I posted this in Electrical, but there was thought I might get more response here:


My 2003 went into the shop last week due to a loss of power. At anything above 1/2 throttle the truck would rev up to about 3500, then stumble, cough, gag and not shift up.

Dealership has looked at it all week. They say they see a communication error. They thought it was a PCM, replaced that and said that wasn't the problem. So now they say that after looking around that the problem is --- get this -- an add on stereo module that lets my MP3 / XM radio play through the radio. This module is a unit that has been in place for 1 1/2 years, and the problem just started 3 weeks ago. This module plugs into the back of the factory radio and gives an input using the AUX1 / AUX2 inputs.

They want me to pay well over $500 for diagnostic work and they say the radio module IS THE PROBLEM. The tech says he disconnected the module, drove around and the problem is gone, and then plugged it back in wanting to know what I want to do about it.

Is this a load of horse $4!t or what? Please let me know how this radio module (one that many people here are probably using) can cause loss of power and shifting problems?


EDIT: I removed the Edge/Attitude controller and the problem was still there. The dealership does not know I have one, and most likely would blame it instead.
Also, the fuel filter was replaced in the end of November and has less than 6k miles on it.

I would ONLY pay this if the tech can demonstrate it ie plug the module in - problem there -unplug module problem gone. Somehow I doubt they'll do this.

Go ahead and change the fuel filter or have them do it. It dont take long for them to stop up as mine has done it in less than 1000mi before. All it takes is one tank of dirty fuel. Eliminate that before you dive in something more complicated and expensive.

Which dealership? Did you check the fuel filter before you took it in?
what about the spin on Allison filter?

it could possibly do something like that if they are tying it into the data line somehow. grounding it with a module ground, or tapping power from a module. but seems kinda unlikely to me.

Which dealership? Did you check the fuel filter before you took it in?
what about the spin on Allison filter?

I don't know what to check - and no I didn't. The tech did put a fuel pressure gage on and showed a vacuum (?) that was in the 9-10 range, and he said the range should be 2-1. He replaced the filter and showed me the new gage reading (1.5) and the problem is gone.

The AUX input module must connect to the data line, as it gets control inputs from the steering wheel controls.

Did that solve the problem or do you still have it?
9-10 is pretty much clogged! I bought Kennedys gauge so I can check my own.

What dealer?

Did that solve the problem or do you still have it?
9-10 is pretty much clogged! I bought Kennedys gauge so I can check my own.

What dealer?

Neil Sandler - on Broad street in Murfreesboro. My driveability problem is solved, but I still havent' tried to plug in the AUX module to see if it causes problems again.