AutoCodes – GMC – P1503 GMC

P1503 GMC Code - Theft Deterrent Fuel Enable Signal Not Correct

Quick Answer

With the engine cranking, the Powertrain Control Module (PCM) received a frequency code that did not match the code it received from the theft deterrent module. Common causes include Faulty Theft Deterrent System, Theft Deterrent System program. 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
P1503 GMC indicates Theft Deterrent Fuel Enable Signal Not Correct.
Common causes
Common causes include Faulty Theft Deterrent System, Theft Deterrent System program.
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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 3,752
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Aug 25, 2019
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Code P1503 GMC Description

With the engine cranking, the Powertrain Control Module (PCM) received a frequency code that did not match the code it received from the theft deterrent module.
OBDII Code P1503 GMC - Theft Deterrent Fuel Enable Signal Not Correct - AutoCodes.com
P1503 GMC Code - Theft Deterrent Fuel Enable Signal Not Correct

What are the Possible Causes of the DTC P1503 GMC?

  • Faulty Theft Deterrent System
  • Theft Deterrent System program

How to Fix the DTC P1503 GMC?

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 P1503 GMC 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 P1503 GMC 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 P1503 GMC Code

What does the OBDII code P1503 mean on a GMC vehicle?

The code P1503 indicates a problem with the theft deterrent system, specifically the fuel enable signal not being correct or received by the engine control module (ECM).

What are the common symptoms of code P1503 on a GMC?

Symptoms include the engine failing to start, the security light illuminating on the dashboard, and potentially limited or no fuel delivery to the engine.

What causes code P1503 on a GMC vehicle?

Common causes include a faulty theft deterrent module, damaged wiring or connectors in the fuel enable signal circuit, or a malfunctioning ECM.

How is the P1503 code diagnosed on a GMC?

Technicians typically check for related codes, inspect the theft deterrent module, test the fuel enable signal circuit for continuity, and verify proper communication between the module and ECM.

Can a dead battery trigger code P1503 on a GMC?

Yes, a dead or weak battery can sometimes disrupt the theft deterrent system, causing the P1503 code to appear.

How can code P1503 be fixed on a GMC vehicle?

Repairs may include replacing the theft deterrent module, repairing damaged wiring or connectors, or reprogramming the ECM to ensure proper communication.

Is it safe to drive a GMC vehicle with code P1503?

No, the P1503 code typically prevents the engine from starting, so the vehicle will likely be inoperable until the issue is resolved.

Will clearing the P1503 code fix the problem permanently?

Clearing the code may temporarily remove it, but the underlying issue must be addressed to prevent the code from returning and restore proper vehicle operation.

Can code P1503 be related to a faulty key or key fob on a GMC?

Yes, a malfunctioning or unprogrammed key or key fob can prevent the theft deterrent system from recognizing the correct fuel enable signal, triggering the P1503 code.

How much does it typically cost to repair code P1503 on a GMC?

Repair costs vary depending on the issue but can range from $100 to $600, including parts and labor, depending on whether the theft deterrent module, wiring, or ECM requires replacement.

Discuss the causes and fixes for P1503 GMC OBDII Code

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