Yellowbox Speedometer Correction Install (1 Viewer)

[RoderickGI]

Yeah, I was thinking of sticks and branches thrown up catching it, plus stones thrown up.

I have driven a lot of Australia's outback, often on rocky roads at speed, and the stone damage can be considerable. I have bolt heads under there that may need to be cut off they are so damaged. I've also driven sand where the belly rubs constantly, and where the centre of the track has shrubs, rocks, and such. Some rock crawling, river crossings, deep flooded roads.

So I look for vulnerable bits hanging down. It sounds like you don't have the same concerns, so that position is fine.

 

[trdcorolla]

I just ordered a Yellow Box. In my e-mails to them prior to my order, they said the 2M cable length is now standard. The lead time I was told was 1-4 weeks for my order.

 

[MongooseGA]

Correct, 6' cable is what you'll receive.

I installed my new one about 2 weeks ago. Seems fine thus far. There is a lag in indicated speed vs actual speed for a second, and it will hover above 0 mph on the cluster before dropping to 0 at a stop. IMO, small things outweighed easily by having an accurate reading.

Mine is in a waterproof bag ziptied up near the transfer case, well above the frame rails. As mentioned earlier, if I'm at risk of damaging this unit, then a $40 accessory is the least of my concerns with what I'll actually be needing to fix.

 

[RoderickGI]

You received a reply trdcorolla? You did better than I did. I never got an answer to my email.

It's a shame that custom cable lengths are no longer supplied, but it does look like that option has disappeared from the ordering page.

I think I'll order anyway, as my concern was lag in response, and MongooseGA has answered that. I won't like a second of delay, but if that is all it is, not so bad.

This isn't a $40 accessory though MongooseGA. It's US$110.85, which is AU$161.42, and it is a bit rude for an Aussie company to sell in US dollars to Aussies with the exchange rate at the moment. What a boon for profitability! Maybe I'll ask about an AU$ price before ordering...

 

[MongooseGA]

Yikes! I could have sworn I only paid about $40 for it. I see it's listed at $94 USD here.

If it helps, this is the contact I used to communicate with them:
staff@yellr.com


A girl names Jennifer was manning the account while I was emailing. Full disclosure: while they were very polite, there was tons of delay between messages for me.

 

[trdcorolla]

Yeah, they were responsive to my emails. Reading through the thread it looks like there quite busy for a while. Jennifer was the person I emailed with too. I did notice that some small companies have easy junk criteria, so something in the body of the email or even your email address might sent it straight to their junk mail and they will never see it.

 

[RoderickGI]

Thanks guys. I've sent an email asking about Australian pricing, given the current exchange rate.

Our dollar only buys 68.4 of your cents, so it makes quite a difference!

 

[trdcorolla]

Got my shipping confirmation. Glad to finally have a correct speedo again pretty soon.

 

[RoderickGI]

BTW, I received a reply from Jennifer who said they still do custom length wiring harnesses for the Yellow Box.

I didn't see it on the order form though. I guess once I measure up I shall have to email my requirement.

 

[trdcorolla]

Yellow Box came in today. Installed it. Put in the setting I came up with using the example they gave in the manual. Went for a drive and it was way off. Adjusted it like 5-6 more times to get it to match my gps between 25mph and 50mph on the street (assuming a 1-2 second lag on the speedo side). The initial adjustment and the additional 5-6 adjustments ended up being 15 miles of testing per my GPS, haha. I'll test out some freeway soon.

 

[Eyedaho]

I installed my plug and play Yellow Box in my '99 100 this week, and it's working great. I didn't bother to calculate the offset, but with the +/- pushbuttons it was super easy to dial in. The cable length was perfect to run up through the grommet under the DS floormat and locate the box in the kick panel. I wanted a tight seal in the grommet, so I drilled a hole slightly smaller than the Yellow Box cable housing, pushed the pins out of the connector on the box end using an Amp pin pusher (see pic), and pulled the cable through the grommet hole. I'm slightly ODC, and I didn't want to cut a slit in the grommet.

I also like that the Yellow Box now includes a spare plug with a jumper wire so the Yellow Box can be deleted without having to mess with the cable connections under the truck. Just plug it into the cable end instead of the Yellow Box.

Regarding lag, I don't notice much lag, but by design there has to be some. This box is counting pulses over time, averaging the pulse rate, and then generating a faster/slower pulse rate that's sent on to the truck. There has to be a small lag for it to be able to read the speed sensor pulses over a given time window and then generate the new pulses. I'm sure they've kept that window as short as possible, but it can't be instantaneous. It's not possible with how the electronics work for a speed sensor reading a toothed wheel.

 

[JWick]

I installed my plug and play Yellow Box in my '99 100 this week, and it's working great. I didn't bother to calculate the offset, but with the +/- pushbuttons it was super easy to dial in. The cable length was perfect to run up through the grommet under the DS floormat and locate the box in the kick panel. I wanted a tight seal in the grommet, so I drilled a hole slightly smaller than the Yellow Box cable housing, pushed the pins out of the connector on the box end using an Amp pin pusher (see pic), and pulled the cable through the grommet hole. I'm slightly ODC, and I didn't want to cut a slit in the grommet.
View attachment 2118779
I also like that the Yellow Box now includes a spare plug with a jumper wire so the Yellow Box can be deleted without having to mess with the cable connections under the truck. Just plug it into the cable end instead of the Yellow Box.

