My girlfriend has a 1997 Ford Taurus, 80K miles. Since buying it slightly
used in 1998, she has paid several hundred dollars per year to make the
SERVICE ENGINE SOON light (aka the PAY MECHANIC NOW light) go away, which
lights up at least once or twice a year. Rarely has the car exhibited
tangible symptoms of a problem-i.e., dying on the road, unusual sounds or
behavior, etc. But it sure seems think it's sick a lot.
Unfortunately, Arizona MVD no longer cares about the actual emissions from a
vehicle; they care about lights. If your SERVICE ENGINE SOON light is on,
you fail, regardless of whether the reason has to do with emissions.
(Perhaps all states have the same rule now.) Therefore, she's had to pay
whatever price necessary to make the light go away in order to get her
The latest problem seems to be threefold: bad gas gage sensor, bad throttle
position sensor, and bad "accident" sensor. Repair cost will be $500. (As
for the gas sensor, my girlfriend indeed said her gas gage wasn't working
properly. I don't know about the TPS other than that her car has been
driving fine. The "accident" sensor is allegedly something that'll shut
down the car if it gets in an accident. Anyone know about this? I don't
have too many details, as I didn't talk to the mechanic personally.)
Now, as in the past, the problems are usually attributed to sensors. So,
does this mean that problems are usually electronic rather than mechanical?
When a sensor senses a problem it could just mean that the sensor itself is
malfunctioning, right? (Hope my questions make sense.)
I'm wondering whether all these problems are the symptoms rather than the
cause. Could an electrical short just be causing various sensors to fail
quite often? If so, is the OBD2 diagnostic not sophisticated enough to see
the cause behind the symptom?
I understand that cars age and you must pour money into them. However, my
1996 Saturn station wagon has had twice the miles and half the problems of
my girlfriend's 1997 Taurus. She really wants to dump the thing. Are
Tauruses of that generation just lemons?
>> light (aka the PAY MECHANIC NOW light) go away, which lights up at least once
or >> twice a year.
Judging from your wealth of questions re: basic automotive
mechanical/electrical troubleshooting it seems you and your girlfriend
don't have much of a choice but to continue paying the mechanics to fix
your car, if you are not comfortable driving around with the light on.
If you don't want to fix your cars that's what a mechanic is for, and
why their services are valued.
Otherwise, at least try asking the mechanic to write down the codes for
you, "for reference". If he won't do it, go to an Autozone and get
them to report them for free. You can post them here if you want to
solicit opinions and maybe ways to fix the problems, which seems the
My wife's 2000 Taurus wagon had the light on for about six months, but
I figured it was for a bad DPFE sensor. Code was P0401. I spent $100
on a code reader for ODBII to hook up to a PC. You will easily part
with this much $$$ for a mechanic to just to touch your car.
Googling the code above produced a wealth of information regarding the
high failure rate of these sensors on many Ford models/years. I took a
chance and for $30 I replaced the sensor. No more light.
I am assuming that the "accident sensor" which you are talking about is the
inertia switch. Its purpose is to cut power to the gas pump in case of
collision, so your friend won't perish in a ball of fire from a ruptured
fuel line. These are quite sensitive, and for a good reason. If your friend
is in the habit of hitting curbs or driving over speed bumps at excessive
speed, the switch may trip. The good news is that there is no need to 'pay
the mechanic' in order to reset it. All it takes is pushing a button, and
the user's manual (which your friend is well advised to read) tells exactly
where to find it. If the switch keeps tripping for no reason at all, it's
worth taking a look if it's still solidly attached and not rattling around,
or perhaps accidentally being hit by something, before replacing it. Anyway,
it's an easy to replace and very inexpensive item (around $15).
I have never seen one of those fail on my cars, but the TPS is an
electro-mechanical device, which moves all the time, and ultimately wears
down. It's a farily inexpensive (around $50) and easy to replace item. If
your mechanic diagnosed its failure correctly, it's well worth replacing, or
your friend will experience drivability problems or poor idling, sooner or
later. Unless the wire harnesses or connectors have been abused by someone
who does not know what they are doing, it's very unusual to have a short
mimicking for a TPS failure.
A fuel gauge malfunction won't set the MIL ("Service Engine Soon"). The
failure might be of the sender (in the fuel tank) or of the gauge itself.
Either costs around $60. Judging by the overall $500 quote that you
mentioned, it sounds like the gas tank is coming off. Or perhaps, that it's
time for a second opinion...
