gm tech 2

[mike0714]

Hi every one i was looking for a gm tech 2 to reprogram my 2008 trailblazer i am geting

a po651 my turck will not start geting fuel and spark i think my pcm is bad i read the tech 2

will only reprogram up to 2007 i don't want to spend the money on one if it will not work on

my truck thanks mike

 

[HARDTRAILZ]

So what is you question?

 

[Mooseman]

Moved to proper section

It should be OK for 2008. I just used it on a 2008 Buick Enclave to reprogram a radio and I was able to do it using Tis2000 in pass-through mode.

Look at it this way. Even if it can't reprogram modules in your truck, it will eventually pay for itself if it prevents two trips to the stealership. Hell, I even have an ad in Kijiji (a better Craigslist) to do diagnostics for people so it is paying for itself.

Now, for your P0651 Sensor Reference Voltage B Circuit Open, this specifically says that you have an open circuit. Tech 2 won't make any difference here. You either have a broken wire or the sensor itself is bad.

 

[mike0714]

thank you

 

[mike0714]

i did get a po335 crankshaft sensor afther i put a new one i read

it has to be reprogram by the tech 2 will that sensor put out

po651 and keeping from starting

 

[Mooseman]

No. You need a CASE relearn (aka: crankshaft variation relearn). It would not cause any other errors and you can drive it indefinitely without it until you need an E-Test. There's something else going on with the P0651.

 

[mike0714]

thank you have to get a wire diagram and see if i can fix it

 

[mike0714]

will a bad fan clutch cause a open circuit

 

[Mooseman]

Maybe not an open circuit but anything is possible. It has been known to crap out the 5V reference but for the throttle body circuit. You could try unplugging it. Can't hurt.

BTW, link is in my signature for manuals, which include schematics.

 

[mike0714]

thank you i will unplug it and see if it will help if i open the butterfly she will run for 2 sec

 

[mike0714]

ok i unplug the throttle body still will not start i hook my meter to the plug i am geting 4 v 0.2v on two more wires i had some one hit the gas the numbers stay the same i down load scantool on my laptop hook it up in the truck and read the sensors i see the gas pedal sensor move up when i hit it put not the throttle body maybe my pcm is not good a while back i got codes that don't belong to the truck plus i am geting message saying service air bag and charge any way to take a pcm a part it had 4 screws in the back i took them off put the cover will not come off thank you guys

 

[Rabid82]

You either have a broken wire or the sensor itself is bad.

Where is that sensor?

 

[Mooseman]

I assume that you are getting the same error? Download the schematics and look at all the sensors that it feeds. I would more than likely assume a broken wire since it's detecting an open circuit, which means all the sensors are not getting the 5V reference and completing the circuit.

 

[Rabid82]

Thanks,
So far I've found 3, the throttle body(needs cleaned anyway), the accelerator pedal, and the tank pressure switch.
I don't know if it's related, but the tach died when it went into limp mode after coming to a hard stop

 

[Mooseman]

And if i am correct, that circuit also feeds the fan clutch as we have had issues with it buffering up that 5v circuit when it shorts out. Just for the heck of it, try unplugging the fan and see if it resolves it.