[Yiros]

Hey guys and gals,

As the title suggests, I managed to get my replacement odo (that I purchased from MKIVSupra) to read the same as I my original odo. Luckily the replacement odo had less km on it so in theory I thought it would be easy to wind the numbers up to match.

Here is a description of what I did to get it to work. In the end it took about 5 hours.

First attempt:

All I need is a 12V wire, a Ground wire and a Signal wire. According to the US Instrument Panel wiring diagram 2 of 2, Red was 12V (pin 8) and Brown was Ground (pin 9). I checked the car and all was good. At this point in time, I thought it was way too easy. I proceeded to try supplying 12V and Ground to the odo but nothing happened.

Second attempt:

I then tired to connect the signal generator direct to the back of the odo (pin 5) while it was connected to the wiring loom. I was watching the amplitude of the signal and for some reason the amplitude was dropping as soon as I would use a common ground.

Third attempt:

The next thing I tried to do was connect the signal generator directly to the speed sensor wiring loom on the gearbox. I jacked the car up on one side and slide underneath and wired up the signal generator. This didn’t work and I was starting to feel a little dejected.

Fourth attempt:

I was considering using my old speed sensor and rigging up a high speed electric motor (around 38,000 rpm) from my competition spec F1 RC car. This seemed like too much effort as I would need to get some adapter shafts made up.

Fifth attempt;

I decided to revisit my first attempt. There are 6 wires connected to the odo. I decided to make 6 test wires up. Each wire had a small terminal on the end and I used some electrical tape to prevent any short circuits (see photo below). I then connected the 12V and Ground wires (pins 8 & 9), then connected the pink ECU wire (pin 6) but this had no effect. I then tried the yellow wire (pin 1) which was another power source. The odo was now on. I then connected the signal generator to the odo. The tripmeter slowly but surely started to increased. The fastest signal I could send through was around 3,000Hz. At this rate it took around 20 seconds to add 10km to the odo.

Sorry for the long thread but you can probably understand how happy I was considering how much time I spent.

Cheers

[PK]

yiros, on Feb 4 2006, 04:02 PM, said:

Hey guys and gals,

As the title suggests, I managed to get my replacement odo (that I purchased from MKIVSupra) to read the same as I my original odo. Luckily the replacement odo had less km on it so in theory I thought it would be easy to wind the numbers up to match.

Here is a description of what I did to get it to work. In the end it took about 5 hours.

First attempt:

All I need is a 12V wire, a Ground wire and a Signal wire. According to the US Instrument Panel wiring diagram 2 of 2, Red was 12V (pin 8) and Brown was Ground (pin 9). I checked the car and all was good. At this point in time, I thought it was way too easy. I proceeded to try supplying 12V and Ground to the odo but nothing happened.

Second attempt:

I then tired to connect the signal generator direct to the back of the odo (pin 5) while it was connected to the wiring loom. I was watching the amplitude of the signal and for some reason the amplitude was dropping as soon as I would use a common ground.

Third attempt:

The next thing I tried to do was connect the signal generator directly to the speed sensor wiring loom on the gearbox. I jacked the car up on one side and slide underneath and wired up the signal generator. This didn’t work and I was starting to feel a little dejected.

Fourth attempt:

I was considering using my old speed sensor and rigging up a high speed electric motor (around 38,000 rpm) from my competition spec F1 RC car. This seemed like too much effort as I would need to get some adapter shafts made up.

Fifth attempt;

I decided to revisit my first attempt. There are 6 wires connected to the odo. I decided to make 6 test wires up. Each wire had a small terminal on the end and I used some electrical tape to prevent any short circuits (see photo below). I then connected the 12V and Ground wires (pins 8 & 9), then connected the pink ECU wire (pin 6) but this had no effect. I then tried the yellow wire (pin 1) which was another power source. The odo was now on. I then connected the signal generator to the odo. The tripmeter slowly but surely started to increased. The fastest signal I could send through was around 3,000Hz. At this rate it took around 20 seconds to add 10km to the odo.

Sorry for the long thread but you can probably understand how happy I was considering how much time I spent.

Cheers
<{POST_SNAPBACK}>

:lol:

Can you reverse it??

:lol:

PK

[Boost Samurai]

Good work My Yiros!

Once you make the process portable I wouldn't mind winding my odo UP to the correct reading (i.e. old odo + new odo)

[Yiros]

PK2811, on Feb 4 2006, 07:14 PM, said:

:lol:

Can you reverse it??

:lol:

PK
<{POST_SNAPBACK}>

Don't know. It was hard enough getting the thing to go up.
I am guessing I could always wind it up to 999,999 and let it tick over back to 0....

SupraPolak, on Feb 4 2006, 07:57 PM, said:

Good work My Yiros!

Once you make the process portable I wouldn't mind winding my odo UP to the correct reading (i.e. old odo + new odo)
<{POST_SNAPBACK}>

No worries Pres. I will rig up a 240V - 12V DC transformer/rectifier. The only problem is it may take a while as you can only wind it up so fast. I am more than happy to come around and set it up for you. We can estimate how long it would take and let it run for a day or so. I am also considering a 555 timer circuit. We will see how it goes…

[Yiros]

Hey Pres, I finally have a 12V DC power supply. Let me know when you want to do this.

It will take some time so we will need to set it up and leave it. If you want, you can borrow my old odo while we are updating your current odo (not sure if you will experience limp mode - Viagra will fix that :lol:

[Darren]

Viagra in the Petrol tank makes your Supra GO HARD :sex: :burnout:

[Boost Samurai]

"Limp mode", you guys haven't been talking to my wife behind my back again, have you? :D :P

How's this Saturday sound?

[Yiros]

Saturday is fine. PM your address and mobile number so we can organise a time.