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Discussion Starter · #1 ·
Hey everyone, new here so excuse me if this isn’t the right place for it, but I have been having a crazy amount of problems with my 04 lb7 lately. The first day I had the truck I got it home and when I put it in park it went into limp mode, check engine light on and no indicator on the dash for the gear selector, figured the nsbu went bad so I replaced it with the tan updated one. Still had a black one... that lasted a month and a half and it happened again yesterday and left me at Walmart, replaced it yet again with a free one because they warrantied it, I made it home 8 miles and it happened yet AGAIN... no gear indicator, check engine light and limp mode. I’m at a loss as to what I need to do, there’s no way I’ve had 3 bad switches in a row, the truck has a suncoast trans, PPE triple disk converter and is tuned with efi live if it makes a difference... I rely on this truck for just about everything so I really need to figure this one out, thanks guys!
 

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Hey everyone, new here so excuse me if this isn’t the right place for it, but I have been having a crazy amount of problems with my 04 lb7 lately. The first day I had the truck I got it home and when I put it in park it went into limp mode, check engine light on and no indicator on the dash for the gear selector, figured the nsbu went bad so I replaced it with the tan updated one. Still had a black one... that lasted a month and a half and it happened again yesterday and left me at Walmart, replaced it yet again with a free one because they warrantied it, I made it home 8 miles and it happened yet AGAIN... no gear indicator, check engine light and limp mode. I’m at a loss as to what I need to do, there’s no way I’ve had 3 bad switches in a row, the truck has a suncoast trans, PPE triple disk converter and is tuned with efi live if it makes a difference... I rely on this truck for just about everything so I really need to figure this one out, thanks guys!
Look at the wiring harness, those very small wires chafe and short out. The fact that replacing the NSBU switch seemed to solve it for some period of time tells me you are in the correct location/

I am betting if you simply disconnect it and then replace it you will have the same temporary fix. So look very carefully for the chaffed wires and tape them up
 

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The internal wiring harness is a known problem area on older trucks. You way want to investigate that. It does require dropping the pan and valve body.


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Discussion Starter · #4 ·
Alright I’ll look over the nsbu wiring closely, also my abs light is on all the time and the service brake system pops up randomly all the time and then will go away if I get on the throttle kinda hard, related at all?
 

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Discussion Starter · #5 ·
Hey everyone, new here so excuse me if this isn’t the right place for it, but I have been having a crazy amount of problems with my 04 lb7 lately. The first day I had the truck I got it home and when I put it in park it went into limp mode, check engine light on and no indicator on the dash for the gear selector, figured the nsbu went bad so I replaced it with the tan updated one. Still had a black one... that lasted a month and a half and it happened again yesterday and left me at Walmart, replaced it yet again with a free one because they warrantied it, I made it home 8 miles and it happened yet AGAIN... no gear indicator, check engine light and limp mode. I’m at a loss as to what I need to do, there’s no way I’ve had 3 bad switches in a row, the truck has a suncoast trans, PPE triple disk converter and is tuned with efi live if it makes a difference... I rely on this truck for just about everything so I really need to figure this one out, thanks guys!
Look at the wiring harness, those very small wires chafe and short out. The fact that replacing the NSBU switch seemed to solve it for some period of time tells me you are in the correct location/

I am betting if you simply disconnect it and then replace it you will have the same temporary fix. So look very carefully for the chaffed wires and tape them up





So I was crawling around under it and I pulled the connector off that goes into the trans, the connector was full of tranny fluid, any chance that could cause my intermittent issues with a nsbu? I cleaned it all out well and drove it and it drove fine but what confuses me is it was acting up last night so I parked it, this morning I went out and when I fired it up I had my indicator and it was out of limp mode, on it’s own
 
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