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Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Data Communication System - DTC B1000 To DTC U1818 >> Diagnostic Information and Procedures >> DTC U1818: Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus >> Diagnostic Fault Information
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Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
B+ U1818 U1818 - -
Ignition U1818 U1818 - -
Accessory Wake Up Serial Data 2 P06E4* U1818 - -
Powertrain High Speed GMLAN Serial Data (+) U0074* U1818, U0074* U0074* -
Powertrain High Speed GMLAN Serial Data (-) U0074* U1818, U0074* U0074* -
Ground - U1818 - -
* Other DTCs may set with this fault.