Regarding lag, I don't notice much lag, but by design there has to be some. This box is counting pulses over time, averaging the pulse rate, and then generating a faster/slower pulse rate that's sent on to the truck. There has to be a small lag for it to be able to read the speed sensor pulses over a given time window and then generate the new pulses. I'm sure they've kept that window as short as possible, but it can't be instantaneous. It's not possible with how the electronics work for a speed sensor reading a toothed wheel.

@Eyedaho is this the spare plug with jumper you’re referring to? If so, one just needs to unplug the Yellow box and use this in its place and the speedo is back to factory settings?

 

[Eyedaho]

@Eyedaho is this the spare plug with jumper you’re referring to? If so, one just needs to unplug the Yellow box and use this in its place and the speedo is back to factory settings?

Sorry for the slow response. I was guessing that was the case, but I wanted to actually try it to make sure. I plugged that jumper in in place of my Yellowbox tonight on my way to work, and it did in fact bypass the Yellowbox and return my speedometer to factory operation. I'm not sure what the other two wires in that cable are. I'll have check in the EWD when I get a chance, just to satisfy my curiosity.

 

[JWick]

Awesome to hear! Yeah, mine came with 2 of those jumpers and an extra length of cable with splice ready ends.

 

[Bud_Dude]

I have lag. I don't notice it on daily driving but I think it causes the slight throttle surge/release that I get when trying to use cruise control on road trips. It actually makes me nauseous and I'm not the type to get motion sickness.

I've read with great interest everyone's comments about the Yellowbox lag and how it interacts with the cruise control. It makes sense that a closed loop control system would not respond well to having its feedback signal delayed, which is inevitable with the Yellowbox in the loop. Has anyone looked into connecting the Yellowbox to the speedometer directly rather than down at the speed sensor in such a way that the cruise control feedback signal is not affected, but the displayed speed is corrected?

 

[jLB]

I've read with great interest everyone's comments about the Yellowbox lag and how it interacts with the cruise control. It makes sense that a closed loop control system would not respond well to having its feedback signal delayed, which is inevitable with the Yellowbox in the loop. Has anyone looked into connecting the Yellowbox to the speedometer directly rather than down at the speed sensor in such a way that the cruise control feedback signal is not affected, but the displayed speed is corrected?

Yes, and although is seems to go against the grain around here, we've been quite pleased with our install behind the glovebox.

(Yet Another) Speedo correction thread - Do you like yours?

Hello all - I'm not thrilled with the performance of my current speedometer correction device, so figured I'd ask if anyone has found something that works better. The answer may be no, but is worth a shot. I'm running 33" tires on a slightly lifted AHC equiped LX470. I've currently got a...

forum.ih8mud.com

 

[Bud_Dude]

Yes, and although is seems to go against the grain around here, we've been quite pleased with our install behind the glovebox.

Thanks for the quick response, do you know if anyone's done this on a 97 FZJ80? Same wiring interface?

 

[jLB]

Thanks for the quick response, do you know if anyone's done this on a 97 FZJ80? Same wiring interface?

I would expect that the process would be somewhat similar on an 80 series, but (at the moment) I no longer own an 80 series, nor do I have an EWD for a 97 80 series.

I suspect there's someone over in the 80 series section of this forum, that could describe a "behind the glovebox" install of a speed correction device.

 

[MongooseGA]

FWIW, I've never experienced that issue with the cruise control and the yellowbox.

 

[Bud_Dude]

So... Has anyone tried the Dakota Digital SGI-100BT for their speedometer correction project?
SGI-100BT: Universal Speedometer and Tachometer Interface

Dakota Digital Accessories

You’ve purchased Bluetooth-enabled Dakota Digital accessories and want to get the most out them, all with wireless control? The Dakota Digital Accessories App allows you to do just that! When using the SGI-100BT --------------------------- -Speedometer and/or Tachometer input and output...

apps.apple.com

This looks to be a far more advanced unit than the Yellow Box that most folks use and allows calibration adjustment with onboard pushbuttons like the Yellow Box, but also with an IOS (iPhone) or Android device via Bluetooth. Meaning one can install the module behind or under the dash and recalibrate at will without need to actually get to it. It also seems very reasonably priced at around $94 on Amazon...

So I've ordered one of these and will install it in the next week here. In preparation to install it I've studied the signals from the speed sensor and confirmed couple things I've not found documented elsewhere here on IH8Mud... Hopefully others will find it useful.

1. The number of pulses per mile (PPM) from my '97 80 series LC - For this I put the truck up on jack stands and ran the truck for two miles as indicated on the odometer trip meter and recorded a total of 8198 pulses for an average of about 4100 pulses per mile as measured with a Universal Counter.
   
   
   
   
   
2. The nature of the signal into the speedometer as viewed with an oscilloscope - A very clean square wave 11.5V signal with a period of approximately 60mS at an indicated speedometer speed of about 15mph.
   
   
   
   
   
3. For purposes of connecting the unit I'll be cutting the red-orange wire on pin-1 of the IH1 connector behind the glove box to insert the Dakota Digital speed calibrator. (the problem will come in determining which side of the wire goes to the sensor and which goes to the speedo... )