1996 grand am no power to pcm

Hello everyone,
I am having a problem with my 96 grand am se. It has 2.4l engine with 93000 miles. I have no power to pcm. I have checked fuses
coil packs, fuel injectors, fuel pump, ignition, etc. Everything checks out okay there. Car will not start, it cranks but thats it. All lights and gauges working checked all my grounds ok there too. also transmission wont come out of park unless i pull cover to gear shift selector and push plastic tab to side. It is an automatic. I am thinking fusible link or bad pcm. any help in this matter would be greatly appreciated. Thank you. The fuse for pcm is good but no power to it.

Have you checked your fuseable links? (they attach to the starter where the positive battery cable attaches) since you have multiple power issues there is a good chance one of those could be bad.

when I bought my 95 quad 4 it wasn't running, after I did all the engine work to it, I couldn't get it to fire, ended up being a bad power wire going to the computer, not sure where or why it was bad, it just was. Check your fuseable links first!

If your computer is powering up your check engine light will turn on when you turn the key forward, if your not getting this check to see that your getting power to the computer at all times, after that there should be atleast one wire that comes from the ignition telling the computer to turn on, see if you have power there, after you know you have power everywhere you should have it then I would lean twards the computer.

A Haynes manual isn't the best solution for finding these wires going to the computer (its rather vague), I had my buddy bring his book home from the GM dealership, it was much better, if you don't have a mechanic buddy that can bring one home, go talk to someone at in service at a dealership sometimes they will help you out, tell them what wires your looking for and they will probably give you the info. On the computer end they are all labeled by number and letter.

Check the fuse that controls the memory to the radio, if thats blown then your ecm is not getting power and thats why you can't shift out of park. For some strange reason almost every manufacturer uses this fuse to control these things.

Have you checked your fuseable links? (they attach to the starter where the positive battery cable attaches) since you have multiple power issues there is a good chance one of those could be bad.

when I bought my 95 quad 4 it wasn't running, after I did all the engine work to it, I couldn't get it to fire, ended up being a bad power wire going to the computer, not sure where or why it was bad, it just was. Check your fuseable links first!

If your computer is powering up your check engine light will turn on when you turn the key forward, if your not getting this check to see that your getting power to the computer at all times, after that there should be atleast one wire that comes from the ignition telling the computer to turn on, see if you have power there, after you know you have power everywhere you should have it then I would lean twards the computer.

A Haynes manual isn't the best solution for finding these wires going to the computer (its rather vague), I had my buddy bring his book home from the GM dealership, it was much better, if you don't have a mechanic buddy that can bring one home, go talk to someone at in service at a dealership sometimes they will help you out, tell them what wires your looking for and they will probably give you the info. On the computer end they are all labeled by number and letter.

Thanks the fusible links were going to be my next step. You are absolutely right the haynes manual is very vague. I have a few mechanics as friends but they don,t have a diagram for me, will keep searching. Thanks again

Check the fuse that controls the memory to the radio, if thats blown then your ecm is not getting power and thats why you can't shift out of park. For some strange reason almost every manufacturer uses this fuse to control these things.


I will check that as well. Replaced the radio years ago don,t remember seeing a fuse, but will look for it. thanks for the info

I will check that as well. Replaced the radio years ago don,t remember seeing a fuse, but will look for it. thanks for the info
Okay Im back again still same problem, got a gm service manual rechecked fusible links all are good replaced crank position sensor, cam position sensor had pcm checked and flashed. reinstalled pcm tonight same deal cranks but doesnt start. I am getting no power to ignition coils
fuel system neutral safety switch and no power to quite a few fuses. there is power coming into pcm but nothing going out. Where should i head to next. totally stumped.

Check the fuse that controls the memory to the radio, if thats blown then your ecm is not getting power and thats why you can't shift out of park. For some strange reason almost every manufacturer uses this fuse to control these things.

the fuse skibum1111 was refering to is the fuse that controls the radio in the fuse pannel. if your radio works then thats not it, I believe there are 3 power wires to the computer, the main red (all the time power) was my bad one, use the GM Service manual to find the main power wire on computer connectors. If you have power there find the other one or two power wires and check if you have power there with the ignition on.

**** those gm manuals tell you what to check step by step if you can understand how to work your way thru them. they are great once you understand them. if you have any direct questions I will try to help.

****** the pcm (computer) does not feed power out, it feeds a ground out, all of the power to run everything is coming from your fuse pannel, all the computer does is connect a ground to make things run.

******** if the computer is powering up your check engine light will come on when the ignition is turned on without starting the car

follow the diagnostic steps, it will get you to the root of your problem.

the fuse skibum1111 was refering to is the fuse that controls the radio in the fuse pannel. if your radio works then thats not it, I believe there are 3 power wires to the computer, the main red (all the time power) was my bad one, use the GM Service manual to find the main power wire on computer connectors. If you have power there find the other one or two power wires and check if you have power there with the ignition on.

**** those gm manuals tell you what to check step by step if you can understand how to work your way thru them. they are great once you understand them. if you have any direct questions I will try to help.

****** the pcm (computer) does not feed power out, it feeds a ground out, all of the power to run everything is coming from your fuse pannel, all the computer does is connect a ground to make things run.

******** if the computer is powering up your check engine light will come on when the ignition is turned on without starting the car

follow the diagnostic steps, it will get you to the root of your problem.
Thats what I've been doing is following the diagnostic steps in the manual, I'm by no means and expert on electrical schematics barely a novice if you will. I have a friend helping me who is a retired mechanic
unfortunately he retired from that before all the new computer stuff came out. The steps I've completed so far is mostly from the service manual,some advice from a current gm mechanic. I will just have to keep at it. Thanks for your time and advice.

Thats what I've been doing is following the diagnostic steps in the manual, I'm by no means and expert on electrical schematics barely a novice if you will. I have a friend helping me who is a retired mechanic
unfortunately he retired from that before all the new computer stuff came out. The steps I've completed so far is mostly from the service manual,some advice from a current gm mechanic. I will just have to keep at it. Thanks for your time and advice.


my sister has a 91 GA
it had a no start problem
after beating my head against the wall for about a month
i noticed the check engine light wasn't coming on in the bulb test position in the ignition

i check the fuesable links
they all seemed good
so i un hooked the computer
tested for power at the connector
and found that the fuesible link wire(the on i checked)
was bad after the spot were it was connected to the fuesable link part
it was an orange wire
it was in the haneys manual

i would disconnect the computer connector and test for power there
and work your way back out to the engine compartment