AutoCodes – GMC – P0603 2016 GMC Sierra

P0603 2016 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 2016 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 270

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 2016 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 2016 GMC Sierra - Control Module Long Term Memory Reset - AutoCodes.com — P0603 2016 GMC Sierra Code - Control Module Long Term Memory Reset

What does this mean?

What are the Possible Causes of the DTC P0603 2016 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 2016 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 2016 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 2016 GMC Sierra code?

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Need Help with the 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 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 PCMâ€™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 isnâ€™t resolved.

8. Can clearing the P0603 code solve the problem?

Clearing the code may work temporarily, but if the cause isnâ€™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 PCMâ€™s memory and trigger the P0603 code.