sssagiledriver
New member
Has anyone had any luck trying to correct the speedometer error? My T1N/Roadtrek Agile reads about 5 mph fast at 65 (actual speed 60).
Are your tires the factory/stock rim and tire size?Has anyone had any luck trying to correct the speedometer error? My T1N/Roadtrek Agile reads about 5 mph fast at 65 (actual speed 60).
it should be 5 mph less not advanced.
MB has a specific built-in error of margins 10% - and 10% + [A]..because of electronics, and ..as to varying tire sizes and or dimentaions.
Hence as an example your trip meter is 99.999999% accurate.
Richard
True but who runs smaller than 15"?If they are smaller diameter it will read higher.
Ya neva know what some folks do.True but who runs smaller than 15"?
Sprinters are designed to run 15' and 16" plus the size variations or differencing tread patterns of heights and width. .
Richard
I know that's why I'm asking tooYa neva know what some folks do.
I up sized my tires. Now over 1.25" larger in diameter. (Point the stock sized Contis were 0.5" smaller than the Michelin equivalent). My speedy now says I'm going 5-7mph slower than I am. The MPG meter now tells me I get 15% less MPG's.
My dishes rattling in the sink tell me what speed I'm driving, the change left in my pocket tell me how many miles to gallon I got.
But nobody has answer this persons original question. this is typically what happens when Richard gets in there. Richard everybody knows different tyres sizes at a set speed, turn at different RPM"s. This person wanted to know if there is a calibration for the speed-o-meter, screw the tyres.Has anyone had any luck trying to correct the speedometer error? My T1N/Roadtrek Agile reads about 5 mph fast at 65 (actual speed 60).
Yes Richard quite right.MB deliberately builds in an error margin to cover themselves as other manufactures do.
OUCH!Yes Richard quite right.
The answer to the question ! yes it can be done.
2 no it can not be done
So the CAB sends the message, and the Instrument Cluster processors move the needle.The speedometer consists of a movable gauge needle or pointer controlled by the instrument cluster circuitry and a fixed 210 degree primary outer scale on the gauge dial face that reads left-to-right either from “0” to “100” miles-per-hour, or from “0” to “180” kilometers-per-hour, depending upon the market for which the vehicle is manufactured.
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This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Controller Anti-lock Brake (CAB) over the Controller Area Network (CAN) data bus. The speedometer is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board when the instrument cluster detects that the ignition switch is
in the On position. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the Off position. The instrument cluster circuitry controls the gauge needle position and provides the following features:
* Vehicle Speed Message - Each time the cluster receives a vehicle speed message from the CAB it will calculate the correct vehicle speed reading and position the gauge needle at that relative speed position on the gauge scale. The gauge needle will continue to be positioned at the actual vehicle speed position on the gauge scale until the ignition switch is turned to the Off position
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The CAB continually monitors the four wheel speed sensors to determine the vehicle road speed.
The CAB then sends the proper vehicle speed messages to the instrument cluster.
For proper diagnosis of the wheel speed sensors, the CAB, the CAN data bus, or the electronic message inputs to the instrument cluster that control the speedometer, a DRBIIIt scan tool is required. Refer to the appropriate diagnostic information