2000 Dodge Intrepid with 3.2 liter engine. On starting yesterday,
speedometer stayed at 0 and transmission, after starting in first gear, went
to second at a few mph and locked there. Engine light also came on. Based
on searching this group it sounded like speed sensors. Local shop indicated
computer showing codes P0700, Transmission circuit failure, and P0731, Ratio
Error - Input doesn't match output. Based on that info they replaced both
input and output speed sensors and reset the error codes. Got the
speedometer working but still goes to second after a few seconds of driving
and locks there. Unfortunately, no engine light and no error code (engine
light does come on briefly when starting as usual). Sitting idle
immediately after starting, I can go to "auto stick" mode and shift back and
forth through first, second, and third but still jumps to 2nd after a few
seconds of driving. Any ideas where to go next? Car not worth spending
I asked the shop the same question and they said it was unnecessary to
disconnect the battery since the device they used to read the codes was also
capable of resetting the computer. Possible or am I being given a line of
....? I'm fairly sure the battery was never disconnected since the time was
still correct and all the radio stations I had entered were still there.
Thanks. Engine light finally came back on and shop found input speed sensor
connection to transmission control module corroded. Repaired and back to
normal. Perhaps that's what killed the speed sensor in the first place.
This does not make sense to me since you indicated the speedometer stopped
working when the transmission went into limp mode (2nd gear). This would
indicate the output speed sensor (which measures the RPM of the drive shaft
to the front wheels) was at fault and not the input sensor (which measures
the engine RPM into the transmission).
From your description (originally no speedometer, then had speedometer, but
wouldn't shift), I'd suspect that they most likely damaged the input sensor
connector when they replaced that sensor. If the facts you conveyed are
accurate, then the only other alternative here is that the output sensor
failed and then the connector failed too shortly thereafter and before the
two sensors were replaced. This seems like a real stretch to me ... they
almost certainly caused this poor connection when they removed/reconnected
In any event, I'm glad to hear you have resolved the issue.
While I agree that actions of the shop probably caused the 'cascade' from
one failure to two, I think a lot of times just the fact that ANYONE, no
matter how capable, getting in there and disturbing things to look, test,
and repair, can cause some secondary failures to come to the surface.
I wouldn't be upset with the shop.
if they replaced both i hope they used factory parts
if the pcm stores the code and the trans store the code and were not cleared in
both modules then there is a good chance the issue will continue
Not true at all, Don't you know what a good trip is? If the check engine
lite is on and you fix the problem, depending on what the fault code is for,
it will be cleared on 2 or 3 good trips as long as the problem is fixed. A
fault code stored WILL NOT make the problem continue (unless the problem is
not fixed). The best way to determine if the problem is fixed is by letting
the controller make the decision. Doing a battery disconnect or erasing the
data on the PCM is not a good idea at all.
Why not? If the code doesn't come back, then you're good to go. Plus
on certain repair jobs, the computer needs to be kicked into a parameter
relearn rather than running on the old settings based on defective
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
If the transmission is in limp in mode and the speed sensor corrected the
problem the PCM will see this. If your gonna clear the codes to see if the
problem returns, why not leave the code there to see if the good trip clears
it? If a sensor fixed a problem the lite will go out. Why clear out all the
monitors and fuel adaptives? If you have a cylinder misfire and replace the
plugs/ wires and then clear the misfire monitor you wont know if the
problem is fixed until the monitor will run. If you replace a plug wire/plug
and don't clear out the monitor the fault code will return when you drive it
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