DTC Code P0703 – What does this code mean?
<p>DTC Code P0703 for Volkswagen vehicles indicates a malfunction in the <b>Brake Switch 'B' Circuit</b>, where a plausibility check between the brake pedal switches and the accelerator pedal position sensor fails. This code is triggered when the engine control module detects an issue with the brake pedal switch configuration, which may involve one normally open and one normally closed switch.</p>
Symptoms for Error Code P0703
<ul>
<li><a href="/problems/vw-check-engine-light-is-on"><b>Engine Light ON</b></a>: The check engine light or service engine soon warning light illuminates, indicating a potential issue with the brake switch 'B' circuit.</li>
<li><b>Brake Lights Inoperative</b>: The brake lights may not function properly, which can be linked to a malfunction in the brake switch 'B' circuit.</li>
</ul>
Common Causes for Error Code P0703
<ul><li>The brake switch may be malfunctioning, leading to incorrect signals being sent to the vehicle's control systems.</li><li>An open or shorted brake switch harness can disrupt the electrical flow, causing the circuit to fail.</li><li>Poor electrical connections in the brake switch circuit can result in intermittent or failed communication with the ECM.</li><li>A faulty Engine Control Module (ECM) can misinterpret or fail to process signals from the brake switch, triggering the error code.</li></ul>
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Troubleshooting for Error Code P0703
<ul>
<li><b>Initial Visual Inspection</b>: Inspect the brake switch and its wiring for any visible damage or disconnection. Ensure the brake pedal is not obstructed and moves freely.</li>
<li><b>Check Brake Lights</b>: Depress the brake pedal and verify if the brake lights illuminate. If they do not, proceed to check the brake switch.</li>
<li><b>Test Brake Switch</b>: Use a multimeter to test the brake switch for continuity. With the brake pedal depressed, the switch should show continuity. If not, the switch may be faulty.</li>
<li><b>Inspect Brake Switch Adjustment</b>: Ensure the brake switch is properly adjusted. It should be positioned so that it activates when the brake pedal is depressed.</li>
<li><b>Check Brake Switch Connector</b>: Inspect the connector for corrosion or loose connections. Clean and secure the connector if necessary.</li>
<li><b>Replace Brake Switch</b>: If the brake switch is faulty or cannot be adjusted properly, replace it with a new one and verify the operation of the brake lights.</li>
<li><b>Clear DTC and Test Drive</b>: Clear the DTC code and perform a test drive to ensure the issue is resolved and the code does not return.</li></ul>
Severity Description for Error Code P0703
<p>The DTC P0703 for Volkswagen indicates an issue with the Brake Switch 'B' Circuit. This is a <b>moderate</b> concern as it can affect the vehicle's braking system and cruise control functionality. If not addressed, it may lead to <ul><li>inconsistent brake light operation</li><li>potential safety risks during driving</li></ul>. Prompt attention is advised to ensure safe vehicle operation.</p>