AutoCodes – Chevrolet – P1003 2018 Chevrolet Silverado

P1003 2018 Chevrolet Silverado Code - Fuel Composition Signals Message Counter Incorrect

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty Fuel Composition Sensor, Fuel Composition Sensor harness is open or shorted, Fuel Composition Sensor circuit poor electrical 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: P1003 2018 Chevrolet Silverado indicates Fuel Composition Signals Message Counter Incorrect.
Common causes: Common causes include Faulty Fuel Composition Sensor, Fuel Composition Sensor harness is open or shorted, Fuel Composition Sensor circuit poor electrical 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.

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Code Popularity 305

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 Aug 18, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1003 2018 Chevrolet Silverado Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the Fuel Composition Signals Message Counter Incorrect.

OBDII Code P1003 2018 Chevrolet Silverado - Fuel Composition Signals Message Counter Incorrect - AutoCodes.com — P1003 2018 Chevrolet Silverado Code - Fuel Composition Signals Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P1003 2018 Chevrolet Silverado?

Faulty Fuel Composition Sensor
Fuel Composition Sensor harness is open or shorted
Fuel Composition Sensor circuit poor electrical connection

How to Fix the DTC P1003 2018 Chevrolet Silverado?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1003 2018 Chevrolet Silverado 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 P1003 2018 Chevrolet Silverado code?

Need more information on how to fix the P1003 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 P1003 2018 Chevrolet Silverado Code

1. What does the OBDII code P1003 mean on a 2018 Chevrolet Silverado?

P1003 indicates an issue with the fuel composition signal message counter, meaning the engine control module (ECM) is receiving incorrect or inconsistent data about the fuel's ethanol content.

2. What are the common symptoms of code P1003 in a 2018 Chevrolet Silverado?

Symptoms may include poor engine performance, reduced fuel efficiency, difficulty starting, or an illuminated check engine light.

3. What causes the P1003 code to appear on a Chevrolet Silverado?

Common causes include a faulty fuel composition sensor, wiring or connector issues, a malfunctioning ECM, or the use of contaminated or incorrect fuel.

4. Can bad fuel cause the P1003 code on a 2018 Chevrolet Silverado?

Yes, using fuel with excessive water, debris, or incorrect ethanol content can cause the fuel composition sensor to send inaccurate signals, triggering this code.

5. How do I diagnose the P1003 code on my Chevrolet Silverado?

Start by inspecting the fuel composition sensor, its wiring, and connectors for damage or corrosion. Use a scan tool to monitor fuel composition data and check for related trouble codes.

6. Can I drive my 2018 Chevrolet Silverado with the P1003 code?

While the vehicle may still be drivable, it could experience performance issues, and prolonged driving with this code may lead to further engine damage or reduced efficiency.

7. How is the P1003 code repaired on a Chevrolet Silverado?

Repairs may include replacing the fuel composition sensor, repairing or replacing damaged wiring or connectors, and in rare cases, reprogramming or replacing the ECM.

8. How much does it cost to fix the P1003 code on a 2018 Chevrolet Silverado?

Costs can vary but typically range from $150 to $500, depending on whether the issue is with the sensor, wiring, or ECM.

9. Can a software update fix the P1003 code on a Chevrolet Silverado?

In some cases, a software update for the ECM may resolve the issue if the problem is related to incorrect signal interpretation rather than hardware failure.

10. How can I prevent the P1003 code from occurring again?

Regularly use high-quality fuel, perform routine maintenance, and inspect the fuel system components periodically to catch potential issues early.