Mack Truck Electronic V-MAC IV Vehicle Management & Control with Co-Pilot Display Operator’s Manual

52 V-MAC Co-Pilot Operator’s Manual This section explains the procedure to reset the low idle speed using the Speed Control switches.

The vehicle management and control (V-MAC) IV system allows the low idle to be set within the range of 550 to 700 RPM (650–700 RPM for non-catalyzed exhaust aftertreatment system). This provides flexibility to set the low idle to the smoothest engine speed for the vehicle.

There are two steps required to reset the low idle speed. The first step places the vehicle management and control (V-MAC) IV system into the low-idle adjust mode.

In this mode, vehicle management and control (V-MAC) IV is ready to accept the new idle speed.

The second step is to actually tell vehicle management and control (V-MAC) IV what the new idle speed will be.

The first phase in the process is meeting the requirements listed below.

1 The vehicle management and control (V-MAC) IV system must have the Low-Idle Adjust option enabled in the customer data space. This function can be disabled by the customer.

2 Be sure there are no active faults in the system.

3 The vehicle must be stationary.

4 The parking brake must be applied.

5 The accelerator pedal (AP) must be at the idle position (not pressed).

6 The Speed Control ON/OFF switch must be turned ON and OFF 3 times within two seconds. At this point, the idle speed will drop to 550 RPM, and vehicle