C2021 Subaru Code - Tire 1 Air Pressure Decrease
Quick Answer
The Tire Pressure Monitor (TPM) system checks the tire pressures of all 4 road wheels when the vehicle is driven at speeds above 25 mph (40 km/h), and warns in the event of a loss of pressure by means of a low tire pressure warning light. Common causes include Tire pressure not to factory specifications, Faulty Tire Pressure Transmitter, Faulty Tire Pressure Monitor System (TPMS) Control Module. 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
- C2021 Subaru indicates Tire 1 Air Pressure Decrease.
- Common causes
- Common causes include Tire pressure not to factory specifications, Faulty Tire Pressure Transmitter, Faulty Tire Pressure Monitor System (TPMS) Control Module.
- 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.
Code C2021 Subaru Description
What are the Possible Causes of the DTC C2021 Subaru?
- Tire pressure not to factory specifications
- Faulty Tire Pressure Transmitter
- Faulty Tire Pressure Monitor System (TPMS) Control Module
How to Fix the DTC C2021 Subaru?
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.
Code Tech Notes
If the warning light is still on after adjusting tire pressure, check for a damaged tire and repair as necessary. If warning light blinks 25 times and then illuminates, and there is not a tire without a tire pressure sensor installed, there is a malfunction in the TPM system. See appropriate manufacturer service information.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the C2021 Subaru 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.
Need more information about the C2021 Subaru code?
Need more information on how to fix the C2021 Subaru code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the C2021 Subaru code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about C2021 Subaru Code
1. What are the common symptoms of OBDII code C2021 in a Subaru related to Tire 1 Air Pressure Decrease?
- The common symptoms include a warning light on the dashboard indicating low tire pressure in the first tire (Tire 1) and potential handling issues while driving.
2. What are the possible causes of OBDII code C2021 in a Subaru indicating Tire 1 Air Pressure Decrease?
- The code C2021 typically points to a fault with the tire pressure monitoring system (TPMS) sensor in Tire 1, such as a sensor malfunction, low battery, or signal interference.
3. How can I diagnose the issue causing OBDII code C2021 in my Subaru related to Tire 1 Air Pressure Decrease?
- To diagnose the problem, you can start by checking the tire pressure in Tire 1 manually, inspecting the TPMS sensor for damage, and using an OBDII scanner to read the specific error codes.
4. Can low tire pressure in Tire 1 trigger OBDII code C2021 in a Subaru?
- Yes, low tire pressure in Tire 1 can trigger the code C2021, as the TPMS sensor is designed to alert the driver when there is a significant decrease in air pressure in a specific tire.
5. What are some repair tips for resolving OBDII code C2021 in a Subaru related to Tire 1 Air Pressure Decrease?
- Repair tips may include checking and adjusting the tire pressure in Tire 1, replacing the TPMS sensor in that tire if necessary, resetting the TPMS system, and ensuring proper sensor calibration.
6. Is it safe to continue driving with OBDII code C2021 indicating Tire 1 Air Pressure Decrease in a Subaru?
- It is not recommended to drive with the code C2021 active, as it can affect the vehicle's handling and compromise safety by potentially leading to tire-related issues.
7. How do I reset the TPMS system after resolving OBDII code C2021 in a Subaru related to Tire 1 Air Pressure Decrease?
- The TPMS system can typically be reset by following the manufacturer's instructions, which may involve driving the vehicle at a certain speed for a specific duration or using a reset button inside the car.
8. Can extreme weather conditions affect the triggering of OBDII code C2021 related to Tire 1 Air Pressure Decrease in a Subaru?
- Yes, extreme cold or hot weather can affect tire pressure and trigger the TPMS system to alert for low air pressure, potentially leading to the activation of code C2021.
9. Do I need to visit a dealership for service if OBDII code C2021 appears in my Subaru indicating Tire 1 Air Pressure Decrease?
- While visiting a dealership for specialized service is recommended, you can also address the issue at a trusted automotive repair shop or by following the manufacturer's guidelines for troubleshooting and repair.
10. How often should I check the tire pressure in my Subaru to prevent OBDII code C2021 related to Tire 1 Air Pressure Decrease?
- It is advisable to check the tire pressure regularly, at least once a month or before long trips, to maintain proper inflation levels and prevent issues that could trigger the TPMS system and OBDII code C2021.
Discuss the causes and fixes for C2021 Subaru OBDII Code
Code C2021 Subaru comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
