Hey guys, did a little searching online and found this website. Maybe someone on here can help. Lately my truck has been making a hissing sound coming from somewhere around the sending unit/fuel lines. When it hisses, the truck cranks over about 10 seconds before it starts, like it's not getting any fuel. 

 

The airdog always runs 15 psi. The truck will always start right up within about 15 minutes of shutting it off. But if I let it sit for a few hours, it may or may not start right up. It also seems like this hissing sounds is related to starting. More of a hiss, the harder the start. Maybe I'm thinking too far into it. Has anyone ever seen this before?

I FOUND THE FIX!! 

 

Hello All,

 

For anyone with an engine light that contains a p600 code (there may be others too such as fuel calibration, map voltage, or IAT voltage, etc.)

 

ISSUE: I had no wait to start light as well as strange throttle responses as if the APPS were failing (mine was not, it tested perfect).  

 

The issue was a corrupted ECM.  I decided to send the ECM to Auto Computer Specialist in Florida and they did a great job flashing it and it resolved ALL issues.  I had a p602 code (among others) which according to them was due to bad terminals and batteries.  I had two family farm and home batteries (with aging terminals as MI salts roads) and they apparently could not survive a Michigan winter.  

 

So, if you have a 2001 with any p600 codes they informed me this is due to the batteries and terminals creating a voltage surge to the ECM corrupting the main processor...  This is the main cause of a 600 code.  There is also a limited number of times they can clear this but I am hoping that I never have to do it again...

 

Hope this helps the next guy and sorry it took so long to post.

 

-Dave

 

 

Edited June 6, 20186 yr by Daveb

Did they do any repairs to the ECM or simply just reflash it?

Might look into the ground wire mod by @W-T .