Volkswagen DTC P1421 – Secondary Air Injection Valve Circuit Short To Ground
DTC P1421 meaning on Volkswagen
DTC P1421 on a Volkswagen indicates a fault with the Secondary Air Injection (AIR) system. Specifically, it points to a short circuit to ground in the circuit that controls the Secondary Air Injection Valve.
Volkswagen DTC P1421 symptoms
Symptoms of DTC P1421 on a Volkswagen may include:
- Check Engine Light illuminated
- Reduced engine performance
- Increased emissions
- Possible rough idling or stalling
Volkswagen DTC P1421 causes
The common causes of DTC P1421 on a Volkswagen are:
- Short to ground in the Secondary Air Injection Valve circuit
- Faulty Secondary Air Injection Valve
- Wiring issues in the AIR system
Volkswagen DTC P1421 seriousness
While DTC P1421 may not cause immediate drivability issues, it can lead to increased emissions and potential long-term engine problems if left unresolved. It is recommended to address this issue promptly to maintain optimal vehicle performance and emissions compliance.
How to diagnose DTC P1421 on Volkswagen
To diagnose DTC P1421 on a Volkswagen, follow these steps:
- Use a diagnostic scanner to retrieve the fault code
- Inspect the wiring and connectors related to the Secondary Air Injection Valve
- Test the Secondary Air Injection Valve for proper operation
- Check for any visible signs of damage or corrosion in the system
How to fix DTC P1421 on Volkswagen
To fix DTC P1421 on a Volkswagen, you can:
- Repair any damaged wiring or connectors in the Secondary Air Injection Valve circuit
- Replace the faulty Secondary Air Injection Valve if necessary
- Clear the fault code and reset the Check Engine Light
How to erase DTC P1421 on Volkswagen
To erase DTC P1421 on a Volkswagen, you can:
- Use a diagnostic scanner to clear the fault code
- Ensure that the underlying issue causing the fault code has been resolved
- Perform a test drive to confirm that the Check Engine Light does not reappear
Recommended tools for Volkswagen diagnostics
Explore our expert picks: The Best OBD2 Scanners for 2025
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.