Inaccurate Speedo Reading Fix

[Snooozy]

if the LED is not flashing when in drive then the unit is not getting the signal from the transducer.
I would double check the input wire you are using

[Hornet75]

I know I'm getting a signal to the wiring that comes out of the little box, as when I removed the module and connected the two wires together my speedo returned to normal.
Got a feeling it's a faulty module.
Going to check it out again tomorrow. Hopefully I won't do my head in lol.

[Hornet75]

Well just checked the power input, 12v though the unit is only putting out 6v.
Is this correct? Have checked all connections and they are fine.
I thought I saw the LED flash once though hasn't done it again.
Getting frustrated that's for sure

[Snooozy]

I am not sure about the voltage of the sensor input. the unit has 12v input but the signal wire may have a low voltage.

most chips run on 5v, so it may be correct.

would need to have someone pull the dash apart to check voltage at various places in the circuit. Unfortunately I am not able to do this anytime soon.

[Hornet75]

That's ok Snooozy
I think the guy across the road is good with electronics. If he is, I will get him to check out the circuit board and what not.
Plus another set of eye's may solve the issue.
Putting it in the too hard basket at this stage.
Thanks for the help so far

[Snooozy]

no problems hornet, hope you can get it sorted soon.

[Hornet75]

Snooozy, when you did the original setup to calibrate the unit, did you have S1 set to 2 and S2 set to A?
I got a replacement unit from Jaycar and double checked all the wiring.
Still can't get the LED to flash

[Cowboy Dave]

Pretty sure Snooozy is on the road doing a trip at the moment mate. He may still reply but don't be too surprised if it takes him a while.

[Hornet75]

Thanks for the heads up Cowboy Dave.
Will keep using my Ultragauge
Cheers
Bill

[Snooozy]

Snooozy, when you did the original setup to calibrate the unit, did you have S1 set to 2 and S2 set to A?
I got a replacement unit from Jaycar and double checked all the wiring.
Still can't get the LED to flash

to tell the truth, I have no idea as it was so long ago.

as Cd said, I am on the road atm & will not be home till the 10th of July.

drop me a PM as a reminder & I will dig out the instructions when I get back. Hopefully I can give you an answer then

[thsmoker]

Has Anyone got theses things to work yet? Iv tried everything!!!!

[Snooozy]

Has Anyone got theses things to work yet? Iv tried everything!!!!

mines been working perfectly for years now

[thsmoker]

Has Anyone got theses things to work yet? Iv tried everything!!!!

mines been working perfectly for years now

Yes it seems you are the only person to get one to work on a triton, in the whole world!!!

Iv search every inch of the internet!!!!!

[RHKTriton]

Well....after getting his oversize donuts, my son lashed out for the DigiTech speedo corrector module from Jaycar. Seems to be a commercialised product based on the Silicon Chip kit.

So the task - install the sucker, set the switches and send him on his way. After reading Snooozy's installation I thought this was going to be a walk in the park.

Decided intercepting the signal wire at the console would grab it before the speedo & RV meter, however I couldn't achieve continuity between the sensor W-L wire and the one inside. Much searching found a junction plug (c127) near the front of the console, where the signal is split off to speedo, RV amongst a couple of other destinations.

After many switch combinations, we have simply not been able to get to the stage of detecting a sensor output.

Suspecting the auto sensor detection isn't working.

How have others progressed?

[coughy]

hay what car u have??? RHKTriton???

i have a pb challenger and i was going to pick up the speed sensor wire from the auto ecu under the colum at the c45 plug wire 32 B-Y ??
have you looked here?? this is the speed output sensor wire to the ecu and it is easy to get to at the steering wheel colum that is where the ecu is located....

