TRANSMISSION AR 0R4015 - Caterpillar

Diagnostic Indicator
Illustration 1 g00853896
(1) Diagnostic indicatorThe diagnostic indicator is a single LED. The LED is used in order to aid the operator in the identification of diagnostic codes. When the ECM provides a 12 volt signal to the indicator, the LED is ON. When the ECM provides a 0 volt signal to the indicator, the LED is OFF. When the inputs for the harness plug are in the correct configuration, the diagnostic indicator flashes active diagnostic codes and the indicator flashes logged diagnostic codes that are stored in the ECM. See Troubleshooting Testing and Adjusting, RENR5539, "Using the Diagnostic Indicator to Determine Diagnostic Codes".