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Home >> Cadillac >> 2016 >> CTS Base, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Data Communication System >> Diagnostic Information and Procedures >> DTC U1804: Lost Communication with Inside Rearview Mirror Control Module >> Diagnostic Fault Information
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Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
B+ U1804 U1804 - -
Low Speed GMLAN Serial Data U0073, U0078* U1804 U0073, U0078* -
Ground - U1804 - -
*Scan tool does not communicate with most low speed GMLAN device
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