Detailed Description of Error C0077

OBDII error code C0077, also known as ''Low Tire Pressure (Subfault)'', is a fault code that is triggered when the vehicle''s onboard computer, or Engine Control Module (ECM), detects a problem with the tire pressure monitoring system (TPMS). This system is designed to monitor the air pressure in each tire and alert the driver if any tire is underinflated.

The TPMS system consists of sensors mounted on each wheel, which transmit data to the ECM. If the ECM detects a problem with the TPMS system, such as low tire pressure, it will trigger error code C0077 and illuminate the ''Service Tire Pressure System'' or ''Check TPMS System'' warning light on the dashboard.

Error code C0077 is considered a subfault, which means it is a secondary fault that is related to a primary fault in the TPMS system. This means that there may be another underlying issue that is causing the low tire pressure problem.

Possible Causes of Error C0077

• Low tire pressure in one or more tires
• TPMS sensor battery is dead or weak
• TPMS sensor is faulty or damaged
• TPMS module is faulty or damaged
• Wheel speed sensor is faulty or damaged
• ECM or TPMS system software is outdated or corrupted
• Vehicle has been driven in extreme temperatures
• TPMS system has not been properly relearned after tire rotation or replacement

Possible Fixes for Error C0077

1. Check tire pressure and inflate to recommended levels
2. Inspect TPMS sensors for damage or corrosion and replace if necessary
3. Replace TPMS sensor battery if weak or dead
4. Update ECM or TPMS system software if outdated or corrupted
5. Perform TPMS system relearn procedure if necessary
6. Check wheel speed sensor for damage or corrosion and replace if necessary
7. Clear error code and test vehicle to ensure problem is resolved