1999 Buick park avenue no communication to ECM

[rogers9c1]

hey guys long time no chat,my 98 lesabre was totaled and i picked up a very mint 99 park ave with ....296420kms on it.
All highway miles it is a Florida car so very rust free, im having some issues with it tho, first is the orange box that should show up around the PRND123 indicator to show what gear you are in does not always light up, and when its not lit up i cant start the car or have any communication with the PCM, im scratching my head here , old owner said it was the neutral safety switch inside the trans, but im now second guessing this, if anymore information is needed please let me know im at a loss here and could really use some advice. i paid 800 for the car and im trying not to dump a ton into it.

[cjski]

Check all fuses and grounds

[rogers9c1]

thanks for the reply, any tips on where some of the big grounds are for this car? ones that control the ECM BCM and so forth im having a hard time finding information on this car.

[cjski]

Go to Auto-zone .com and look for repair guides for your car in the repair guides in emissions look for component locations

[haro1225]

There should be a big ground on the front of the trans.

[rogers9c1]

thanks for the replys, I'm going to check tomorrow and see what i can find, I'll pull the ground and clean them, it's funny when i get the orange box to show up the car works perfectly. Very odd

[rogers9c1]

any other incite into this,all the grounds and fuses check out fine? cant start the car or talk to the ecm, no orange light over the P on the PRND.

[rogers9c1]

Just a update for every one it turned out to be a bad PCM popped a new one on from another 99 parkave did they key relearn process and she fired right and I'm golden.

[Jrs3800]

Thats not unheard of but it is not common place with the newer 98+ PCM's.. Odd, but glad you got it fixed..