OBD II diagnostic interface
 

Which cheap diagnostic interface for Chevy Blazer 1998?

Not sure what you're asking? Are you asking what will read codes? Any OBD2 compliant scan tool will read codes from that truck, including the Bluetooth and wifi modules you can pair with your phone. I have a Bluetooth one that I use and it works great. I would suggest doing a bit of research to make sure you get one that meets your needs.

Good phone apps:

• All require Bluetooth for Android or Wifi for iPhone - OBD2 adapter - suggest BAFX Bluetooth OBD2 adapter as sold on Amazon ($22) and your should get around 30 data reads/sec with it. Others as low as 3 reads/sec (first one that I had, cost only $12).
• Car Gauge Pro 1998+ Blazers for Android ($8.95) (comes with enhanced powertrain PIDs). Also reads/clears SIR, ABS, TCCM, BCM etc. codes. Most difficult to use. Does the most on our Blazers, but PIDs and modules are unfiltered - many don't work for Blazers but you will still see them in the app. Need to be familiar with what you are doing with this app and exactly what it is capable of.
• Dash Comand 1996+ Blazers for Android or iPhone ($10 + $10 for enhanced powertrain PIDs for each vehicle you want them for) - Just works with power-train items - nicely done app - works for enhanced PIDs on the early PCM. Works for enhanced PIDs on later vehicles as well. Only Bluetooth app I have that can do the enhanced PIDs on my 1996 Pontiac G6 with first year of CAN protocol.
• Torque Pro for Android (no cam sensor retard PID on Blazers) ($4.95) don't know if it will do anything enhanced for 1996-97 Blazers (it does come with enhanced PIDs and enhanced powertrain PIDs will work for sure on 1998+). Just works with powertrain codes. The most popular phone app out there. Very nice looking user interface. Won't connect to my G6 at all, even for basic non-enhanced OBD2 functions like reading codes.

I have all three. They each have their use! None is perfect, and none does everything that the others do. But they are always there to easily use if you keep the OBD2 adapter in the vehicle.

Also have Scan XL Pro with GM Enhanced PIDS for Windows - $150 + USB OBD2 adapter - light speed in comparison to Bluetooth but Car Gauge Pro does more functionally. Supposed to do ABS, but I have not verified. Seldom use it anymore. Was my first software after Torque Pro, bought to do cam sensor retard. Needs a laptop.

Also have HP Tuners VCM scanner for Windows with GM package - $350 has it's own OBD2 adapter - does crank sensor relearn, injector balance testing, transmission control, fan control, solenoid control, other bidirectional control. Only use it when I need more than Car Gauge Pro. Needs a laptop.

I have an ELM 327 Bluetooth OBD2 mini interface. I use Torque, Piston, Obd Army, EOBD Facile, DashCommand. Unfortunately, no application connects to my car. I checked with other European cars and the sale is OK. That's why I am looking for an affordable interface with 100% certainty that it will connect to my car. I want to read and remove the ECU error. I will be happy if it can be combined with the gearbox. What do you recommend?

If your interface works on another vehicle, then check your vehicle for power and ground per the image below. Sounds like the problem is with your vehicle, not the application/interface.
http://www.onboarddiagnostics.com/images/j1962pwm.gif (note this image is incorrect for Blazer see post #8)
Dash Command will definitely read Powertrain (engine and transmission) codes on a 1998 Blazer, as will Torque Pro. If you are using pirated copies of these programs, that could also be a possible issue.

Good luck and best wishes. Let us know the result.

In my car are available pins 2,4,5, and 9,13,16. Pin number 10 is empty. Are you sure that OBD II connector from this photo concerns my car? Chevy Blazer LT 4.3 V6 4WD 1998y.

Any suggestions?

Sorry, you have J1850-VPW. The one I gave you previously by mistake was the original Ford protocol (J1850-PWM).

Here are the mandatory wire pinouts for the various OBD2 protocols that were used (can be additional pins present but these wires are mandatory for the protocol to work). Still need to check for 12V and ground on the correct pins. Do you have a test light or a multimeter?

OnBoardDiagnostics.com - OBD-II Network Standards

I checked. There is power. Today I ordered "BAFX Products® Bluetooth OBD2 reader". He will reach me in about 6-8 weeks. I hope he will connect with my car.

That one is known to work well. I still wonder if the problem is with the vehicle since your current adapter reads on other vehicles. Good luck! Keep us posted.