The answer to this question may seem pretty confusing but its really not. It's quite simple actually. For many years the smog program in California has confused consumers about the types of smog inspections there are. This problem could very easily be fixed by renaming the types of shops, and editing the wording on the DMV paperwork, but its a mystery why they don't. I will explain to you how the smog program is structured so you can fully understand what's going on, even though most of this information is quite useless to the consumer. I will first explain smog areas, the procedures, or if you would like to skip all that you can scroll down to Types of Stations to find the answer to the question above.
Typs of Smog Areas in California
California has split up the state into 3 areas that determine the type of smog you need. Test Only & Regular smog are NOT types of smog checks. They are types of stations. There is a big difference between the type of station and type of smog check. There are three types of smog inspection areas in California:
Enhanced Areas: Vehicles within specified model years are required to be certified every two years during their registration renewal with DMV. Also a portion of the vehicles are required to obtain a certificate (passing Smog test) from a Test-Only or Gold Shield station. Vehicles registered in an Enhanced Area must receive an ASM (Acceleration Simulation Mode) Smog Check unless the vehicle is not compatible.
Basic Areas: Vehicles within specified model years are required to be certified every two years during their registration renewal with DMV. Vehicles registered in a Basic Area must receive a TSI (Two Speed Idle) Smog Check.
Change of Ownership Areas: Vehicles within specified model years are required to be certified only upon change of ownership or initial registration in California. Vehicles registered in this area must receive a TSI (Two Speed Idle) Smog Check.
In a nutshell, the area your vehicle is registered in determines whether your receive a TSI (Two Speed Idle) test or an ASM (Acceleration Simulation Mode) test. As a consumer, this information is useless because it has to do with the shops and the procedures. GOOD TO KNOW BUT USELESS!
Types of Smog Inspection Procedures
There are two ways to get the inspection; TSI ( Two Speed Idle) and ASM (Acceleration Simulation Mode).
TSI (Two Speed Idle): Vehicle is put into Park or Neutral, engine speed is held at 2,500 RPM for 30 seconds, then at idle (under 1,200 RPM) for another 30 seconds. Functional OBD-II computer test for check engine light and fault codes. And a Visual Inspection for defective or modified emissions controls parts.
ASM (Acceleration Simulation Mode): Vehicle is ran on a dynamometer at 15 MPH for up to 90 seconds, then accelerated to 25 MPH for another 90 seconds. Functional OBD-II computer test for check engine light and fault codes. And a Visual Inspection for defective or modified emissions controls parts.
Regardless of the area, All-Wheel-Drive vehicles will recieve a TSI test at any smog station. As a consumer this will only affect pricing in some areas which means this information is GOOD TO KNOW BUT USELESS!
Types of Smog Stations
Now we will answer the big question, WHAT IS THE DIFFERENCE? There are 3 types of stations in California and they ALL can issue certificates but under certain conditions. The DMV directs vehicles to one of these three and this is where the confusion happens.
Test Only Station: These stations can perform the inspection and issue a certificate for any car that passes, BUT they cannot perform ANY type of repairs on the vehicle.
Regular Smog Station: These are also known as Smog & Repair shops. They can perform smog inspections for SOME vehicles and repairs for all vehicles.
Gold Shield Stations: These stations started out as a test and repair, have met a certain level of competency to be licensed to inspect any type of vehicle and repair any type of vehicle. They also provide service for the CAP (Consumer Assistance Program).
*If the DMV sends you to a Test-Only or Gold Shield, this means you have to take your car to either one of those. You CANNOT take it to a Smog & Repair Shop.
**If the DMV sends you to a regular smog station, this means your free to take it to ANY SHOP you'd like.
As a consumer, this bit of information is GOOD TO KNOW, AND VERY IMPORTANT.