Control System75Service Manual – CS7000TroubleshootingControl Panel LEDs all stay lit - CAN Bus problemsIf communication on the CAN bus fails, the operator may or may not notice anything. If they notice anythingit will likely be that the control panel powers up when the key is turned on but all of the LEDs remain litand there is no response to pushing any switch on the control panel.Control panel appearance with CAN Bus failureIf this happens, start by checking to see if either the steering controller or drive controller is causing theproblem by unplugging their low current connectors one at a time. If normal operation is restored afterunplugging one of the controllers, that controller is corrupting the communication on the CAN Bus andshould be replaced.Next inspect the CAN Bus wires for shorts to ground, shorts to power or short to one another.• Turn the key off and unplug the control panel, the main machine controller, steering controller and thedrive controller connectors.• At the main machine controller connector, check for the presence of voltage on each of the CAN Bus wires.If there is voltage (example 12v or 36v), the wire is shorted to a voltage source. Find and correct the shortcircuit.• Using an ohmmeter, check for continuity between each of the CAN Bus wires and battery negative. Ifcontinuity is found, there is a short to ground (battery negative). Find and correct the short circuit.• Using an ohmmeter, check the continuity of all of the wires from the main machine controller connectorto each of the other connectors. If any wire does not have continuity there is an open. Find and correct theopen circuit.If the wiring is not the problem, check to see if the main machine controller is capable of providing the“bias” voltage on the circuit.• Make sure the key is off and then plug in only the main machine controller.• Turn the key on and then check the voltage on each of the CAN Bus wires at the Control Panel Connector.If there is no voltage, the main machine controller is defective because it is not providing bias voltage.If the voltage on the CAN Hi (YEL) wire is approximately 3.3v and the voltage on the CAN Low (GRN) wireis approximately 1.8v, the main machine controller is providing the bias voltage. This indicates that thecontrol panel is the source of the problem and needs to be replaced.
