HDIM Testing: HDIM testing involves inspecting and testing the emissions and exhaust systems of heavy-duty trucks to ensure they comply with state and federal regulations. This typically includes checking emissions control devices, exhaust systems, and diagnosing any performance issues that may affect emissions.

Repair Work for Emissions Systems: If a truck fails the emissions test, repairs may be needed. Common repairs could involve replacing or cleaning diesel particulate filters (DPFs), fixing or replacing exhaust gas recirculation (EGR) systems, or addressing other issues that prevent the vehicle from meeting emissions standards.

Reprogramming or Software Updates: Sometimes, trucks require updates to the engine control module (ECM) or the reprogramming of engine settings to pass the emissions tests.

Smog Checks for Heavy Duty Trucks: Unlike passenger vehicles, semi-trucks and large commercial vehicles have their own emissions testing requirements. These tests typically check for pollutants like nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO).

Heavy-Duty Diesel Smog Testing: California has specific rules for smog testing semi-trucks and diesel engines. These tests ensure that trucks with diesel engines are within the emissions limits set by CARB and federal authorities.

Smog Certification: If a truck passes the smog test, it receives a certificate of compliance that allows it to be legally operated on the road in California. If it fails, the owner must perform repairs and then re-test the vehicle.

Emissions Diagnostics: Identifying the source of emissions failures, including checking for faulty sensors, worn-out filters, or other malfunctioning parts.

Repair and Maintenance: Fixing or replacing components like the DPF, EGR valves, and other parts that are critical to a truck’s emissions system.

Software Calibration/ECM Updates: Updating or reprogramming the truck’s engine control system to comply with emissions standards.

Fleet Compliance: Helping fleets manage emissions compliance, ensuring that all trucks in a fleet meet the latest standards, and keeping track of when each vehicle needs testing or repair.