I have the SRS dummy light on, so I can’t pass inspection in MA. I am thinking it probably is the passenger seat weight sensor for the air bag in my 2006 Ford Focus, but I want to be sure before I take the seat apart. So, I went to Autozone to see if they can read the code for me. They do have a scanner, but it only reads DTC codes. Thinking this may be a good excuse to buy another tool, I am looking around for a scanner. I have the absolute basic scan tool that sells for less than $20 on Amazon. It only reads DTC codes and erases them. But the models that can read ABS and SRS do all kinds of fancy stuff. I am not picky about a particular brand, but the models that seem to be popular on Amazon are Innova 3150 ($110) and Innova 3160 ($170). Only difference between them is that 3160 does OBD2 Live stream display, OBD2 all modes 1-10; Bi-directional control Service mode 8 - EVAP; Record graph and playback live data on screen. What are these three functions? Please make suggestions on other models I should consider. Thank you for your reply.
The Innova is a good brand. Buy the best one you can afford. Actron is another good brand.
You spent $20 and now you’re back at the trough 
My advice is not to scrimp now over $60.
At some point, you may want/need those additional features and then you’ll be back at the trough again but having far more invested and still come up short.
The fact you say it’s a good opportunity to buy another tool tells me it isn’t likely to break the bank but you just don’t want to spend money for features you’ll maybe never use. In that case, see above.
I own the Innova 3160. It cost far less than one trip to the shop. I haven’t used all of the features but they’re there if I do need them. And if history is any guide, having them is just insurance against needing them (like buying a new plow and it doesn’t snow for the next couple of years).
I have the Innova model and like it a lot. You might also like the models from Actron. Whatever you get, I do suggest you get one with the live data feature. You can justify the extra cost of the top model with the first repair job that you use the extra features to help find the trouble.
I don’t think you will be able to diagnose and repair the passenger seat Occupant Classification System with these basic scan tools.
There could be a simple fault like a clockspring failure but if the problem is in the OCS the Airbag module will usually display a fault like “Fault present in OCS module”, you will need a better scan tool to access that module.
I don’t see a service or utilities selection on the Innova 3160, I don’t know how you will be able to perform the passenger seat calibration to correct the problem or verify failure. There is a “Live data” button but it appears to only display PCM data, is there a way to select the ABS or airbag module for live data?
The passenger seat bottom w/bladder, sensor and module will be expensive, you will want to perform a thorough diagnosis. Most OCS faults are due to loss of calibration.
Can you recommend the cheapest option for Tool for calibrating the OCS