Vehicle won't crank now.

[Marlon Tomera]

My daughter has a 2012 GMC Denali XL, at first it lost oil pressure, so we replaced the oil pressure switch, after the vehicle got to operating temperature we started loosening oil pressure again. We went ahead and replaced the oil pump pickup tube. Once again after the vehicle reached operating temperature we lost oil pressure. The vehicle has been setting up for about a month now, my son-in-law pulled out the oil pressure switch and was going to check the pressure manually, but his kit didn't have the right fitting , so he removed the filter and installed the old oil pressure switch and went to crank the engine and it wouldn't start, even when you jump it. What could be causing this?

 

[Fless]

Welcome to TYF.

Is this a "no crank" or a "crank but no start" situation?

Does the engine turn over?

 

[swathdiver]

My daughter has a 2012 GMC Denali XL, at first it lost oil pressure, so we replaced the oil pressure switch, after the vehicle got to operating temperature we started loosening oil pressure again. We went ahead and replaced the oil pump pickup tube. Once again after the vehicle reached operating temperature we lost oil pressure. The vehicle has been setting up for about a month now, my son-in-law pulled out the oil pressure switch and was going to check the pressure manually, but his kit didn't have the right fitting , so he removed the filter and installed the old oil pressure switch and went to crank the engine and it wouldn't start, even when you jump it. What could be causing this?

Welcome to the forum Marlon. Check for loose wires from messing with the oil pressure switch. Keep us posted.

 

[Doubeleive]

could be a couple things
1. dead battery or bad cell's in battery
2. corroded or dirty, loose battery cables
3. not in park or neutral
4. bad ignition or security module sensor
5. faulty/bad starter
6. bad fuel pump
7. blown fuse
all depends on what you define as "no start"
1. does it turn over and just wont run (idle)
2. does it just "click" and no starter function
3. does nothing at all, if it does nothing at all is the "security" symbol light it up (looks like a little padlock with a car next to it)
any messages on the display?

 

[Marlon Tomera]

Welcome to TYF.

Is this a "no crank" or a "crank but no start" situation?

Does the engine turn over?

No it won't even turn over.

 

[Marlon Tomera]

could be a couple things
1. dead battery or bad cell's in battery
2. corroded or dirty, loose battery cables
3. not in park or neutral
4. bad ignition or security module sensor
5. faulty/bad starter
6. bad fuel pump
7. blown fuse
all depends on what you define as "no start"
1. does it turn over and just wont run (idle)
2. does it just "click" and no starter function
3. does nothing at all, if it does nothing at all is the "security" symbol light it up (looks like a little padlock with a car next to it)
any messages on the display?

If it deals with the security system, how do you check and fix that?

 

[Doubeleive]

If it deals with the security system, how do you check and fix that?

if the security light is on then you can try a 30 minute relearn, if the 30 minute relearn does not work then you may have a bad ignition switch or security module (it fits around the ignition)
here is the procedure for a key relearn if there has been a error.

 

[Marlon Tomera]

My daughter has a 2012 GMC Denali XL, at first it lost oil pressure, so we replaced the oil pressure switch, after the vehicle got to operating temperature we started loosening oil pressure again. We went ahead and replaced the oil pump pickup tube. Once again after the vehicle reached operating temperature we lost oil pressure. The vehicle has been setting up for about a month now, my son-in-law pulled out the oil pressure switch and was going to check the pressure manually, but his kit didn't have the right fitting , so he removed the filter and installed the old oil pressure switch and went to crank the engine and it wouldn't start, even when you jump it. What could be causing this?

Update to this post: All fuses are good, battery tests good, good battery connections, the new oil pressure sensors top spins, we also it leaking oil and had oil in the electrical connector. We have not been able to find the right fitting for the oil pressure test kit. When the key is turned to the on position, the instrument panel lights up and the radio lights up, but vehicle still won't crank. We will install a new oil pressure sensor tomorrow and see if the vehicle cranks. If it doesn't then we will have to start looking at checking out the wiring. This one is really stumping us. Any ideas would be greatly appreciated.

 

[Marlon Tomera]

if the security light is on then you can try a 30 minute relearn, if the 30 minute relearn does not work then you may have a bad ignition switch or security module (it fits around the ignition)
here is the procedure for a key relearn if there has been a error.

View attachment 244025

Security ligh does not come on.

 

[Doubeleive]

check the starter