I just bought a Blazer 4x4 9/15/2020 she ran great till coming home from work acted up check engine light was on so i was like lets get it scanned went to autozone and it just said error. So i went to a friends house that had a scanner thinking my autozone sucks and it probably broken tried again and same thing. Checked fuses looked good so i decide to unplug the battery for a bit and try again came back 20 mins later plug it up and it starts beeping Interior and hazard lights blink for a minute or two when I first get in but truck will do nothing to attempt to start. Keys don't get locked in the column. I tried looking up the answer but have gotten nowhere and i need it for work.

 

There are many possibilities for your issues, some simple (battery voltage, fuses, ...), some complicated (Class 2/J1850 bus problems, ECM failure, ...). Lets start simple:

1) How was the truck running when the CEL came on?

2) Was the truck running OK when you got a communication error with the ODBII port?

3) What do you mean by "keys don't get locked in the column"?

4) What is the voltage measured at the battery with a multimeter? What do the battery connections look like?

5) Inspect the ODBII port under the dash and make sure that it is clean and the sockets are not corroded.

6) What fuses did you check?

Lets see where this gets us and we will go from there.


George

 

It's not a '95, is it?

 

yes its a 1995

 

I found a after market alarm system I removed it now it starts but the check engine lights on but still not luck scanning it so I'm pretty sure i got a bad ECM. Does anyone know if i pull one from the same year will i have to have it reprogrammed.

 

Good call Tom.

The 1995 model year was transitional. Some trucks use ODB I, some use ODBII but the majority use what called ODB 1.5 around here which has the modern ODBII 16 pin connector but not the modern fully compliant ODBII communication protocol and most inexpensive code reader cannot read the data. This may be your issue.


George

 

I wouldn't jump to an ECM yet......just saying...Jerry

 

Ok . How do i get it scanned because im clueless at this point

 

First you need to know what type of system that you have. There are three different systems in a 95. The first system, the computer is located behind the dash and is interfaced using an 12 pin OBD I assembly line data link connector. This system is completely OBD I and codes can be retrieved by jumping the pins. The second system, the computer is located behind the dash, and is interfaced with a 16 pin OBD II style Diagnostic Link Connector. This system is OBD "1.5", and requires a special scanner to retrieve the codes. The third system has the computer located on the passenger side fender, above the coolant reservoir, and uses a 16 pin OBD II style connector. This system is OBD II, and codes can be retrieved with a generic OBD II scanner. I have seen comments that these rules may not be 100% accurate for every truck.

I seem to remember some Actron scanners capable of scanning a 1.5 system but I think that they were around $300 with the connector adapter. Maybe some one here has some better info for you regarding the cheapest way to get a 1.5 system scanned as I have never had to solve this problem.


George

 

The blazer now is 50/50 on the turn signals working. Ever time i hit the brakes they turn on now they don't blink they stay solid.