AutoCodes – GMC – P0603 2014 GMC Sierra

P0603 2014 GMC Sierra Code - Control Module Long Term Memory Reset

Quick Answer

This diagnostic applies to internal microprocessor integrity conditions within the Engine Control Module (ECM). Common causes include Low battery voltage, Reprogram Engine Control Module (ECM), Faulty Engine Control Module. 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 2014 GMC Sierra indicates Control Module Long Term Memory Reset.
Common causes: Common causes include Low battery voltage, Reprogram Engine Control Module (ECM), Faulty Engine Control Module.
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.

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Code Popularity 322

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 29, 2024

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0603 2014 GMC Sierra Description

This diagnostic applies to internal microprocessor integrity conditions within the Engine Control Module (ECM). This diagnostic also addresses if the ECM is not programmed. The ECM monitors its ability to read and write to the memory. It also monitors a timing function. No external circuits are involved. The Diagnostic Trouble Code (DTC) will be set when the ECM detects an internal failure or incomplete programming for more than 10 s.

OBDII Code P0603 2014 GMC Sierra - Control Module Long Term Memory Reset - AutoCodes.com — P0603 2014 GMC Sierra Code - Control Module Long Term Memory Reset

What does this mean?

What are the Possible Causes of the DTC P0603 2014 GMC Sierra?

Low battery voltage
Reprogram Engine Control Module (ECM)
Faulty Engine Control Module
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection

How to Fix the DTC P0603 2014 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

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).

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0603 2014 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0603 2014 GMC Sierra code?

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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 2014 GMC Sierra Code

1. What does the OBDII code P0603 mean on a 2014 GMC Sierra?

P0603 indicates a "Control Module Long Term Memory Reset," meaning the Engine Control Module (ECM) has lost its stored memory, possibly due to a power interruption or internal issue.

2. What are the common symptoms of code P0603 on a 2014 GMC Sierra?

Symptoms may include an illuminated check engine light, reduced engine performance, erratic shifting, or difficulty starting the vehicle.

3. What causes the P0603 code to appear on a 2014 GMC Sierra?

Common causes include a weak or disconnected battery, faulty ECM, corroded or loose battery terminals, or issues with wiring or ground connections.

4. Can clearing the P0603 code solve the problem on a 2014 GMC Sierra?

Clearing the code might temporarily turn off the check engine light, but it wonâ€™t fix the underlying issue causing the ECM memory reset.

5. How do I diagnose the P0603 code on my 2014 GMC Sierra?

Start by checking the battery voltage, inspecting battery terminals, and testing the alternator. If no issues are found, examine the ECM wiring and ground connections for damage or corrosion.

6. Is it safe to drive a 2014 GMC Sierra with the P0603 code?

While you might be able to drive the vehicle, itâ€™s not recommended as the ECM could malfunction or lose critical data, potentially leading to poor performance or stalling.

7. Could a weak battery cause the P0603 code on a 2014 GMC Sierra?

Yes, a weak or failing battery can interrupt power to the ECM, causing it to lose stored memory and trigger the P0603 code.

8. How much does it cost to fix the P0603 code on a 2014 GMC Sierra?

The cost varies depending on the cause. Replacing a battery or fixing wiring might cost $100-$300, while replacing the ECM can range from $500 to $1,200.

9. Can a software update fix the P0603 code on a 2014 GMC Sierra?

In some cases, an ECM software update performed by a dealership may resolve the issue if itâ€™s related to a software glitch.

10. When should the ECM be replaced for the P0603 code?

The ECM should only be replaced if all other potential causes, such as battery issues, wiring, or ground faults, have been ruled out and the ECM is confirmed to be faulty.