AutoCodes – Volkswagen – P1603 Volkswagen

P1603 Volkswagen Code - Engine Control Module Defective

Quick Answer

Battery positive voltage is supplied to the Engine Control Module (ECM) even when the ignition switch is OFF for use by the Diagnostic Trouble Code (DTC) memory and air–fuel ratio adaptive control value memory, etc. Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) 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: P1603 Volkswagen indicates Engine Control Module Defective.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) 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 29,182

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 May 20, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1603 Volkswagen Description

OBDII Code P1603 Volkswagen - Engine Control Module Defective - AutoCodes.com — P1603 Volkswagen Code - Engine Control Module Defective

What does this mean?

What are the Possible Causes of the DTC P1603 Volkswagen?

Faulty Engine Control Module (ECM)
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical connection

How to Fix the DTC P1603 Volkswagen?

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 P1603 Volkswagen 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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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 P1603 Volkswagen Code

1. What does the OBDII code P1603 mean on a Volkswagen?

P1603 indicates a potential defect in the Engine Control Module (ECM), suggesting issues with its internal operation or communication.

2. What are common symptoms of the P1603 code in a Volkswagen?

Symptoms may include difficulty starting the engine, stalling, poor engine performance, reduced fuel efficiency, and the check engine light illuminating.

3. What causes the P1603 code on a Volkswagen?

Common causes include a failing ECM, damaged wiring or connectors, power supply issues to the ECM, or software corruption.

4. Can a weak battery trigger the P1603 code in a Volkswagen?

Yes, a weak or failing battery can cause voltage irregularities that may lead to ECM malfunctions and trigger the P1603 code.

5. How do I diagnose the P1603 code on my Volkswagen?

Diagnosis involves checking the battery and power supply to the ECM, inspecting wiring and connectors, scanning for additional codes, and testing the ECM itself.

6. Can the P1603 code be fixed without replacing the ECM?

In some cases, the code can be resolved by repairing wiring issues, replacing the battery, or updating the ECM software, but severe faults may require ECM replacement.

7. How much does it cost to fix the P1603 code on a Volkswagen?

The cost depends on the root cause. Minor repairs like wiring fixes or battery replacement may cost $100-$300, while ECM replacement can range from $500 to $1,500 or more.

8. Can driving with the P1603 code damage the engine?

Driving with this code can lead to erratic engine behavior, which may cause further damage to engine components over time if not addressed promptly.

9. Does clearing the P1603 code solve the problem?

Clearing the code may temporarily turn off the check engine light, but the underlying issue must be resolved to prevent the code from returning.

10. Should I replace the ECM immediately if I get a P1603 code?

Not necessarily. Perform a thorough diagnosis first, as the issue could stem from external factors like wiring or power supply problems rather than a defective ECM.