How to Fix Code P0562: System Voltage Low

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an OBD scanner with code P0562 on the screen

If you're driving and suddenly your car starts to sputter, one of the first things you'll want to do is see if the Check Engine Light is on. If it is, there's a good chance that you'll see a P0562 error code. It could cause you to panic but don't worry! 

This blog post will talk about what causes this error code, the symptoms you might experience, and some possible fixes.

What is Code P0562?

Code P0562 is a generic powertrain/engine diagnostic trouble code that refers to "Systems Voltage Low." It applies to all 1996 newer vehicles (OBD-II). When the Power Control Module (PCM) detects the ignition feed circuit is not working, and the voltage is too low, code P0562 will be triggered.

Symptoms of Code P0562

Like other error codes, the P0562 code triggers the malfunction indicator light. And since this error code occurs due to a low voltage situation, you may experience any symptoms such as:

  • Illuminated red battery light
  • Transmission may not shift.
  • The engine may not start.
  • Engine stalling
  • Lower fuel economy

Causes of Code P0562

As this error code is associated with many symptoms, it can be challenging to determine the root cause. However, there are a few causes that you can look at to help fix the issue. These include:

  • Defective alternator
  • Damaged electrical connectors
  • Faulty wiring
  • Faulty B+ battery
  • Not operating charging system ground(s)
  • Faulty PCM
  • Defective wiring/connection to the alternator
  • Faulty voltage regulator

How to Diagnose Error Code P0562?

If you notice and feel any of the symptoms listed above, it is crucial to diagnose your car. This will help determine the root cause of the error code and what needs to be done to resolve it. Some standard methods used for diagnosing this code include:

Visual Inspection

  1. Inspect the wirings and electrical connectors and ensure they are all in good condition.
  2. Check the belt alternator and make sure it is properly tightened.

Testing the Voltage Output

  1. Start the engine.
  2. Turn the headlights and blower fan on and set it to high speed to load the electrical system.
  3. With the engine running, measure the voltage across the battery terminals. It should be between 13.75 and 14.75 volts. If it is not within this range, there may be a problem with the alternator or charging system.

If the result of the voltage output is normal, use an OBD scanner to clear the trouble codes and see if the p0562 code will appear. The absence of the error code means there is no need for further diagnosis. But if the code still shows, move on to checking the PCM.

Check the PCM

  1. Locate the PCM on your car and inspect it visually.
  2. Examine the connections and wiring for scraping, rubbing, bare wires, burn scars, or melted plastic while looking for this.
  3. Disconnect the connectors and carefully review the terminals (metal components) inside them.
  4. Check if they look burned or have a green tint indicating corrosion.

Check the Voltages to the PCM

  1. Before you start, disconnect the negative battery cable from the battery first and disconnect the PCM harness.
  2. Connect the battery cable again. Start your car and switch on the ignition.
  3. Connect a test light to 12V battery positive (red terminal) and touch the other end of the test light to the ground circuit going to the PCM ignition feed circuit ground.
  4. Check if the test light does not light up. This indicates a problem in the circuit. If it lights up, check the wiring harness to the PCM to see if the test light flickers; if so, it means an intermittent connection.

If all previous tests have passed and you continue to get a P0562 code, this would most likely indicate a failed PCM.

How to Fix P0562 Code?

Because there are many potential causes of this error code, there is no one-size-fits-all solution. Depending on the root cause, some possible fixes include:

  • Replacing a bad alternator
  • Replacing the PCM Power Control Module
  • Replacing a voltage regulator

If you are uncomfortable attempting any of these repairs yourself, it is always best to take your vehicle to a qualified technician. However, if you are confident enough to fix yourself, you can follow these step-by-step guides.

Step-by-Step Guide to Replacing the Alternator

It is not as difficult as you think when replacing a bad alternator, but it still requires a bit of automobile knowledge. If you are ready, let’s get started.

What you'll Need:

  • Car alternator
  • Hand tools
  • Voltmeter
  • Belt
  • Rags
  • Gloves
  • Masking tape
  • Memory saver (check your manual)


  1. Use the memory saver to save all the settings and electronic info.
  2. Disconnect the negative battery cable.
  3. Check the belt and identify if it is a serpentine or V belt.
  4. Locate the belt tensioner and loosen the serpentine belt
  5. Remove the belt
  6. Remove the wiring harness, connectors or wiring, and fasteners from the alternator. 
  7. Remove the alternator.
  8. Install the new alternator and tighten all fasteners.
  9. Reinstall wiring harness, connectors, or wiring and fasteners to the alternator.
  10. Route and tension belt according to your car's manual specs.
  11. Tighten belt tensioner.
  12. Reconnect the negative battery cable.
  13. Connect the voltmeter to the battery and start the vehicle.
  14. Check if the voltage is in a normal range. It should be between 13.1 to 16.5 volts. If everything looks OK, your alternator replacement job is complete.

Step-by-Step Guide to Replacing a Voltage Regulator 

Suppose you're experiencing symptoms such as flickering or dimming headlights, a dead battery, difficulty starting your car, or a "Check Engine" light. In that case, you might need to replace your voltage regulator. To perform it:

  1. Disconnect the negative battery cable.
  2. Remove the belt tensioner and loosen the alternator belt.
  3. Remove the three bolts that secure the alternator to the engine block.
  4. The voltage regulator is located on top of the alternator. Remove the old one and replace it with a new one.
  5. Reinstall everything in reverse order.

Common Mistakes When Diagnosing the Code P0562

Because of many causes associated with the code P0562, some people neglect to diagnose possible reasons for this issue. Some of the common mistakes people make are:

  • Assuming that the alternator is defective, resulting in unnecessary replacement.
  • Not checking for damaged electrical connectors
  • Failure to inspect for faulty wiring
  • Not checking if the charging system is working properly
  • Replacing the PCM when the real cause is the alternator.

Code P0562 FAQs

1. Is the code P0562 code serious?

No, it's not a serious code. It just means that your alternator isn't putting out the correct voltage. However, it can lead to a more severe issue if you leave it unaddressed.

2. What does it mean when the system voltage is low?

When the system voltage is low, the battery is not charging correctly. This can be caused by many things, including a bad alternator or a problem with the wiring.

3. How do I know if my alternator is bad?

You will know if your alternator is bad or not functioning correctly if it is not putting out the right voltage.

4. Is it safe to drive with code P0562?

Yes, it's safe to drive with code P0562 as long as you address the issue. However, if you leave it unaddressed, it could lead to a more severe problem.

5. How much does it cost to repair this error code?

The repair cost depends on the make and model of your car. However, the ideal range is $120 to $150.


The code P0562 can cause headaches, especially when it is associated with many symptoms. But don't worry because even though its causes are many, the fixes are straightforward. So if you're experiencing any of the signs mentioned, it's best to diagnose and get it fixed as soon as possible.

That's all for today! We hope this article was helpful and provided you with information on what to do if your car starts displaying the code P0562. Thanks for reading, and don't hesitate to reach out if you have questions or comments.