3100 HEUI Vehicle Speed Parameters

Vehicle Speed Calibration
The ECM uses this value to scale the vehicle speed signal into miles per hour. It is programmed in pulses per mile (PPM). This parameter must be programmed or a Diagnostic Code 253-02 Check Customer Or System Parameters (56) will occur. This parameter affects cruise control, progressive shifting, the ECM speedometer signal, and can affect PTO operation. For more information, refer to “PB-14: Vehicle Speed Circuit Test” on page 91.

Vehicle Speed Limit (VSL)
Top vehicle speed the ECM will permit. The ECM will shut off fuel above this speed. An inexperienced driver may think something is wrong with the engine, because the engine will not fuel above this vehicle speed limit.

VSL Protection

Maximum engine rpm when there is an ECM detected vehicle speed signal problem. The ECM limits to this engine rpm when it senses no vehicle speed signal, and the engine is loaded. This is a feature to deter tampering by running without a Vehicle Speed input to the ECM.


NOTE: When this parameter is programmed to 3000 rpm, Diagnostic Codes 84-01 Loss Of Vehicle Speed Signal (31) and 84-10 Vehicle Speed Rate of Change (36) are disabled, and the VSL Protection can be exceeded by disconnecting the Vehicle Speed Sensor.

Tachometer Calibration

The ECM uses this value to scale the engine speed signal into revolutions per minute for a tachometer. It is programmed in pulses per revolution (ppr). Programmable range is from 12.0 to 500.0 in 0.1 ppr increments.

Soft Vehicle Speed Limit

This limit operates in conjunction with the Vehicle Speed Limit. It limits the vehicle speed from 2.5 mph (4 km/h) below the programmed Vehicle Speed Limit at full load, to 2.5 mph (4 km/h) above the selected Vehicle Speed Limit at no load. Some applications with a JUN97 or later Personality Module may only offer a NO option.

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