P202B Code - Reductant Tank Heater Control Circuit Low
Quick Answer
The diagnostic trouble code P202B indicates an issue with the reductant tank heater control circuit being low. Common causes include Faulty Reductant Tank Heater: The reductant tank heater itself may be malfunctioning, causing the control circuit to operate at a lower voltage, Wiring Issues: Damage or corrosion in the wiring harness connected to the reductant tank heater can lead to a low voltage condition, Defective Control Module: A faulty control module responsible for regulating the reductant tank heater may trigger the P202B code. 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
- P202B indicates Reductant Tank Heater Control Circuit Low.
- Common causes
- Common causes include Faulty Reductant Tank Heater: The reductant tank heater itself may be malfunctioning, causing the control circuit to operate at a lower voltage, Wiring Issues: Damage or corrosion in the wiring harness connected to the reductant tank heater can lead to a low voltage condition, Defective Control Module: A faulty control module responsible for regulating the reductant tank heater may trigger the P202B code.
- 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 P202B Description
The diagnostic trouble code P202B indicates an issue with the reductant tank heater control circuit being low. In vehicles equipped with a Selective Catalytic Reduction (SCR) system, the reductant tank heater is responsible for ensuring the diesel exhaust fluid (DEF) remains at the optimal temperature for proper operation of the SCR system. The SCR system uses DEF to reduce harmful emissions by converting nitrogen oxides into harmless nitrogen and water vapor.
Common Causes of P202B
- Faulty Reductant Tank Heater: The reductant tank heater itself may be malfunctioning, causing the control circuit to operate at a lower voltage.
- Wiring Issues: Damage or corrosion in the wiring harness connected to the reductant tank heater can lead to a low voltage condition.
- Defective Control Module: A faulty control module responsible for regulating the reductant tank heater may trigger the P202B code.
- Electrical Short: An electrical short in the circuit controlling the reductant tank heater can cause the voltage to drop below the expected range.
Symptoms of P202B
- Check Engine Light: The most common symptom associated with the P202B code is the illumination of the Check Engine Light on the vehicle's dashboard.
- Reduced Fuel Efficiency: The vehicle may experience reduced fuel efficiency due to improper operation of the SCR system.
- Poor Performance: The vehicle may exhibit poor acceleration and overall performance as a result of the malfunctioning reductant tank heater.
- Failed Emissions Test: If the issue is not resolved, the vehicle may fail emissions testing due to increased emissions.
How to Fix P202B
- Diagnose the Issue: Use a diagnostic scanner to retrieve the trouble codes and perform a thorough inspection of the reductant tank heater system.
- Test the Heater: Check the reductant tank heater's resistance and voltage to determine if it is functioning correctly.
- Inspect Wiring: Inspect the wiring harness for any damage, corrosion, or loose connections that may be affecting the heater's operation.
- Replace Components: Replace any faulty components such as the reductant tank heater, control module, or wiring harness as needed.
- Clear Codes: After completing the repairs, clear the trouble codes and test the vehicle to ensure the issue has been resolved.
Cost to Fix P202B
The typical repair costs for addressing the P202B code can vary depending on the extent of the issue and the specific components that require replacement. In general, the cost of replacing a faulty reductant tank heater, control module, or wiring harness can range from $200 to $800, including parts and labor. Additional diagnostic fees may apply, and it is recommended to consult with a qualified mechanic or repair shop for an accurate estimate based on the vehicle make and model. Keep in mind that labor rates at auto repair shops can vary, with hourly rates typically ranging between $80 and $150.
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Code P202B Information for Specific Makes
- P202B Audi — Reductant Tank Heater Control Circuit Low
- P202B Ford — Reductant Tank Heater Control Circuit Low
- P202B Volkswagen — Reductant Tank Heater Control Circuit Low
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