A Ford Freestyle Tranny Issue
Robo Tech was called for a customer with a 2005 Ford Freestyle withn 90% of the miles
driven on highway . The vehicle was garage kept and dealer serviced, according to the
customer.
This vehicle was equipped with a CVT or continuously variable transmission.
CVTs are fairly new on the technology plane.
They were developed in the 70s, but are now becoming mainstream.
Fords CVT are made in the US in Batavia, Ohio.
Production started about 2005 originally via joint venture with ZF Friedchshafen that goes
back about a few years.
That makes Ford the sole maker of the CVT known as the CFT30 found in the Freestyle,
Five Hundred and Montego.
Multiple manufacturing delays caused the project at Ford to be delayed.
The problem with the CVT is as engines produce more power and torque, that is where the problems
arise.
At present the 3.0 liter produces 207 pounds of torque.
The 3.5 liter produces 250 pounds of torque.
The current CVT can not handle an increase in torque and is made to operate under 258
pounds feet of torque.
Anything approaching that number would be operating at its max and therfore not conducive
to longevity.
Does that mean Ford can't make a CVT to handle the torque, yes they can, but that brings
on a whole set of other considerations including additional expense, weight, the current CVT
weighs about 70 pounds, more than an auto tranny.
Ford has had problems with the CVT and they believe their new 6 speed Auto tranny joint
venture with GM is the way forward.
So their CVTs are on hold for now.
The Nissan Murano is probably one of the better known CVT operated vehicles, but it also is
not without problems, as Robo Tech has said on other stories from the road.
The shops said the "wrench light" indicating a problem with the transmission started coming
on sporadically.
When it came on, you get no acceleration and sudden jerks.
The customer had taken the vehicle back to the dealership 4 times, each time they say
it's fixed, but each time the same thing happens.
There are many reports of these CVTs blowing a hole on the case and parts popping out.
But I was determined to solve this case.
As soon as I started the diagnostics I was faced with a code P2765, Input/Turbine Speed
Sensor "B" Circuit.
Dealer had said the mechatronics, also known as valvebody was bad.
In this vehicle the turbine speed sensor in part of the valve body.
From experience I knew better than just replace the part.
I continued the diagnostics with the trusty oscilloscope.
Tapping at the sensor wiring on the transmission computer.
I decided to raise the vehicle, disable traction control and drive.
The output signal looked good, with a nice square wave.
I knew that no sensor test is complete until the system is stressed.
So I lowered the vehicle and went out for a road test.
As soon as I hit a few pot holes I saw it.
A faulty Hall-Effect Signal was evident.
Ok, but was it a sensor or a wiring issue?
I decided to follow the wiring harness, especially arounf the engine compartment using the fox
and hound device, when all of a sudden found the wiring harness getting rubbed through.
I checked the harness and found the protective loom rubbed through in one spot and light
damage to the wires.
Taped it up and moved it away from the rubbing source.
This case is the perfect scenario for a vehicle with a new technology, as in the CVT transmission,
with all sorts of criticism for it and the not ending up being a normal repair.
Not all sources of problems can be blamed on faulty design, and the technician should
always keep an open mind during diagnostics.