3 button and 4 button transfer cases are not interchangeable, so the wrong one will do you no good. PCM calibration and vehicle wiring are different.

 

As of yesterday I discovered that one of my inexpensive android OBD2 apps apparently reads TCCM codes (and many other system codes too).

I do not have a 4x4 problem to evaluate right now, but I can say that Car Gauge Pro does read HVAC codes (at least it does on my 2004 Avalanche). This implies that it can read codes for other modules on the data bus (like the TCCM). I see no reason for a 2001 Blazer to be different.

Yesterday I noticed that the TCCM was specifically included in the list of modules where codes were checked when doing a specific "Scan all faults". With no problems in this area, of course mine showed no codes there. But since it did read a couple of HVAC codes this way, I believe Car Gauge Pro is probably capable of reading and clearing TCCM, SIR, ABS, HVAC, BCM, PCM, etc codes.

If you would like to try it on your 4WD system, I will help - but I give no guarantees at this point. You will need the BAFX Bluetooth OBD2 adapter as sold on Amazon for about $22, and the Car Gauge Pro app from Google Play at $5.95.

Another way is to communicate with the TCCM is using a text terminal and typing in the hieroglyphics. I have outlined the procedure in this thread https://blazerforum.com/forum/2nd-ge...-blazer-89044/ and I actually used it on my own vehicle so I know that it works. Scan XL Pro is $150 and OBDlink SX OBD2 adapter is about $30.

Again, all of this depends on your vehicle being a 4-button 4WD with the Auto button.

Let me know.

 

Thank you I've never posted on a forum before so will take some figuring out but it's a 2000 chevy blazer LT 4 button I'm very mechanically inclined I'm just little new to what some of the stuff is called that controls this 4wd

 

I have a problem in the front differential I think when I give it gas it makes some noise but when I'm standing revving it doesn't do anything does anyone know any solutions

 

I have a Iphone ..They don't have that app so I ordered the ELM327 WIFI Wireless ELM327 OBD2 OBDII Auto Diagnostic Scanner Tool Adapter for Smartphone / PC / iOS / iPhone/ iPad/ iTouch /Mac .. and got a app also .. I never knew you could use a smartphone as a scan tool .. pretty awesome info there Lesmyer ! Thank you !

 

You are welcome, but I'm sorry to hear you are an iPhone user wanting to do OBD2 diagnostics. Other than Dash Command I have never heard of an iPhone OBD2 app that is worth even having. But Palmer Performance does happen to make an iPhone version of Dash Command in addition to the Android version.

I really don't think than any phone app other than Car Gauge Pro for Android has a chance of reading TCCM codes (and I'm not yet 100% sure about Car Gauge Pro).

Finally, I don't believe you have ever specified if you have 3-button or 4-button Auto 4WD. 3-button diagnostics is done by jumpering a terminal. 4-button diagnostics is done with a capable scanner.

So if you want to use an iPhone to do anything more than read and clear codes (why bother with that), get Dash Command + the GM PIDS for 1998. That will cost you $10 + $10 more for the 1998 GM Enhanced PIDs. At least you can look at enough live data that it becomes useful for diagnosis of powertrain things (even if it doesn't help with 4WD).

 

It is a 4 button .. I got the app Eobd - facile .. It has a lot of options ..not sure about TCCM but we will see I guess . I also found a stranger problem with the 4wd . We had a "blizzard" or so they said and I pushed the 4 lo button and the light flashed for several seconds then they all went out but the truck went into 4 hi . The roads have been cleared so I tried unhooking the battery and it was still in 4 hi .. I pulled the 4wd fuse for about 10 mins and it disengaged and the 2 hi light is now back on . Also I have had a rattling sound in the passenger front end only between 35 - 45 mph .. Everything is new .. Half shafts , hubs, ball joints , sway bar bushings and links.. It originally sounded like something rattling inside the fender or something but when it went into 4 hi the noise was gone. Back in 2 wheel the noise is back.. Something in the front differential shot ?

 

Rattling in the fender ? passenger side ?,,,,there is a vacuum actuator under the battery , EOBD Facile does have a terminal built in ....you may be able to read the codes that way.

 

To OP. If you can use your EOBD Facile to communicate in a proper terminal mode, what you enter to check, interpret, and clear codes is at the end of this thread.


https://blazerforum.com/forum/2nd-ge...-blazer-89044/

 

The actuator is good and not loose and it is pulling the cable .. The rattle sound really does sound like something bouncing around under the hood but I can only hear it around 35-45 mph .. I have pulled everything off the passenger inner fender well .. from the blower motor to the headlight .. put everything back in , made sure it was all tight .. still there.. Now after this last snow when the truck actually went into 4 hi by pressing 4 lo the noise stopped .. Until I got it back in 2 wheel . The noise came back .. That is why I'm thinking in the front differential or TC . I have a new encoder that I am putting on in the morning so I will see if that fixes the 4wd problem .. Then I will be able to pinpoint the problem a little better when I can get it in and out of 4wd.