I am new to this site I am truly struggling with this 02 trailblazer 4.2 4x4 changed the battery now it won't crank and I have no gauges or communication with the tech 2 or mac scanners have checked fuses relays and so on any one got a direction for me to go
No start no crank
- Thread starter Sscrash
- Start date
Did it crank or have gauges before you changed the battery? More history here might be very useful
Yes it did say for about a year started and drove put new battery in and now no crank no start no gauges no radio no communication at port we do have all dash lights and auto lights fuel pump comes on replaced ignition switch checked and actually replaced all fuses and relays plus test all of them again
Mooseman
Moderator
Did you also check the 125A mega-fuse?
We also have this from the FAQ:
No Crank, Like Attempting To Start In Drive
But you seem to have deeper electrical issues. You should check the power outputs at the ignition switch.
We also have this from the FAQ:
No Crank, Like Attempting To Start In Drive
But you seem to have deeper electrical issues. You should check the power outputs at the ignition switch.
Mooseman
Moderator
Have tested all wires at ignition switch after replacing because that was my first thought the way it acted was the switch all wires test properly not going where it needs from there I guess
Mooseman
Moderator
Since problems started with the replacement of the battery, are you sure it's good, fully charged and has a good solid connection? I once had a new battery that was junk. Batteries sometimes sit on the shelf a long time and could have self discharged.
Sounds to me like it may be a battery connection issue. Go back to the battery and check the cables, make sure there's 12v at the other end of the cables, and that the connections are clean and tight.
Were there any sparks when you hooked up the new battery?
Were there any sparks when you hooked up the new battery?
I have had the battery in and several times and yes I believe there was sparks come to think of it but connections are good voltage at battery back of alt main line to starter don't know where else to turn
I just had a look at the ground distribution wiring diagram. You previously said no data comm with scanner, no radio, and so on. Several of these are grounded via G102 at the left rear of engine compartment. Have a look at the wiring diagrams and see what items don't work and where they are grounded.
ok so it would appear you have "good power" coming from the battery. Go to the start relay and check for voltages there before and after a "start attempt"... what do you read?
I have done that as well remain the same almost like it is not rotating the ignition switch but have replaced it rotated it by hand as well all power to the switch as well
Yes I have proper power at the relay but it will not switch over doesn't get signal/power from ignition
BUT your statement is NOT clear. The "signal power" (what ever that means) has nothing to do with the ignition switch (ie. it is NOT in the circuit). Only thing in the circuit is the battery, the park neutral switch, and the PCM.
So you saying that you see "no ground" coming from the PCM to the start relay... right?
Lastly, then if so (no ground from pcm), then you have checked fuse 17 for proper voltage during start attempt?
So you saying that you see "no ground" coming from the PCM to the start relay... right?
Lastly, then if so (no ground from pcm), then you have checked fuse 17 for proper voltage during start attempt?
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That's what I am saying nothing is coming from the switch the auto lights come on fuel pump comes on hvac comes on wipers come on but no gauges and no radio and no crank
you have your issue identified then... until you get voltage coming to fuse 17 from the switch, you will get no start. Look at your switch install... check the wiring, red comes in with voltage and leaves on yellow during start attempt.
Maverick6587
Member
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Maverick6587
Member
I would check the switch power as budwich suggested. I would also check for power at the cig lighter outlet. If you don't have power at the cig light outlet, I would trace those wires.
TJBaker57 also had a great suggestion for checking the G102 engine ground. Those 4 grounds (that are all near each other in a square configuration) commonly look "OK" but, are in fact not making good enough contact for ground. While you're there I would remove all 4 nuts. Clean those 4 nuts and where they mate to on the engine as good as you can.
If you have some, I would apply some dielectric grease on the engine mating surface of those nuts. That should stop any grounding issues from happening in the near future.
TJBaker57 also had a great suggestion for checking the G102 engine ground. Those 4 grounds (that are all near each other in a square configuration) commonly look "OK" but, are in fact not making good enough contact for ground. While you're there I would remove all 4 nuts. Clean those 4 nuts and where they mate to on the engine as good as you can.
If you have some, I would apply some dielectric grease on the engine mating surface of those nuts. That should stop any grounding issues from happening in the near future.
Have power at cigarette lighter all grounds have been checked and now have unknown driver on dash but no security light jumped it at relay 47 will run until fuel rail is empty still won't crank from key no communication and no radio or gauges but have automatic lights
it is likely that your key switch was not installed correctly and the positions (run, start, access, etc) are not at the correct place resulting in the wrong "powerings". You need to check each position and the resulting power outputs and / or start over and re-install the switch.
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FWIW... If your vehicle sports this similar wiring harness connector adjacent the Start Security Mechanism... observe what this VOP (Video Original Poster) did to keep the Connector solidly in contact with the in-dwelling Electrical Contact Points. The fact that he has completely removed the Steering Wheel does NOT mean that this part of the procedure would be necessary... just tilt the Steering Wheel down and remove the upper and lower Plastic Steering Column Fascia in order to gain access to the places where he works to solve his intermittent No Start issues.
If it were me... I'd not only insert a length of the Thin Plastic ZIP Tie down into the female portion of the socket to snug things up... I would've left a long enough end sticking out and then wrap ANOTHER thin ZIP Tie around the stem of the jammed in piece and then cinch it up to the upper Connector Wires so that it would not "Pop Out" afterwards from normal operational vibrations:
If it were me... I'd not only insert a length of the Thin Plastic ZIP Tie down into the female portion of the socket to snug things up... I would've left a long enough end sticking out and then wrap ANOTHER thin ZIP Tie around the stem of the jammed in piece and then cinch it up to the upper Connector Wires so that it would not "Pop Out" afterwards from normal operational vibrations:
Maverick6587
Member
Mooseman
Moderator
I found this thread that may be related to your UNKNOWN DRIVER message and was caused by water in the PCM connector. If that's the case or a problem with power or ground, it may be related.
gmtnation.com
Unknown driver, warning lights, not quite like this issue in other forums
Okay everyone, I’ve exhausted the forums searching for a solid diagnosis for this. Nothing hits right. I have guesses, but don’t want to start throwing expensive parts at it. Any help before going to the repair shop would be most appreciated, especially since I’m not convinced a shop can figure...
gmtnation.com