The computerized self-diagnostic capabilities are quite powerful and getting
better all the time. A brand new vehicle will be smarter than your friend's
1997 model. Nevertheless, there is a limit to how far a computer can
diagnose, factoring cost into the mix. Typically it will point to a symptom
or a subsystem, leaving the exact defective component to be determined by
someone who understands how things work and is equipped with the proper
tools. In the grand scheme of things, that's a lot cheaper than building all
those tools and diagnostic intelligence right into the vehicle. Things would
look a lot different if your friend's Taurus was flying in outer space,
where a service call requires a space shuttle flight...
No way to comment on your generic complaint that this car is a lemon,
because of the frequent 'check engine light' incidents, as you gave no
details. One or two of them might have been as simple as a loose gas cap
(did I mention reading the manual yet?)
Your state, just like mine, is using the built-in OBDII monitors instead of
measuring actual emissions from the tailpipe. In my opinion, it's a good
policy. Though the vehicle cannot really measures its own emissions, it's
doing a great job of identifying problems that CAUSE increased emissions.
Reading the status monitors stored in your engine's computer is a lot
faster, cheaper and more accurate than exercising your car on a dynamometer
through a variety of simulated driving conditions. And the abundance of AWD
vehicles would require an expensive four-wheel synchronized dymo to even run
Here's an update. Paraphrased from the receipts:
Repairs done 11-04:
Dianostic and labor: $200
P0460 Fuel level Sens Circuit: $93
As for the question of the gas tank-yes, they said they had to remove it to
do the work. As for the inertia switch, it seems that was a phantom-the
mechanic thought that was part of the problem initially but later conceded
it wasn't. After these repairs, the SERVICE ENGINE SOON light came on again
two days later. We took the car back today, and repairs were as follows:
Repairs done 11-09:
P1120 TP sens out of range low
P1125 TP sen circuit intermittent
The mechanic said this still might not be the end of it. If the light comes
on again, he suggests we have the PCM replaced to the tune of $300.
Yes, it is good advice that my girlfriend read her manual. But between her
job, volunteer work, and hobbies, she has little time to become car-savvy.
She's something of a girly girl too. I try to help her when I can, with my
limited knowledge, but my own job sends me out of town for long periods. We
do have both the owner's manual and a Haynes manual, and I'll be reading up
on them. I'm tempted to buy that $100 code reader too. Thanks for the
Neither of those are major problems, and I wouldnt say they are
indicative of bad design.. the TPS is a wear part and fairly common
Bad part is that you might have easily done that fix yourself. Same with
the crash/intertia fuel cut-off., if it comes to that.
First thing to do is either get the readout tool and learn to use it, or
get codes read at autozone or other store that does it free....
then come on here.
Sometimes the car will be just fine until you can figure out what to do,
other times it's imperative to fix the problem ASAP
Yeh, I'm a Krusty old Geezer, staving off dementia here..DEAL with it!
I've never had a TPS fail. In fact no one in my family has (bunches of
Fords, lots of years, many many miles). However, mechanics often replace
them because almost any other failure that causes a performance problem will
also set the TPS error code as well. The Ford Diagnostic procedures indicate
that you should repair all other problems and clear all codes before
replacing the TPS. Few mechanics do this. In their defense, TPS are cheap
and easy to replace. It makes a lot more sense to replace one if the code
is set, than to clear all the other codes, only to have the Customer come
back a couple of days later becasue the TPS really was bad (in addition to
all the other problems).
I have no clue what 'mechanics often do' with the TPS, as I am not one of
However, The P1120 and P1125 that the OP listed indicate voltage falling out
of the normal range of the TPS wiper travel. This is purely electrical --
could be corroded connectors, frayed wires, or even defective PCM, but
definitely a malfunction of the TPS circuit, not some other failure 'also'
setting the TPS code.
that causes a performance problem >will also set the TPS error code as well.
The Ford Diagnostic procedures indicate
Today I had my girlfriend take my car to work so that I could take a look
under the hood of her Taurus, do some basic hose and fluid checks, and
familiarize myself with the location of the TPS that the mechanic had
replaced. I found something disturbing. The coolant reservoir was dry save
for perhaps a quarter inch of fluid at the tapered bottom. I regret that
neither my girlfriend nor I had checked the coolant level before taking the
vehichle to the mechanic. (Flame us if you wish!)
Could the lack of coolant have anything to do with the original "SERVICE
ENGINE SOON" issue? Could they have drained it and forgot to refill it?
I called the mechanic and asked about the lack of coolant. He said he had
never checked the coolant level, and that it would have nothing to do with
any of the OBD2 codes.
I was under the impression that when mechanics are dealing with undiagnosed
problems they generally check some basic fluid levels and hoses, just like I
do with my own Saturn. Is this not the case?
I'll add some coolant and see if it holds. The hoses look good and there
appear to be no leaks elsewhere.
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