Chevy trailblazer 2007 no start Help

[ajman5252]

I have trailblazer in shop in which customer accidentally swapped terminal of battery

there were couple of fuses blown which we replaced and now we have car with all fuses and relay ok. triple checked it!!! Everything is working now, AC, radio and remotes.... except engine cranks but wont start

This car doesnot have transponder in key, anyways i tried 10min x 3 procedure but the security light(padlock) keeps on blinking even after 10 mins wait

Can anyone share any knowledge or light on how to start this car??

[ajman5252]

by the way...i check the fault codes and i found i have P1631 present in it( theft deterrent start enable signal not correct)

What are my options

[camelgd]

The American version has what GM calls "Passlock", which is an MRD set up in lock cylinder. Plug has a magnetic chip, housing has reader on it and it reads the value of chip as it passes by. It's called a Hall effect sensor. It sounds like, from the code, that the sensor on the housing got fried. Can't be positive, cause reversed polarity down wires can play havoc with a lot of things.:joyous:

[ajman5252]

i did a research a found exactly same thing..but my question

by replacing it, will it start the car??

or does it need reprogramming??

[camelgd]

Should be a 3 X 10 min. program..., but that is when you change the ignition cylinder. When you change out the lock cylinder on MRD, you have a one in 10 chance of not having to program. There are 10 different magnet values. I just don't know if you will have to reprogram 3 x 10, because you aren't changing the cylinder, just the reader. You should know immediately, if no program, should start up first time without 3 x 10. Sorry I can't help you more, kinda drifting off into areas I have not messed with. Have changed quite a few MRD lock cylinders, 0 problems reprogramming with 3 X !0. One last thing that you may need to check also, there is a separate fuel cut off breaker on this type of vehicle, if keys are programmed and still doesn't start, location should be in owner's manual or on fuse covers.