DTC Code P202A – What does this code mean?

<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 reductant tank heater control circuit.</li> <li><b>Poor Emission Control</b>: The vehicle may experience reduced efficiency in emission control, potentially leading to increased emissions due to the malfunctioning reductant tank heater.</li> <li><b>Cold Weather Performance Issues</b>: In colder climates, the reductant tank heater may fail to operate, leading to potential freezing of the reductant fluid, affecting the vehicle's performance.</li> </ul>

<ul><li>The reductant tank heater may be faulty, leading to improper heating of the DEF fluid, which can affect emissions control.</li><li>An open or shorted harness in the reductant tank heater can disrupt the electrical flow, causing the system to malfunction.</li><li>Poor electrical connections in the reductant tank heater circuit can result in intermittent or no power supply, affecting the heater's operation.</li></ul>

<ul> <li><b>Initial Inspection</b>: Visually inspect the reductant tank heater wiring and connectors for any signs of damage, corrosion, or disconnection.</li> <li><b>Check Power Supply</b>: Verify that the reductant tank heater is receiving power by checking the voltage at the heater connector with a multimeter. Ensure the ignition is on during this test.</li> <li><b>Inspect Ground Connection</b>: Ensure the ground connection for the reductant tank heater is secure and free of corrosion. Use a multimeter to check for continuity between the heater ground and the vehicle chassis.</li> <li><b>Test Heater Resistance</b>: Measure the resistance of the reductant tank heater using a multimeter. Compare the reading to the manufacturer's specifications to determine if the heater is functioning correctly.</li> <li><b>Examine Control Circuit</b>: Inspect the control circuit for the reductant tank heater. Check for any open or short circuits using a wiring diagram and a multimeter.</li> <li><b>ECU Diagnostic</b>: Perform a diagnostic scan of the Engine Control Unit (ECU) to check for any additional codes or issues that may be affecting the reductant tank heater control circuit.</li></ul>

<p>The DTC P202A for Volkswagen indicates an issue with the <b>Reductant Tank Heater Control Circuit/Open</b>. This is a <b>moderate</b> concern as it affects the vehicle's ability to properly manage the diesel exhaust fluid (DEF) system, especially in cold conditions. If not addressed, it can lead to <ul><li>increased emissions</li><li>potential DEF system malfunction</li></ul>, impacting vehicle performance and compliance with emission standards.</p>