AutoCodes – Buick – P0603 Buick

P0603 Buick 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 Buick 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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 3,059

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
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0603 Buick 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 Buick - Control Module Long Term Memory Reset - AutoCodes.com — P0603 Buick Code - Control Module Long Term Memory Reset

What does this mean?

What are the Possible Causes of the DTC P0603 Buick?

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 Buick?

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 Buick 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 Buick code?

Need more information on how to fix the P0603 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0603 Buick code diagnosed by a professional: Find a repair shop in your area

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.