So last week truck wouldnt start. Turn over but no fire. Finally took it to the dealership. They said the on board computer was junk. Good news that has a 8 year 80,000 mile warranty on it. Bad news truck still wouldnt start. Now they are saying it is the Smart Junction Box. Also know as the GEM. Said it is pulling too much volts from the coil and not allowing to start.Is this really the problem or am I getting taken on a ride? cost will be around $700.

Would be thankful for any input..

 

What truck? what engine? sure sounds like there doing diagnostics through parts replacement... But you say you have the warranty so who cares long as they fix it.

 

It is a 06 F 150 5.4 and no it doesnt have a warranty. the computer had a warranty on it.

 

ask to speak to the technician working on the car. see if he seems competent.

make sure that if you approve the work and it doesnt fix it that you aren't paying for their errors and misdiagnosis

 

I replaced the GEM on my sisters Lincoln and it cost me $260.00 from NAPA. The $700.00 sounds far too expensive to me. I'd be looking for one in a junk yard before bending over for that one. It's a no brainer to replace and took me about 15 minutes to replace. BUT, did you notice the brakes getting hard before this happened? If so, it's probably the GEM. If not, I think they're guessing and have no clue.

 

My wife drove it to work came out would not start. I did get it started drove it about 15 miles ran fine then would not start again. no issue with brakes

 

I'm gonna doubt the GEM is bad. Usually when they start going bad the brake pedal starts heading for the floor as the hydraboost doesn't work like it should. What I'd try next is to drive the truck with a set of jumper cables in the truck. When it doesn't start, I'd jump the negative side of the battery to the engine. If it starts, then the ground strap is bad and it's an easy fix- just run another one. It's worth a try and it won't cost you nothing but yer time.

 

It wont start now. can I still try your suggestion? Also I am going to assume the smart junction box controls everything electrical? if that was the case wouldnt there be more problems? thanks man