|
Jim Grant's Tech Tips
Ford Aerostar, Bad Cam Sensor?
Q:
I have a Ford Aerostar van with a V6. We were on a trip when our check
engine light came on. I took it to Auto Zone to get it checked on their
computer. The code that came up was P0340 and they told me it was the
camshaft sensor. I bought one and installed it. The old one was melted.
I put the new one in, turned the van on and the light was off. I ran the
van for a few minutes, turned it off and restarted it, the light turned
on. I took the negative side of the battery off and reset the light. I
drove it for about 5 miles came home, turned it off, turned it back on
and the light was back again. I took it back to Auto Zone once again to
check it with their computer. The same code appeared. They reset the light
and again it came back on. I took it back and again and same code. They
installed a new camshaft position sensor, thinking that it was a bad part
they sold me. I drove it, and again the light came back. The code that
keeps showing is for the camshaft sensor. What else could it be? I'm going
nuts here... Dave
A:
The computer in your
vehicle, as with many, will turn the warning light on if it fails to see
a signal from the camshaft position sensor or, if the signal is not in
phase with the crankshaft position sensor. The computer expects to see
a signal from the cam sensor that coincides with information that is sees
from the crankshaft position sensor. If the signals dont match up
right, then the computer gets upset and turns the warning light on. What
Im really curious about is how or why did the camshaft signal sensor
melt? If it melted, what happened to the connector for the sensor? Is
there a chance that there is a broken or damaged wire? If the wires are
okay then the signal to the computer has to be checked. Most aftermarket
computer scan tools have a problem reporting this information. You may
have to find a shop that has a lab scope or a scan tool with OEM compatible
software to get to the bottom of the problem.
|
|