Hi everyone , im from Ecuador and have a blazer s10 1998 4x2 and couples mounth before i've been robed my ecm then i buy one her in my country but the electromecanic said me that ecm is for my car but with the transmission mecanic and my blazer have a automatic transsmision soo exist other solution or just buy other ecm ? pls help


my problem is that ecm my blazer turn on and road but dont know change of speed and doesnt work a speedometeer

 

Let me make sure I understand.

You had your ecm replaced with one from a manual transmission blazer. Now your speedometer doesn't work. Is that correct?

When an ecm is changed, it should be "reflashed" (reprogramed) to match all the features of the vehicle it is going in.

Any chevrolet dealership should be able to do that for you.


Out of curiosity: does your truck shift gears?

 

yes i know but doesnt work and doesnt shift gears only to second gear

 

Correctly and doesnt shift gears only to second gear is like the ecm doesnt know the transmission , and my transmission is new

 

And what he said is you have to go to a Chevrolet dealer and have your ECM reprogrammed. Thats the only thing you can do

 

ok , thanks but exist the tutorial how reprogramme the ecm and is that with the key and the swith key close and open with specific time or is the other reprogramm?

 

Reprogramming of the PCM needs to be performed with a compatible scantool (GM Tech2 or equivalent) with access to GM TIS/SPS system to get the specific programming for your VIN (vehicle identification number).

 

The reprogram you describe is for security system only, once PCM is installed in vehicle.

We have services here in the USA that will sell used PCM with correct programming for your vehicle. But they must have your VIN number so they can do programming before it is sent. Person who sold used PCM to you should have known this. If you don't have a local service that can do the programming in the vehicle, maybe you can ship your same PCM and give VIN to someone who can program it correctly for you to install.

But first you may want to check a few things. Your symptoms with transmission shifting and speedometer fit problems with VSS (Vehicle speed sensor) or a fuse being blown. Are there any codes being set? Is the Service Engine Soon or any other warning light on?

 

Being that the pcm is from a manual transmission vehicle, it wouldnt be looking for the vss signal or sending signal to the tcm in the first place. All the symptoms point to vss, but only because the pcm isn't doing anything with the vss signal.

You're absolutely right though, the person who did the pcm should have known it would need to be reflashed.

 

thanks so much for the information and no any light or warning code but in the scanner show that the solenoids no working with the time soo that is problem the ecm