I have a 2001 LT 4door w/ 4.3, i issue is that when i pull something behind the vehicle or go up a hill and the blazer shifts down and is pulling hard the check engine light will start to flash, if i continue to the top of the hill and within a mile or two the light resets and all is well, or i can reset the light by shutting the vechicle off and restarting it. The problem is that vehicle will not set any kind of code so that i can find out what is wrong, has anyone has something similar to this and if so what was the cause.

any help would be much appreciated

 

usually if the check engine light flashes it means that it is some sort of misfire code. if you have a good scanner it will usually bring up the history codes and tell you want it is

 

i had auto zone check for codes and there are not any.

 

The flashing engine light is normally a misfire or knock, like abig84 said. It's really weird that the light would come on without setting any kind of code. You might want to pick up a scanner, and check for codes the next time the light goes off, or go to a mechanic or dealership that has a high end scan tool. I have come across dealerships that will read your codes for you without charging.

That being said, when was the last time your truck had a tune up? Plugs, wires, rotor, etc.

 

Can someone help i have a 01 blazer LT but when i hook up code reader it shows no codes but will not show my catalytic is on nor emissions nor Egr i had battery disconnected reconnected it but when i took it to get inspected it did not hookup or show these as being connected,please tell me it is not a ECM that needs to be replaced

 

You should probably start a new thread, but...

After the battery is disconnected and reconnected, the emission system needs to run a series of self-tests (called monitors) before the system is "ready". Since different driving conditions need to be met for each of the monitors to run, it can sometimes take hundreds of miles of driving before they are all complete, assuming the self-tests don't reveal any problems. Until most of the monitors are complete, the vehicle cannot be smogged.