Thread: Reprogram of TD5 speedo

Looks like he made hard work of solving a problem that has a simple solution already.

.... especially that it's about a Defender while AFAIK here is the Disco 2 section

RTT,

You'd have to check if the D2 instrument pack uses the same firmware//eeprom settings, but it would be a nice modification if it translated across.

The VSS signal is also used by the ECU for various things and needs to be corrected.

That can be done quite simply by altering the pulses per mile scalar in the engine map, although you'd need to alter for every tune//remap you used and it would require replacing the chip on a MSB ECU.

cheers
Paul

IMO the Defender speedo works in a different way than the D2's, the VSS is analog 12-0V signal which alternates 6 times/wheel rotatio coming from the mechanical transducer and filtered by a buffer within the IP while on the D2 is digital 8000 pulse/mile signal delivered by the SLABS ECU.

Originally Posted by sierrafery

IMO the Defender speedo works in a different way than the D2's, the VSS is analog 12-0V signal which alternates 6 times/wheel rotatio coming from the mechanical transducer and filtered by a buffer within the IP while on the D2 is digital 8000 pulse/mile signal delivered by the SLABS ECU.

Fery,

Don't lose sight of the fact we are dealing with microcontrollers and sensors, not just electrical interfaces between devices.

The pulses are converted into numerical representations, and the post RRT linked to is showing how to adjust the scaling of the pulse count to correct for tyre size.

If the instruments are manufactured by the same company it's likely that the code will be very similar.

cheers
Paul

Obviously a bloke who enjoys a challenge or has way too much time on his hands His existing (as opposed to original) VDO electronic speedo is a great piece of kit, accurate, easily configurable and re configurable to suit different wheel/tyre combos. It's downfall is that the plug in incandescent lamp eventually frys the display. Use a LED lamp instead and it'll last forever.

I've got one in the Oka replacing the original '90's VDO setup which has a dead simple VB Commodore Hall Effect 'transducer' and it's a five minute job to re calibrate with tyre/wheel changes especially if you've got a measured 1Km to work with.

Deano