AC DRIVE SPEED CONTROLLER ERROR CODES

The Curtis 1238 AC controller provides diagnostic information to assist in the troubleshooting of drive system problems in a similar fashion as the DC controller.  The diagnostic information can be obtained by observing the appropriate display on the handheld programmer or the fault codes issued by the 2 Status LEDs.  The pair of LEDs built into the controller (one red, one yellow) produce flash codes displaying all the currently set faults in a repeating cycle.  Each code consists of two digits.  The red LED flashes once to indicate that the first digit of the code will follow; the yellow LED then flashes the appropriate number of times for the first digit.  The red LED flashes twice to indicate that the second digit of the code will follow; the yellow LED flashes the appropriate number of the times for the second digit.  An example of the code for “Battery Under-Voltage” (code 23) is shown in the following flash sequence diagram.

The LEDs have 4 different displays modes that indicate the type of information they are providing.  These types are summarized in Table 6 below.

The following troubleshooting chart (Table 7) provides the following information on all the controller faults including the ways to identify each fault, possible causes, and the “set” and “clear” conditions associated with each.  Whenever a fault is encountered and no wiring or vehicle fault can be found, shut off the key switch and turn it back on to see if the fault clears.  If not, shut off the key switch and remove the 35-pin connector to the controller.  Check for connector corrosion or damage, clean it if necessary, and re-insert it.