Maintenance TechThis forum is for discussion of all aspects of maintenance that should be performed on the FJ Cruiser to keep it operating at maximum efficiency.
Does anyone know about recalibrating the speedo on a FJC. Maybe a TruSpeed would work, but no idea on what wire to connect it to. Anybody tried this yet, or have any good ideas of adjusting the speedo for a larger tire?
Location: Somewhere where I don't know where I am. Actually, the OC
Posts: 3,377
Re: FJ Speedometer Recalibration
but i want my mileage to be correct on the odometer. the diff between the stock tires and 33s is about 2.3%. not too much, only about 2 mph difference at 65. so at 65 you are doing 67 i thinks
__________________ 2007 Sun Fusion Cruiser 5AT 4X4
It's mainly stock with some bolt ons
I really, really like stickers
The So-Cal Safari Snorkel Install Guy7chicken necks installed to date
"The mountains are calling and I must go" - John Muir
I have 285/75/16's and on the way back from Harlan KY i checked the odometer with a fj running stock size BFG MT tires. After a 325 mile trip i was only off by 3.2 miles , for every hundred miles driven my odemeter was reading 1 mile less than his. The funny thing was my speedometer was reading about 1 mph faster than his, if he was doing 60 i was at 61 mph. I also got a little better gas mileage, when we filled up after 325 miles he put 15.5 gallons i put 15.3 gallons and his gas light came on before mine . Not a big difference at all.
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07 FJ, At ,Upgrade #2,Toytec 1/2 FR Spacer,Auto Vent Shades,285/75/R16 Dick Cepek FC-11's on 16x8 Ultra 50/51's
i have a navagation system, a tom-tom... it displays the speed, too. when i get my new tires, i'll make a note, untill i can remember on my own when the NAV says i'm going 15, 25, 35, 45, 55, 65, 70... if i am off 2-3mph, i'll just drop it by that on the speedometer.
Location: currently Huntsville, AL, originally from Honolulu
Posts: 1,640
Re: FJ Speedometer Recalibration
Quote:
Terahex previously said:
I got the ScanGageII. You can program it to display your MPH with the larger tires.
Me too. It works and is really cost effective (relative term, I know).
Quote:
MudLovingFJ previously said:
but i want my mileage to be correct on the odometer. the diff between the stock tires and 33s is about 2.3%. not too much, only about 2 mph difference at 65. so at 65 you are doing 67 i thinks
ScanGauge won't help you there. Probably need some electronic work. Personally, I am not too worried about the discrepancy because, 1) it's a Toyota, 2) plan on keeping FJ and handing keys over to son someday.
Are you AT or MT? If MT then the speedo gets input from the speed sensor in the tail of your transfer case. You should be able to tap into the wires leading from the speed sensor to the speedo. If you are AT, the speedo gets input from the Skid Control ECU which gets input from the wheel speed sensors and converts it into a signal the speedo can use. You need to find a copy of the wiring diagram from the FSM. From there you need to find the wires that run from the Skid Control ECU to speedo and install your speed calibration unit.
You should also do a search as someone posted that they had installed a yellow box install unit some time back. Good luck!
It totally depends on what size tire you are going too. I put 285/75/16 Revo's on my FJ and checked the speed with my gps (very accurate) - low and behold - it was right on - concluding it was off with the stock tires - after you change tires - get someone with a gps to go with you - you may not need to do anything.
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