from install manual

- Connect Power (use an ignition-switched source), ground, speedo “input” and speedo “output” (to the speedo)
- Set S1 to 2
- Set S2 to A
- Install link LK2
- Drive the car for a minute (the speedo will not work).
- Observe that the LED flashes at 1Hz when the car is moving. This shows that the module has set itself for the type of speedometer signal that is present and that it is receiving a valid signal.
- If the LED doesn’t flash, install link LK1 (instead of LK2) and try again.
- Set S2 to 0
- Set S1 to 0
- Try the link options LK3, LK4 or LK5 until the speedo works (the speedo should read as it did with the car standard).
- Set S1* and S2** to give the required correction.
* S1 corrects the speedo reading in single units.
** S2 corrects the speedo output in tens.
e.g. If the required correction is 18%, set S1 to ‘8’ and S2 to ‘1’
- If the speedo reading needs to be corrected upwards rather than the default downwards, set S2 to F and then wait for the LED to flash twice. Then set S2 back to its required correction value. To return to downwards speed correction, again set S2 back to F and wait for a single flash acknowledgement.

[RHKTriton]

Yeah its a 2009 glxr coughy.

I tapped into the sensor wire just before it hits the commoning plug, where the signal gets split off to speedo, Rev meter, etc.

After studying the Silicon Chip cct, I'm going to try it, manually set with the pull-up resistor. The symptom seems to indicate that the sensor transistor isn't getting a voltage to pull down and hence allow it to generate pulses.

The instructions supplied with the module are very lean.

[x-ray]

Has anybody got a speedo corrector from Jaycar to work on a MN, I've tried 2 different kits and still can't get it to work. My speedo is out by 10kms and it's doin my head in. I need help!

[RHKTriton]

Hello X-ray; I haven't had a chance to do more on my son's kit, but I left it concluding that the kit's drive to the gearbox speed sensor unit is insufficient to fire it up.

My next strategy was to leave as much of the OEM circuitry working and only intercept the feed to the actual speedo input. The key seems to be leaving the vehicle to supply power to the sensor and just look for pulses after this.

There is presumably a manual mode that the speed corrector can be started in that may work better.

[x-ray]

Hey RHK Triton, I'm giving the Jaycar thing a miss. I've found an Aussie company that makes a unit that runs off the speed sensor, as I tried to run the Jaycar one off the speed sensor and off the back of the speedo and I couldn't get it to work. The one I'm gonna try is called Yellow Box and at $95us it better bloody work or I'll be taking to it with a FBH!
https://yellr.com/

[Zwagerman9]

I attempted the Jaycar module on my old 2wd Hilux and it would not work. I did manage to buy a SpeedoHealer which are for motorcycles and apply the same principle and worked perfectly. I did look into the Yellr box at the time but this seemed easier as I already knew and had spliced the vss wires. Good luck.

[RHKTriton]

The Jaycar corrector just doesn't seem to recognise the pulses from the sensor.

I used to think they simply converted the pulses to an analogue value and use this to set the frequency of a second pulse generator. But the unit actually has a microcontroller chip to generate a new pulse stream from the monitored one.

I will wack a scope on the sensor when I get a chance and see what we actually have to play with.

[Bitsamissing]

I have a near-new GLX+ MQ on 245/70/16s. The vehicle, and the tyres presumably, have 7,000km on them. I checked the speedo and odo against a GPS today.

The speedo over-reads by about 8%. This is pretty crap, but I have owned other cars with similarly inaccurate speedos. On the other hand, my TJ Magna was very accurate - less than 2% over-reading. I know manufacturers always build a bit of over-reading into the speedo, but 8% seems way too excessive.

The odometer however appears to be very accurate. I would need to test it over a longer distance than the 10km I did a couple of times today, but it seemed to be just slightly over-reading - less than 1%.

The other specified tyre size for the MQ is 245/65/17. Mathematically, the diameters of the two wheel sizes are very close, so there shouldn't be any difference between them as far as speedo and odo accuracy goes.

I assume it would be very difficult to devise a way of correcting the speedo reading without affecting the odo reading.

[explorer.dave]

The speedo reading and odometer readings are two different entities, you can fix the speedo with different tyre sizes but not the odometer. 8% is high, I had 4-5% on standard tyres, went to 265/75/16 and 1% at best difference now.

[Bitsamissing]

Are you confusing odo and tacho? In every car I've had anything to do with in the past, the speedo and odometer have both received input from the same sender on the transmission. I'm not sure what else the odometer reading could be based on...