DEAD VEHICLE - LSJ Won't Crank/Start

I've been tweaking a few idle settings and then doing a quick scan and everything was going fine. Then it just sits there like it's still receiving a tune. The dash displays "POWER STEERING" and rotates through a couple of other normal messages. No HE pump anymore, no Trip A/B or any other info other than the ODO. Turning the key will just give a relay click in the BCM and nothing else. None of the software (even the Beta) is able to communicate with it anymore. Tried disconnecting the battery, power steering, other key, and removed the AEM OBDII scanner. I need some help getting this car to run again. The software doesn't even see the car and cannot determine the protocol.

Ive never experienced this issue ... ive only had a failed to load tune before which it worked then after but im still using the mpvi1... are you using the new mpvi2? if so create a ticket with hptuners to try to get this sorted ... maybe try doing a write entire? but by not having communication to the ecm i doubt that would work but i suppose its worth a shot before you go out and get a new ecm .. i work at a chevy dealer and had some luck a couple of times doing a replace/reprogram through gmtis due to the battery dying mid flash but not always

you lost communication mid flash. take it to the dealership they have to try and speak with it using a tech2.

some things that are critical when flashing. never have any accessories turned on. when the computer cycles the bcm systems it also cycles any circuits left on. this causes a voltage dip that can cause major issues. also, always keep a window rolled down and lock your doors when friends are around. any opening of doors can disturb the can system and cause com loss or voltage dip when the lights come on.
always make sure the battery is good before testing. check voltage at rest and voltage under cranking to verify amp supply is sufficient. if its older than a year i refuse to flash without a battery charger active on low amp mode (typically 2amps)

also beware that the mpvi cable sockets can loosen and disconnect when held at an angle. almost screwed me over once.

You guys have been a great help. Up to this point, I wasn?t sure what was going on but you pretty much confirmed it for me. I put in a support ticket but hasn?t been much help. From what I?m reading, the new software is prone to bricking ECMs. I?ve ordered another P12 to see if I can make it work for me. Really bummed about not being able to drive the car for days.

Your right, the new Beta doesn?t work either, it just won?t communicate at all. I?ve tried about every suggestion out there to try and get it back, I?m afraid it?s toast. Almost afraid to even use it anymore, at least not without spare ECM.

There has been just released another update from my previous post. This one brought it back to life!!!! New Beta software and firmware. It seems to work much better now also, no longer getting the time-outs.

Here are a couple of shots of the car in question.

Thanks to HP Tuners for getting on this so quick and getting me back on the road!!!:)


Attachment 81005Attachment 81006Attachment 81007Attachment 81008Attachment 81009

Just wanted to give a quick update that I should have a long time ago. I finally figured out the reason for all of my troubles. I have an AeroForce scan gauge hardwired into my OBDII port all the time and it was causing all of the write issues! Once I unplugged it, I have never had another bad write whereas before I was having 1 out of 5 bad writes. I should have known but frankly forgot all about it since it was hardwired in and not actually occupying the port. Not sure how many others may every have this issue but it's worth putting out there. Two years now and I have been trouble free!

CAN interruption 80% of the time. Good you figured it out.

Thanks for the update.

Really dig your vehicle.
Can you imagine some politicians and their constituents hate everything about what your vehicle stands for. If they had it their way (and they will eventually), we'd be driving 80 horsepower cars limited to 0.1g's of acceleration and a mandatory speed limiter !

It's no coincidence why the 1st and 2nd Amendment's are 1st and 2nd on the list. And I'm not even American.

I'm sorry for derailing your thread. You have the right to delete my post.