[vijaycool]

Originally Posted by chandrda

I bought a Palio 1.6 GTX in 2010 with 29K Odo. I bargained based on the tyre wear, suspension and other conditions. I never gave importance to the owner's claim for 29K on odo and I took 3 months to know the car and fix any issues. Now it runs like a dream.

Regards

Palio registers odo reading in the ecu too. Think in 2001 they have done it but the meter is electro mechanical type. Use a obd 2 tool you can read the odometer from the ecu.

[anoop_lamba]

Vehicles with Digital Odo have an electronic speed sensor generally mounted on the output shaft of the transmission.
The sensor sends a specific number of voltage pulses per revolution of the shaft (e.g. 8 pulses/revolution). These are picked up and processes by the micro-controller inside the instrument cluster.
The frequency of the pulses gives the vehicle speed and the total count of pulses gives the distance traveled.
Even in the reverse gear, cluster counts pulses to add kms to odo reading.

Regarding the odo reading:
- Odo reading cant be altered mechanically or by simple electrical means
- If sensor is disconnected, ECU and other controller which need speed info will not get the info and vehicle will not function properly
- If Instrument Cluster connectoer is disconnected, it may affect other controllers with which cluster exchanges various data/signals (modern day cars have Cluster on CAN)
- Cluster odo reading can be altered by resetting the microcontroller software. Generally this can be done only by Cluster suppliers and not even OEMs
- One more way could be to change software so that it runs slower (changing speedo ratio of the cluster). This will lead to lower speedo indications alongwith lower odo readings. But again this can generally be done only at supplier end who can flash the software.
- If the cluster as a whole is replaced, you get the reading you want

[sa_kiran]

There is an articled about tampering odometers in December edition of FIA's INMOTION. As believed, tampering is a very easy job, even in high end cars.

A few days ago, we were furiously discussing the possibility of tampering on Q7 joyride thread. A few members were of the opinion that it is impossible to tamper. Well, what is impossible is to detect tampering!

[amit_purohit20]

Agree to the above news but in India even if we find a few people carrying out this work of flashing the software but the quantity of people carrying out this task and the cars affected would not be much. But can't say about totally fitting a new or less used electronic meter. But anyway if I were to buy a second hand vehicle I would trust the electronic meter more than the older odometers.

[carboy]

Originally Posted by anoop_lamba

- Cluster odo reading can be altered by resetting the microcontroller software. Generally this can be done only by Cluster suppliers and not even OEMs

What's the technical reason this can be done only be Cluster Suppliers?

Originally Posted by anoop_lamba

- One more way could be to change software so that it runs slower (changing
speedo ratio of the cluster). This will lead to lower speedo indications alongwith lower odo readings. But again this can generally be done only at supplier end who can flash the software.

What's the technical reason this only be done at supplier end?

[anoop_lamba]

Originally Posted by carboy

What's the technical reason this can be done only be Cluster Suppliers?

What's the technical reason this only be done at supplier end?

There is no technical reason behind it.
If someone has the software to be flashed and knows how to do it, he can do it anywhere.

There is a large number of OEMs having larger number of vehicles using even larger number of speedo micrcontrollers. Each having almost unique software. If the hardware itself is not changed, it would be very difficult for frauds to come up with so many "fraud solutions".

As speedo/odo resetting or any other alteration is not done at OEM service centers so generally cluster suppliers do not even share the software with OEMs. Even if they do , it is only for info. Clusters are proprietary designs of the suppliers and mostly OEMs are interested in interfacing it to other relevant vehicle electricals.

[carboy]

Originally Posted by anoop_lamba

There is no technical reason behind it.
If someone has the software to be flashed and knows how to do it, he can do it anywhere.

There is a large number of OEMs having larger number of vehicles using even larger number of speedo micrcontrollers. Each having almost unique software. If the hardware itself is not changed, it would be very difficult for frauds to come up with so many "fraud solutions".

As speedo/odo resetting or any other alteration is not done at OEM service centers so generally cluster suppliers do not even share the software with OEMs. Even if they do , it is only for info. Clusters are proprietary designs of the suppliers and mostly OEMs are interested in interfacing it to other relevant vehicle electricals.

Any software can be cracked even if you do not possess the official version. If Microsoft with all it's resources isn't able to prevent it software from being reverse engineered, I doubt if the guy making the meter software will be able to.