P0603 2018 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 2018 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.
Code P0603 2018 GMC Sierra Description
What are the Possible Causes of the DTC P0603 2018 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 2018 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0603 2018 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.
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Frequently Asked Questions about P0603 2018 GMC Sierra Code
1. What does the OBD-II code P0603 mean on a 2018 GMC Sierra?
P0603 refers to a "Control Module Long Term Memory Reset," indicating that the Engine Control Module (ECM) has detected a loss of stored memory or configuration data.
2. What are the common symptoms of a P0603 code on a 2018 GMC Sierra?
Symptoms may include an illuminated check engine light, difficulty starting the engine, reduced fuel efficiency, or erratic transmission or engine performance.
3. What causes the P0603 code on a 2018 GMC Sierra?
Common causes include a weak or disconnected battery, faulty ECM, poor electrical connections, or aftermarket tuning/programming of the ECM.
4. Can a weak battery trigger the P0603 code on a GMC Sierra?
Yes, a weak or failing battery can cause voltage fluctuations that may lead to the loss of ECM memory, triggering the P0603 code.
5. How do I fix the P0603 code on my 2018 GMC Sierra?
Start by checking the battery and charging system, inspecting ECM connections for corrosion or damage, and verifying that no aftermarket programming is causing the issue. Replace or reprogram the ECM if necessary.
6. Can aftermarket tuning cause the P0603 code on a 2018 GMC Sierra?
Yes, aftermarket tuning or modifications to the ECM software can interfere with proper memory retention and trigger the P0603 code.
7. Is it safe to drive with a P0603 code on a 2018 GMC Sierra?
It is generally safe to drive short distances, but ignoring the code can lead to further issues like poor performance or starting problems. It’s best to address the code promptly.
8. How can I prevent the P0603 code from recurring on my GMC Sierra?
Ensure the battery and charging system are in good condition, avoid frequent disconnections of the battery, and use only authorized ECM programming.
9. Will clearing the code with a scanner fix the P0603 issue on a 2018 GMC Sierra?
Clearing the code may temporarily remove the warning, but the underlying issue must be addressed to prevent the code from returning.
10. How much does it cost to fix a P0603 code on a 2018 GMC Sierra?
The cost depends on the cause. Battery replacement costs around $100-$300, while ECM replacement or reprogramming can cost $500-$1,500.
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