Serial Data Circuit - Multiple Intermittent Codes

Wiring Diagram:

CIRCUIT DESCRIPTION

A damaged data line circuit or one of the components connected to the data line may cause multiple or intermittent setting of data line Codes B333, B334, B335, B336 and/or B337. When operating normally, the serial data line voltage should continually fluctuate from 0.1 to 5 volts.

If the serial data line has been shorted to ground, the voltage at the ALDL will be 0 volts. If it has been shorted to voltage, it will be over 5 volts. If one of the components on the serial data line is affecting the data line voltage, the serial data voltage at Data Link Connector will be a steady value anywhere between 0.1 and 5 volts.