| • | No DTCs are set. | 
| • | The control modules can communicate via the serial data link. | 
| • | Inspect for aftermarket devices which could affect the operation of the RCDLR system. Refer to Checking Aftermarket Accessories . | 
| • | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom. | 
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: