Rough country inline speedometer calibrator

I just bought a used Hypertech from this For Sale section and there was a wire pulled from the connector. Not an easy fix because of the small size of the pins and all wires are black. Hypertech agreed to fix it for me at a price but pisses me off I did not pull a wire out by taking it out of the box. Tried to get a little compensation from the seller but no reply, he is not happy but I do not think he is as pissed off as I am.

I did not see the Rough Country option, I could have bought that and installed it for the price I paid for a broken one

 

Talked to rough country, they said it works for the 2020 so I ordered one. Installed last night. Only thing this morning was it seemed to have lost the initial programming and I had to do it over. Besides that its working. Anyone else have an issue with having to re-program?

 

I installed mine but it had a problem when I put in 275/55R20 for the original tire size and 35" for new size. The calculation looked backward to me but assumed that is the way the program works. When I drove it I confirmed I was right and had to reprogram. I then found the real size of that tire and put in both tire sizes by actual dimension and it worked... almost. The numbers are off still so I need to dial it in. Not easy task because I do not see anything that tells how to manually program it.

 

2020 Toyota Tundra SR5 4x4 with Toyota Safety Sense

I just installed Rough Country/Hypertech speedometer calibrator this morning after updating the firmware and inputting my parameters. Factory size 275.65.18 and new 295.70.18 (34.2"). Speedometer now reads 1-2 miles over gps and radar, which is okay by me. But if I entered the actual diameter of the tire when I measured it, it would have been dead on.

But, there's always a but. On my way home, I set the cruise control to 75, and speedo and gps reads 79mph. Whoa!!! slow down, set the cruise to 72 and that locked it to 75.

I called Rough Country tech support and they said that it does not show in their system or Hypertech's website if it's compatible. They are offering my a complete refund it I return it.
I called Hypertech to see if they are going to do an update, and they said they have to look at the sales if there is a demand for it before they can do anything else, but eventually, they will get into it. When I mentioned about the dynamic cruise control, they said, they still have not figured that out.

Hypertech/RC works, but set your cruise control and adjust base on the speedometer, not the cruise control speed.

 

This is interesting... I just added a Rough Country speedo calibrator because I bought a used Hypertech on here from sstoddard and it had one wire come loose from the connector pin and when looked at closer they all were loose. Needless to say that one was trash and I lost my ass since electronics is hard to govern when a situation occurs. Whatever

When I got the Rough Country in and updated the firmware and then calibrated it the ratio number did not look correct (looked opposite to me) to me but figured they know what they are doing and I left it as it was. When I drove it I found that it was indeed reversed and the gap in the speedo reading and actual speed was way off. I went in and changed the settings this time to the actual tire size in inches (the first time I put the factory tire size 275/55R20 and new tire size 35) and it worked fine. I seen at low speeds I was not quite 2 miles over but at 75 I was doing 79 which is normal since the ratio the gap between the speedo and actual increase with speed.

I have changed the size several times trying to get the ration number into the value I calculated it should be but each time the low speed difference was about the same. I have to admit each and every time I was checking my speed it was with the cruise control set and I have the adaptive radar on my 2018. Now I need to do more testing with no radar and see how the numbers stack up. This is interesting.

I called and talked to Rough Country and asked if I could just change the ratio value to what I calculated and he said no our software does not allow you to do that. I told him that the software that they use was Hypertech's and he said he did not know that. In the end he told me to just keep playing with the numbers until the value for the ratio is what I need. Now this brings up another issue with the cruise control which 80% of my driving is all cruise control

 

Hypertech makes Rough Country calibrator. That's where the customer support re-verify if the RC calibrator is going to be compatible with 19-20. Since you have the ACC (Adaptive Cruise Control) on your 18, you fall under the 19-20 category too. Not 100% compatible. You just have to adjust your speed in when ACC is engage.

I left the USB plugged in and had it tucked under the dash as well for future reprogramming. So I do not have to take the cluster apart again and misplace another screw.

 

I did the same thing, I have the USB cable behind the drivers kick panel. I had a cop coming after me on the highway on the way to work yesterday and I realized how fast I was going and was getting off an exit. By the time I got off and turned down the first street to my work I never seen the cop. Not sure he was after me but got me thinking about this and how easy it is to forget while driving and not having to do constant math

 

My speedo reads 75, but doing 73-74 via GPS. I'll keep it that way instead of making it precise. But definitely drop 3mph on acc setting.

 

Yesterday on my way home I was watching the GPS just next to the instrument cluster and was not using Cruise Control and I did not see a difference. I then decided to get in a constant speed that is steady then turned on the CC and watched but the dash and GPS speed stayed the same.

Does anyone else in hear have a 2018 Platinum with a “Rough Country” calibrator that has the same speedometer problem with CC?

 

Tony, It will all vary depending on the tire size as well tony. My actual tire diameter is 33.75 dismounted, mounted @55psi is 33.25 on an 18x9 wheel and fully loaded bed. The same tire on an 18x8 will be a little taller with the same psi and load. Then a completely different tire will have a different diameter all together having more rubber. Toyota calibrated the speedometer to to close to the tire size they offer for the vehicle and for safety/liability, makes it read a little higher.

295.70.18
Wild Peak 34.3
Trail grapler 354.5
AT3 XLT 34.25 =33.75 actual

Before swapping tires, still on steel wheels and 255.70.18. My speedo was already off by a 1-2 mph between 70 and 75 mph. I can make my calibration more precise, but I'd rather read higher and going slower. I go over 10 all the time, don't want to get clocked going 10, 8-9 will be safe.

 

just read all threads now I can sleep seeing everyone is as confused as me lol ok so the Rough Country is made by hypertech. which one should purchase for a 2019 TRDPRO i insist on driving my truck until I fix this. really don't want to throw my miles off too much.

thanks in advance

 

You're the only person I've found that installed a calibrator in a 2019-2020. What did you take apart to get to the connector? Any links to tutorial videos? I can't find jack for our years... Same procedure for 2014-2018? Also, have you noticed if it adjusts the odometer too? I really don't care about the cruise control issues.

 

I'll try to write down the procedure when I get home.

 

No worries, I ended up figuring it out yesterday. I didn't realize you had to take the whole cluster out. Basically start taking the parts under steering wheel apart and work your way up. The only thing I fucked up was the piece of fabric between the dash and the steering column cover...

 

Yup, I did not hook that fabric back in place.

 

I tried but after 45 minutes of raging I just shoved it back above it lol

 

So after reading all the speedometer calibration threads I could find on here it looks like the RC is the best option for a 2020. Still not clear though. So the RC works for the speedo but not the digital display and not for cruise control, is that right??

 

Im just wondering do you have to leave the RC device plugged into your OBDII all the time ? If not how do you get it to program to your truck ?

 

It’s doesn’t plug into the obd. It plugs inline to the harness to the instrument panel.

 

I just installed the RC speedometer calibrator on my 2015. Everything works fine, GPS indicates spot on all the way up through 65 mph at least.

however, now the instrument panel display screen for “miles to empty” says “low fuel”. Any ideas? Guess I’ll be calling customer support tomorrow…

edit: I have almost a full tank of gas.

 

edit: issue resolved. just needed to drive it a few miles so distance to empty could be recalculated.

 

Does anybody have a RC Speedometer Calibrator and an aftermarket remote starter? I'm having issues with my aftermarket (Compustar) remote start. The remote/brain thinks the truck is running, but the truck just cranks then the factory alarm goes off.

RC and Hypertech both are saying they've never heard of this issue.

 

In the calibration phase, do you put in the OEM tire/wheel size the dealer installed or the stock tire size from the factory? I'm assuming factory.

 

I would go with factory. I put in factory and updated size (using tire manufacturer specs found on their website), and my speedometer is reading about 3-5MPH higher than what Google Maps says I'm driving which I'm fine with.

 

Hmm. I'm reading my speedo with that sort of gap in accuracy as it stands now

 

DOH! ...I mean mine is reading 3-5 MPH LOWER than Google maps. Before RC calibrator I was about 7-10MPH higher than Google maps.

 

Ahhhh. I still hope to get it closer to actual

 

I'm sure I could tweak it closer, but I was fine with it. I tucked the USB connector under the dash near the hood pull so I can access it easily for updates and to check the programming.

 

Try the OEM size that comes with the factory 18" wheels, think it was 275/65r18. My hypertech is right on the mark with 35s.

 

Thanks guys. Been reading the reviews on their site and looks like you can choose not to adjust gear shift points which is great considering my DAP tune does that already