C5 Crank but wont start issue
Thread Starter
8th Gear
Joined: Apr 2024
Posts: 8
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C5 Crank but wont start issue
Hey Forum. Im new here and in need of help for my 2001 base c5(manual). Thanks guys!.
So my C5 will sometimes start, but will abruptly die with no warning. Then it will not start back up for a while. It started when i let the car sit without starting for about a month. Charged up the battery and it had a code P1518. I cleared it and the issue seemed to go away for a 2 days. Starts fine cold, but will eventually shut off after. 5-10 minutes with no warning. No codes come up, however now im getting the “pull key wait 10 sec” a bit more often now. Im scared of taking it for a drive. Bad battery?(as this is not the first time i had to jump it) ignition switch? Tps? (I don't get the reduced power message and while the car is on, it pulls strong). Any help guys? Thanks
So my C5 will sometimes start, but will abruptly die with no warning. Then it will not start back up for a while. It started when i let the car sit without starting for about a month. Charged up the battery and it had a code P1518. I cleared it and the issue seemed to go away for a 2 days. Starts fine cold, but will eventually shut off after. 5-10 minutes with no warning. No codes come up, however now im getting the “pull key wait 10 sec” a bit more often now. Im scared of taking it for a drive. Bad battery?(as this is not the first time i had to jump it) ignition switch? Tps? (I don't get the reduced power message and while the car is on, it pulls strong). Any help guys? Thanks
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,643
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From: Cape Coral, Florida
While the car is cranking but not starting look at your Tach…if the Tach doesn’t move it may be a bad crankshaft position sensor…you will have no injector pulse or spark.
Melting Slicks
Joined: Nov 2014
Posts: 3,399
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From: Havre de Grace Maryland
Another possibility is the ignition switch. When I inserted/pulled key out of ignition for many times it would finally start. My go to Vette mechanic replaced the ignition switch. It took 4 new switches with GM makings on box and switch but made in China crap-ola before one worked. But for how long 
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Thread Starter
8th Gear
Joined: Apr 2024
Posts: 8
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YUP! The tach stays perfectly still while cranking. Also, before i crank it, im only seeing 11.1V on the battery (dash reading)
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
If you’re reading 11.1 on DIC which is NOT true battery voltage it’s around 11.5 on the battery which is about 20% charged so it’s basically a dead battery…how old is your battery ??…get your battery checked then address a “possible” bad crank sensor.
Thread Starter
8th Gear
Joined: Apr 2024
Posts: 8
Likes: 1
Heading to autozone now to load test it. But yes, basically with the key in the “on” position, the dash reads 11.1-11.5v
Thread Starter
8th Gear
Joined: Apr 2024
Posts: 8
Likes: 1
[QUOTE=C5 Diag;1607717998]If you’re reading 11.1 on DIC which is NOT true battery voltage it’s around 11.5 on the battery which is about 20% charged so it’s basically a dead battery…how old is your battery ??…get your battery checked then address a “possible” bad crank sensor.[/QUOTE
It started on the try after “charging” the battery for about an hour but died soon after i turned on tje hazards and AC. . Dash reads 11.4 when the key is in the “on” position. No weird flickering, no check engine light and no “reducer power” message. Will change the battery tomorrow and check in after🫡
It started on the try after “charging” the battery for about an hour but died soon after i turned on tje hazards and AC. . Dash reads 11.4 when the key is in the “on” position. No weird flickering, no check engine light and no “reducer power” message. Will change the battery tomorrow and check in after🫡
