LS3-No Start-Error-No Codes
Thread Starter
Teching In
Joined: Jul 2020
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LS3-No Start-Error-No Codes My LS3 w/4L65E is in a state where it cranks, engine indicator in gauges shows error briefly, does not send any codes to read or clear.
I've checked the 8 fuses in the engine harness, and they are fine. The fuses in the main panel are the type that light up when failing, so at this point, I have not pulled any of them to check out.
Any suggestions on were I should evaluate the issue?
I've checked the 8 fuses in the engine harness, and they are fine. The fuses in the main panel are the type that light up when failing, so at this point, I have not pulled any of them to check out.
Any suggestions on were I should evaluate the issue?
TECH Regular
Joined: Aug 2007
Posts: 405
Likes: 42
My LS3 w/4L65E is in a state where it cranks, engine indicator in gauges shows error briefly, does not send any codes to read or clear.
I've checked the 8 fuses in the engine harness, and they are fine. The fuses in the main panel are the type that light up when failing, so at this point, I have not pulled any of them to check out.
Any suggestions on were I should evaluate the issue?
I've checked the 8 fuses in the engine harness, and they are fine. The fuses in the main panel are the type that light up when failing, so at this point, I have not pulled any of them to check out.
Any suggestions on were I should evaluate the issue?
Thread Starter
Teching In
Joined: Jul 2020
Posts: 47
Likes: 4
I just came back here to mention something I found. @LS1 TJ , I think you nailed it.
During dinner, I had happened to remember that I had a fuel pressure gauge on the engine. I'm not seeing pressure.
So at least I have something to chase. My plan on things to check related to that:
Thanks, guys for the input. It is appreciated.
During dinner, I had happened to remember that I had a fuel pressure gauge on the engine. I'm not seeing pressure.
So at least I have something to chase. My plan on things to check related to that:
- Fuses
- Relays
- Wire connections
- And finally the pump itself
Thanks, guys for the input. It is appreciated.
Thread Starter
Teching In
Joined: Jul 2020
Posts: 47
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Success! The short answer is it was the relay to the fuel pump. Below is the longer answer how I proceeded to get to that conclusion for those who may interest.
This morning I checked the fuel pump fuse, and it was good; then checked the fuse port to see if it was getting power, it was.
So I turned the ign on, and got under the car to see if the pump was receiving power: Nope.
I pulled the relay to see if the power feed was providing power: yes
I put in a different (not new) relay; still no joy.
So at this point I was needing to determine for sure if the fuel pump was good before I started chasing the PCM. I checked my documentation to identify which relay port fed the pump, and I supplied power to that, and the pump ran. That was good news.
So I put yet another relay I had laying around (Probably should get a new one), and it worked. So, I'm good to go now.
This morning I checked the fuel pump fuse, and it was good; then checked the fuse port to see if it was getting power, it was.
So I turned the ign on, and got under the car to see if the pump was receiving power: Nope.
I pulled the relay to see if the power feed was providing power: yes
I put in a different (not new) relay; still no joy.
So at this point I was needing to determine for sure if the fuel pump was good before I started chasing the PCM. I checked my documentation to identify which relay port fed the pump, and I supplied power to that, and the pump ran. That was good news.
So I put yet another relay I had laying around (Probably should get a new one), and it worked. So, I'm good to go now.
Last edited by Kruiser; Mar 20, 2021 at 02:47 PM.
