qzilla

I am not sold that the harness is the issue but, you will have a new one tomorrow.

The reason I am not sold is that an underboost code almost has to have the 5v line shorted out in one way or another.

Normally if the harness is just bad or has a bad crimp or splice or something you should see a rail pressure high code and that should combine with other codes.

Now, I am talking normally, anything can and will happen so tomorrow let us know if this solves it.

H8GAS

I don't know much about electrical systems in vehilces so I am definately looking to you and others here for advice. That being said, I am certailn that the connections you were talking about were not on backwards. I did not have to manipulate the locking tabs on the plugs at all to get them to go in and the tab did go over the ramped portion. I used dielectric grease and pushed the connections together as much as possible. Is there any other possible problem that could be causing the 5v line to short? I want this product to work out for me. Thanks for the advice I know it is probably frustrating to try to diagnose problems without seeing the truck.

Also, when I checked all the connections and after using the dielectric grease I checked the codes again and still saw P0192 but P0111 has now popped up.

JHeiser

Hey I am not an expert by any means but something you might try if you have a volt/ohm meter. Try ringing out the wiring harness which is rather easy. Completely disconnect the XZT wiring harness from the truck. If you have a volt/ohm meter set the meter to check ohms, stick one of the probes (needle tip if possible) into the connector in such a way that only one pin/wire is in contact with the probe. Take the other probe and touch other pins in the connector. The needle/display should not move except when you touch the other end of the same wire. If the needle/display does jump/move when you touch another pin it’s a pretty good indication there is a short between pins/wires. Another check is to set the meter to check ohms, stick one of the probes into the connector ensure contact with only one pin, trace the wire you have the probe in contact with to the other end and using the other probe touch the pin/wire in the other connector that corresponds to the other end of the wire. In this case the needle/display should jump/change. If it doesn’t this is a good indication of a bad wire or connector. Do this to each of the various connector pin/wire pairs. A buddy had a similar problem to yours and it turned out that he had not seated the connector that goes into the little under the dash module completely. When I installed mine before we started the truck I had him check the connections and sure enough the connector to the module was not completely seated.

I hope you get it worked out. I love my XZT module and for sure would recommend it anyone looking for that little extra getup and go.

H8GAS

I don't have access to a volt meter, but I will look for one. I wil also recheck that in-cab connection....so far that has not been one that anyone said could be an issue.

H8GAS

I'm just curious...if something was loose (I rechecked the in-cab connection) and I fixed it shouldn't this thing fire right up without the excessive noise? I don't know if it needs to be driven for a bit so that the computer could recognize the change. I would like to avoid driving it like this right now, but obviously I would if necessary. I know that the codes might not go right away, but the noise??

qzilla

If you have any doubts drive it stock for a few miles.

Also make certain that you do not get to over obsessive about this or you will hear things that do not exist. If your truck is cold it will be a little noisy no matter what. If you have any doubts you can plug the harness in and install the bypass plug. Run it until you deem it normal and then replace the bypass with the module and go from there.

H8GAS

Just wanted to give an update on this situtation.

When I got the new wiring harness installed I had the same exact problems. I sent my harness and module to Quad and a tech looked at them. Turned out I had a bad module. They sent me a new module that I installed yesterday and all appears to be OK. There is no more rattle at idle and no codes were thrown (I took the truck to the dealership and had the codes cleared while I was waiting for the new module).

I haven't had a chance to drive the truck much but a quick drive felt good. The truck seems to have a little more pep! I will put a few tanks of fuel through it and see if my milage increases at all.

All and all I was satisfied with the way things turned out. I had to spend about $15 to ship everything back to Quad which sucked and the time I placed my original order to the time I got a product that worked was about three weeks. But now I have everything working properly (I hope) and hopefully I will be happy with the XZT over time.

JHeiser

H8GAS,
Sounds like you have it all taken care of. I hope you like your XZT as much as I like mine. I feel it was well worth the money.

JH