Posted to Technical Tips Forum on 12/1/2013
Hard to find electrical problems
I think one of the most important things NOT to do is move
the wire harness when trying to verify the customers
I am working on a 2006 escape 2.3 auto 4x4 with 60,000
Step one, recreate customers issue.
Step two, find the problem.
Step three fix the problem.
Step four, make out the bill.
The concern was reverse that would engage and disengage and
a speedometer that at times would hang at 20 or 40 mph.
I got in the car with the scanner plugged in, put it in
reverse to back out of the parking spot, as the accelerator
pedal was touched it quickly disengaged and engaged the
trans abruptly. My first thought was a broken or loose MLPS
connector. I had one code p0707 I think.
The in and out of reverse was very very quick and harsh, so
I was very careful moving it. I brought it in the shop to
have a look at the connector and sensor. Nothing I saw
looked bad or out of place, except the new MLPS.
I knew I was the third person to look at it for this
concern. Now I have looked at the scan data for the mlps as
I gently moved the connector and wire harness. Nothing shows
up at all, remember I have tried not to MOVE anything
without knowing that I did.
Next I try reverse and it works perfectly, no disengagement
or speedometer issue. Now what did I do to change the
problem? I don't know.
Now I walk away for a bit. When I come back I put my scanner
pid on just the mlps voltage in graph form, move the harness
and low and behold I have a zero volts on the graph for just
one recording frame. The mlps must have a bad connection. No
dice, everything is perfect. I start a new graph and realize
that as careful as I am, my left elbow is moving the harness
at the back side of the cylinder head.
Now I can recreate the problem with a gentle push on the
wire harness that is 18 inches from the sensor. I found it,
2006 Ford Escape XLT, Transmission Photo 2006 Ford
Escape XLT, Transmission Photo 2006 Ford Escape XLT,
The learning curve is steep with electrical issues. Be very
easy when moving something when trying to recreate the
issue. Going at it, without knowing what you are changing
always ends with, [can not duplicate customer concern].
Never good as the customer is looking at you thinking it
does it every day for me.
Take your time and be very diligent with respect to knowing
what you are touching.
Dan from Wisconsin
12 Replies Received
12 Replies Received