"VSL Protection"

TM 9-2320-312-24-2

Troubleshooting Section

"VSL Protection"

"Low Speed Range Axle Ratio"

The "VSL Protection" is the maximum engine rpm

MAR98 and newer Personality Modules.

when there is a problem with the vehicle speed

signal that is detected by the ECM. The ECM limits

The "Low Speed Range Axle Ratio" parameter

the engine to this engine rpm when the ECM senses

must be programmed when an on/off switch for

no vehicle speed signal, and a load on the engine.

the two-speed axle is used by the ECM to adjust

the vehicle speed calibration. When a two-speed

This is a feature that is used to prevent tampering by

running without a Vehicle Speed input to the ECM.

axle is used, the change in gear ratios from the

high speed range to the low speed range alters the

Note: When this parameter is programmed to the

calibration of the vehicle speed signal. Since the

vehicle speed signal has been altered, a calibration

TEL rpm, the ECM disables 84-01 Loss Of Vehicle

Speed Signal (31) and 84-10 Vehicle Speed Rate

adjustment is required to ensure that the ECM

of Change (36) and the "VSL Protection" may be

driven speedometer and the information that is

exceeded by disconnecting the vehicle speed

stored in the ECM correctly reflect the actual vehicle

sensor.

speed. This parameter should be programmed to

the "Low Speed Range Axle Ratio". This parameter

Table 137

only requires programming when the "Two-Speed

Axle Switch" parameter is enabled.

Manufacturer

Minimum

Maximum

Default

"1700 rpm"

"1700

Table 140

rpm"

Minimum

Maximum

Default

1700 rpm

Other

TEL rpm

TEL rpm

0.00

19.99

0.00

"Tachometer Calibration"

"High Speed Range Axle Ratio"

The "Tachometer Calibration" is used by the ECM

This parameter only requires programming when

to translate the engine speed signal into revolutions

the "Two-Speed Axle Switch" parameter is enabled.

per minute for a tachometer. The "Tachometer

The "High Speed Range Axle Ratio" must be

Calibration" is programmed in pulses per revolution

programmed when an on/off switch for the

(PPR). The programmable range is from 2.0 to 500.0

two-speed axle is used by the ECM to adjust the

in increments of 0.1 PPR.

vehicle speed calibration. When a two-speed axle

is used, the change in gear ratios from the high

Table 138

speed range to the low speed range alters the

Manufacturer

Minimum

Maximum

Default

calibration of the vehicle speed signal. Since the

vehicle speed signal has been altered, a calibration

17.5

2.0 PPR

500.0 PPR

adjustment is required to ensure that the ECM

PPR

driven speedometer and the information that is

134.0

Other

2.0 PPR

500.0 PPR

stored in the ECM correctly reflect the actual vehicle

PPR

speed. This parameter should be programmed to

the "High Speed Range Axle Ratio".

"Soft Vehicle Speed Limit"

Table 141

Minimum

Maximum

Default

The "Soft Vehicle Speed Limit" operates in

conjunction with the "Vehicle Speed Limit". The

0.00

9.99

"0.00"

"Soft Vehicle Speed Limit" limits the vehicle speed

within the following range:

The minimum value is 4 km/h (2.5 mph) below the

programmed "Vehicle Speed Limit" at full load.

The maximum value is 4 km/h (2.5 mph) above

the selected "Vehicle Speed Limit" at no load.

Table 139

Manufacturer

Alternative

Default

All Applications

"NO"

"YES"