I've got a 99 Trooper with TOD. Winter before last, the 4WD quit working and
the dealer replaced what they called the "control valve". It was under a
cover mounted right on the front center of the front axle/(differential?).
It was covered under warranty. Now, after only being used about 3 times
since, it supposedly failed again. It doesn't work and the "Auto" and rear
wheel lights flash slowly. This time, the dealer and the district customer
service manager say it is not part of the drive train and is not covered
under the 60/60,000 drive train warranty. I've owned the vehicle for 48
months and it has 47,950 miles on it. The mechanic at the dealer told me
that these things hang right out there in the front, exposed to rain/snow
etc. and can easily fail. I wondered about that since it is behind a baffle
and, I think, inside a pretty sturdy outer cover. However, the district
customer service manager says it is highly unusual for this valve to fail
and really unusual for it to fail a second time on the same vehicle. He
asked if the mechanic had done a continuity check. I didn't know, since I
originally thought this valve was a mechanical thing. But the district
customer service manager says it is just a solenoid operated control valve.
He suggested taking it for another opinion to another dealer. I told him
there are no other dealers around so he suggested a GM dealer. We talked
about the fact that the Troopers are made in Japan and I got the impression
that the TOD is a GM design and though parts may not be interchangeable, a
GM trained mechanic should be able to diagnose and even fix it.
Question is, what do folks here know about this? Does anyone have experience
with this valve failing? Or can an electrical connection come loose? If so,
where are the likely places for such connections to have a problem - under
passenger seat, somewhere on the front of the vehicle, etc.? Can GM service
departments at least check the thing out - in other words, even though the
Trooper is made in Japan, is it similar enough to the Rodeo, for example,
that a GM service department would know how to check it and maybe repair it?
If I can't find a mechanic to check it, is there an external electrical
access point where I can do my own continuity check. If not, how and how
difficult is it to open the covers and get at the valve itself for a
continuity check? Is there a gasket that might need replaced? This mechanic
at the local Isuzu dealership was done in about 2 minutes and spent the rest
of about 10 minutes getting the part number and price and writing up a
report form. So I don't think he did much at all. In fact, after I left the
dealership, I noticed he had left the 4WD button depressed and in the
dealership parking lot, I noticed that the 4WD worked perfectly for a while.
After getting on the highway, I turned it off. But then, when I entered the
large, snow covered lot of another group of stores and pressed the 4WD
button again, it did not work again, the green "Auto" light began flashing
slowly and then the red "Check" light came on. That was the first time I've
ever seen that red Check light and I've not been able to find out what it
really means. The book says to stop the vehicle and turn the engine off. It
went out right away when I turned the 4WD switch off. When I turned it off
and the Auto light went out also. The next time I tried to turn it on, the
same thing happened, so I've left it off.
I hate to be paranoid about this or distrust the mechanic or dealership, but
something about it doesn't seem right, particularly after the comments from
the Isuzu customer service guy.
Thanks for any help,
galb accr at earthlink dot net - take out the spaces and convert the at and
dot to the usual for direct contact