How hard is it to disable the Odometer?

[klamathpro]

I've taken a look at quite a few gen1 Vipers and there was one that had around 10k miles but looked like it really had over 50k. How hard is it for someone to mislead with the mileage on these things? Besides the obvious swapping of odometers, does it take great effort to disable the speedo?

 

[SylvanSRT]

you may be able to plug in to the pcm/computer and if that has not been changed or tampered with it will have recorded actualy mileage even if the dash pieces have been changed

 

[2002_Viper_GTS_ACR]

Keep im mind a new PCM will start with zero.

Matter of fact, I used to run 2 different pcms, for a weekend of racing, or drag strip, I would run mopar, for street I would use my oem one. Each one only takes the miles they record, so for a 100 miles i could split them on 2 pcms, and so if you use that as a determinant, its going to be scewed also.

Do a car fax, and if it had to get serviced at dodge, or dmv emissions, its got records, those would be a good indicator if an tampering has occured.

Jon

PS. And with and DEalership ODBII/III device, its easy to reset that counter to zero, or ANY other number to match your current odometer.

 

[Cris]

Yes, the speedo/odo receives a signal from the pcm. interrupt the wire and no signal. A slight cal change will prevent any concerns. Note the PCM odometer recorded is addressable. In other words anyone with a DRB can reset it to what they want.

As an aside anyone who would actually disable their odometer to commit fraud is an **** and should be hung. I have witnessed one that was clearly disconnected (less miles on the odometer at the time than the distance traveled on that given day ) but that car has never been sold.

 

[ucfpete]

i was also wondering the same thing. my odometer would never line up correctly. there was always 1 or 2 numbers that were slightly higher or lower than the rest. so, i took it to a dodge dealer and they told me the pcm and the odometer was the same. they replaced my odometer, but its still doing the same thing!

 

[SSNAKE]

Take a look in your friendly DC manual and you can disconnect the wire. I recall a friend wiring in series a single pole switch that he left under the ashtray ...........

 

[Randy]

Its simple to disable the odometer, but it also disables the speedometer - just reach back under the dash and unplug the connector (there is one cable/connector on the Gen I for the speedo signal to the dash instruments). It does not affect anything else; e.g. the computer doesn't care if that wire is connected.

 

[Randy]

so, i took it to a dodge dealer and they told me the pcm and the odometer was the same. they replaced my odometer, but its still doing the same thing!

Time to find a new dealer, perhaps? At least on a Gen I, the odo and PCM reportedly have no dependancy/relationship. I believe that my local Viper tech once told me that the PCM does *not* record mileage on the Gen I, and instead the PCM supposedly records the amount of time it was turned on (???). The time recorded should bear some general relationship to the mileage; e.g., 10,000 hours on a car with less than 1000 miles on the odo would be an obvious suspicious flag. You could do some calculations to decide if you are suspicious or not; for instance, assume an average overall speed of, say, 30 mph, and 10,000 hours should have 300,000 miles on it. Perhaps 30 mph is too high, perhaps its just right - have to somehow take into account all those times idling and not moving; such as at a light, warming up, whatever, offset by the time spent traveling on highway.

I'd also bet that the Gen II odometer is also unrelated to the PCM, since its mechanical. It could make sense that the PCM finally also records mileage, but I can't imagine that the mechanical odometer in the Gen II dash is in any way showing you the PCM mileage output (if indeed the PCM records it) - the odo, being mechanical, is merely incremented from the speedometer signal.

 

[joe117]

As someone said,
The carfax report on the car is going to have some data points where miles are reported.

If that doesn't look right, someone may have messed with or replaced parts.