Diagnostic Trouble Code (DTC) Output Format Description

Fig. 14 Code output format:

The engine control system communicates service information by way of the self test service code. These service codes are two-digit numbers representing the results of the self test. The service codes are transmitted on the self-test output (STO, found in the self-test electrical connector) in the form of timed pulses, Fig. 14, and may be ``read'' through the use of an analog voltmeter, Super Star II Tester or equivalent.