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Engine-Codes – GMC – P0603 2016 GMC Sierra

P0603 2016 GMC Sierra Code - Control Module Long Term Memory Reset

Quick Answer

The P0603 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates a control module long term memory reset. Common causes include Faulty ECM/PCM, Weak or dead battery, Loose or corroded battery connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0603 2016 GMC Sierra indicates Control Module Long Term Memory Reset.
Common causes
Common causes include Faulty ECM/PCM, Weak or dead battery, Loose or corroded battery connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code P0603 2016 GMC Sierra Description

The P0603 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates a control module long term memory reset. This code is triggered when the Engine Control Module (ECM) or Powertrain Control Module (PCM) detects that its long-term memory has been reset. The ECM/PCM is responsible for storing various data and settings related to the vehicle's operation, including fuel mixture, ignition timing, and emission control systems.

OBDII Code P0603 2016 GMC Sierra - Control Module Long Term Memory Reset
P0603 2016 GMC Sierra Code - Control Module Long Term Memory Reset

Common Causes of P0603 2016 GMC Sierra

  1. Faulty ECM/PCM
  2. Weak or dead battery
  3. Loose or corroded battery connection
  4. Power surge or electrical issue

Symptoms of P0603 2016 GMC Sierra

  1. Poor fuel economy
  2. Rough idling
  3. Hesitation during acceleration
  4. Stalling
  5. Vehicle going into limp mode

How to Fix P0603 2016 GMC Sierra

  1. Check the battery voltage and connection to ensure they are in good condition.
  2. Perform a diagnostic scan to identify the specific issue causing the long-term memory reset.
  3. Reset the ECM/PCM and reprogram it with the correct data.
  4. If necessary, replace the ECM/PCM with a new unit.
  5. Test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P0603 2016 GMC Sierra

The typical repair costs for addressing a P0603 code in a 2016 GMC Sierra can range from $200 to $500, including parts and labor. However, it's important to note that the specific diagnosis time and labor rates at auto repair shops can vary based on various factors. It's advisable to check with local shops for a more accurate estimate.

What does this mean?

Tech Notes for P0603 2016 GMC Sierra

Start by charging the vehicle's battery and clean terminal, once the battery is charged and the terminals are clean and secured, erase the code. If the code comes back ON, then you may have to reprogram or replace Powertrain Control Module (PCM).

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0603 2016 GMC Sierra Code

1. What does the OBDII code P0603 mean on a 2016 GMC Sierra?

P0603 indicates that the Powertrain Control Module (PCM) has detected an issue with its long-term memory, often due to a reset or loss of stored data.

2. What are the common symptoms of code P0603 in a 2016 GMC Sierra?

Symptoms may include an illuminated check engine light, erratic vehicle performance, difficulty starting, or loss of custom PCM settings.

3. What causes the P0603 code to appear?

Common causes include a weak or disconnected battery, faulty PCM, poor electrical connections, or aftermarket performance tuners.

4. Can a weak battery cause code P0603 in my GMC Sierra?

Yes, a weak battery or power interruption can reset the PCM’s memory, triggering the P0603 code.

5. How do I fix the P0603 code on a 2016 GMC Sierra?

Start by checking the battery and its connections. If they are fine, inspect the PCM wiring or consider reprogramming or replacing the PCM if necessary.

6. Will a performance tuner trigger the P0603 code?

Yes, aftermarket performance tuners can sometimes interfere with the PCM's memory, causing the P0603 code.

7. Is it safe to drive my 2016 GMC Sierra with a P0603 code?

While the truck may still operate, driving with a P0603 code can lead to poor performance or potential damage if the underlying issue isn’t resolved.

8. Can clearing the P0603 code solve the problem?

Clearing the code may work temporarily, but if the cause isn’t addressed, the code is likely to return.

9. How much does it cost to fix the P0603 code on a 2016 GMC Sierra?

Costs can vary widely depending on the cause. Battery or wiring repairs are relatively inexpensive, but PCM replacement or reprogramming can cost several hundred dollars.

10. Can a loose ground connection cause the P0603 code?

Yes, a loose or corroded ground connection can disrupt the PCM’s memory and trigger the P0603 code.

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