

So, if you notice your check engine light is blinking or your car is underperforming and losing power, you need to reduce your speed and the demands on the engine.

Replace Faulty Spark Plug Wires and Spark Plugs

red and black battery jumper
Image from: StockSnap

If your spark plugs or wires are damaged they can cause serious engine misfires, hard starts and poor fuel economy along with emitting a higher amount of harmful emissions.

For every 30,000 miles (50,000km) covered, you need to need to replace your spark plugs and spark wires. Otherwise, when fouled, they will cause the check engine light to come on.

Replace Bad Ignition Coil(s)

An ignition coil is known as a spark coil. It boosts the battery’s low voltage to the required volts (in thousands) needed to create an electric spark and ignite the fuel.

Since the ignition coil is part of your car’s ignition system, any fault will cause the check engine light to come on.

Replace Faulty Fuel Injector(s)

A fuel injector is used to deliver fuel into the engine via a nozzle. The engine control unit (ECU) determines the frequency the fuel is injected into the cylinder.

For every 30,000 miles covered (50,000km), the fuel injectors should be cleaned to avoid clogging.

Nonetheless, the fuel injectors can become faulty and light up the check engine light, as can other problems such as:

  • Violent/ Rough engine idle
  • Gasoline/fuel leaks
  • Poor fuel economy
  • Unburned fuel odour
  • Engine surges
  • Misfiring engine
  • Vibrating engine

Replace Bad Mass Air Flow (MAF) Sensor

The mass air flow sensor regulates the mass of air getting into the fuel injection engine. It then reports the same to the Engine Control Unit (ECU).

When the mass air flow sensor is faulty there won’t be correct balance and delivery of fuel to the engine.

To boost your engine performance and turn off the check engine light, take it to a qualified mechanic for repair.

Keep in mind that it’s much easier to use a GOFAR to diagnose the exact problem. This is an affordable DIY gadget that explains all your car’s problems in plain English.

There are more car issues that can cause the check engine light to come on. Here is a comprehensive list of some of the main culprits:

  • Replace Crankshaft Position Sensor
  • Replace evaporative emissions canister vent valve
  • Replace intake manifold gaskets
  • Replace evaporative emissions vent control
  • Replace engine coolant temperature sensors
  • Replace emission system integrity monitor
  • Clean fuel injectors
  • Replace spark plugs
  • Replace knock sensors
  • Replace throttle body assembly
  • Replace fuel tank pressure sensor
  • Replace Evaporative Emissions (EVAP) Canister Vent Solenoid
  • Replace Camshaft Position Sensor (CMP)
  • Replace Exhaust Gas Recirculation (EGR) Valve and Clean All EGR ports
  • Replace Evaporative Emissions (EVAP) Purge Solenoid
  • Replace Thermostat
  • Replace Evaporative Emissions (EVAP) Purge Control Valve
  • Replace Catalytic Converter(s) with new OE Catalytic Converter(s)
  • Replace Oxygen Sensor(s) (O2S

In Conclusion

It can be hard to know what the engine warning light is telling you. Luckily, GOFAR provides a reliable and safe solution.

Install GOFAR in your car to receive plain English error codes on over 300 common issues with your car.

You can check whether your car is GOFAR-ready or learn more about understanding your car engine warning lights on the spot.

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