New Freightliner Cascadia, no electrical power from battery cable access module in cold temperatures

Applicable Vehicles

All New Cascadia equipped with a Cab Load Disconnect Switch (CLDS).

Symptoms

In very cold weather, if a truck has been parked outside with the CLDS turned off, the Battery Cable Access (BCA) module might not provide power to the vehicle when the CLDS is turned on.

The situation is more pronounced in extreme cold temperatures experienced in the northern United States and Canadian provinces.

This issue has been reported during winter months, and from geographic regions that have experienced  extremely cold temperatures.

Issue

As the outside temperature drops, the contactor inside the BCA requires more current to switch from its "off" to its "on" state. The switching current for the contactor is provided by an electronic circuit board inside the BCA.

As outside air temperatures drop, the BCA internal temperature also drops, and may reach a temperature that is too low for the components on the circuit board to provide the necessary current for the contactor to switch.

There is not an exact temperature at which the problem will occur. Some vehicles have experienced the problem at -5 degrees Celsius / 22 degrees Farenheit; others have experienced temperatures as low as -40 degrees Celsius (-40 degrees Farenheit) before experiencing the issue.

The problem has been duplicated in cold chamber testing.

Solution

Apply warm - not hot - air to the exterior of the BCA for up to one minute to raise the internal temperature of the electronics. Removing the fuse cover can speed this process up.

Replacement of the BCA will only appear to solve the issue. As noted above, there is not an exact temperature at which the issue will occur, and replacing the BCA may merely send the problem down the road.

A redesign of the circuit board is being investigated. Ongoing shortages of electronic components are making it difficult to source new parts.