GUARD AS 7G0339 - Caterpillar

Table 2
Minimum     Maximum     Default    
0 revolutions per km (0 revolutions per mile)     43000 revolutions per km (65000 revolutions per mile)     "Not Programmed"    "Vehicle Speed Cal (J1939 ABS)"
The "Vehicle Speed Cal (J1939-ABS)" is used to calculate vehicle speed with the input from the wheel speed. The data from the wheel speed is transmitted via the J1939 data link. The "Vehicle Speed Input" parameter must be programmed to "Vehicle Speed Cal J1939-ABS". The manufacturer of the ABS system must transmit tire revolutions per mile that is based on the tire size. If the tire size is changed from tire size that is programmed in the ABS system, the "Vehicle Speed Cal (J1939-ABS)" must be changed. The value that is contained in the "Vehicle Speed Cal (J1939-ABS)" parameter is a ratio. If the actual tire size is equal to the tire size that is programmed in the ABS system, the "Vehicle Speed Cal (J1939-ABS)" parameter will be "1". The ratio can be found by dividing the tire revolutions per mile that is transmitted by the ABS system by the actual tire revolutions per mile. Contact the manufacturer of the ABS system in order to verify that this message is supported.If the "Vehicle Speed Input" parameter is programmed to "Vehicle Speed Cal J1939-ABS", this parameter must be programmed. If this parameter is not programmed, the diagnostic code 253-02 that is Check Customer or System Parameters (56) will occur. This parameter affects the cruise control and the ECM speedometer signal. Also, this parameter can affect the PTO operation, extended idle and trip totals.
Table 3
Minimum     Maximum     Default    
0     6.550     "Not Programmed"    "Vehicle Speed Limit (VSL)"
The "Vehicle Speed Limit" (VSL) is the maximum vehicle speed that is allowed by the ECM. The ECM will shut off fuel above this speed. An inexperienced driver may think that something is wrong with the engine because the ECM will not fuel the engine above this vehicle speed limit. Vehicle speed limiting allows the implementation of a gear fast/run slow specification for the truck. The gear fast/run slow specification for the truck improves fuel economy while the parameter for the vehicle speed limit limits the maximum vehicle speed of the truck.
Table 4
Minimum     Maximum     Default    
48 km/h (30 mph)    
204 km/h (127 mph)    
204 km/h (127 mph)    "VSL Protection"
The "VSL Protection" is the maximum engine rpm when there is a problem with the vehicle speed signal that is detected by the ECM. The ECM limits the engine to this engine rpm when the ECM senses no vehicle speed signal, and a load on the engine. This is a feature that is used to prevent tampering by running without a Vehicle Speed input to the ECM.Note: When this parameter is programmed to the TEL rpm, the ECM disables the diagnostic code 84-01 that is Loss Of Vehicle Speed Signal (31) and 84-10 that is Vehicle Speed Rate