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U0100 on the 2009 Cadillac SRX

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

Bulletins for this model year that name U0100
PIC4740E2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles with the Service Engine Soon light is on, Reduced engine power message, no crank, multiple warning lights on, transmission shifts hard, or the door locks cycle while driving. The Transmission Control Module or Engine Control Module may not communicate. With Diagnostic Trouble Codes C0242, C0561, P0575, P0615, P0700, P0856, P1629, P2544, U0073, U0074, U0100, U0109, U0121, U0140, U2100, U2105, and / or U2106 stored. The technician is to inspect the transmission X1 connector terminals for loose or poor fit. Disconnect the X1 connector and carefully tug on each wire to insure pins are fully seated. A side load on the wires may also cause a false positive lock. Technician is to repair the connections as necessary.
PIC5460B2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician on how to diagnose and repair vehicles with a no crank concern or they are unable to remove their key from the ignition lock cylinder may find Diagnostic Trouble Codes P0318, P1629, U1040, U1064, U1153, U1192, and U1300 stored in the Engine Control Module. Other Class 2 modules may have a U0100 and/or U1000 code stored. These concerns may be caused by an Ignition 1 Power Feed (circuit 5290) or Class 2 (circuit 1807) wiring concern to the Engine Control Module. If the electrical center ignition relay feedback parameter in the Engine Control Module is not battery voltage, measure the voltage at the Engine Control Module fuse in the under-hood fuse block. If voltage is less than battery voltage, check to make sure the Power Control Module is turning the relay on via circuit 5069. If there is battery voltage at the Engine Control Module fuse, check Ignition 1 (circuit 5290) between the fuse and the Engine Control Module. If Ignition 1 (circuit 5290) to the Engine Control Module checks ok, check for a possible open in the Class 2 (circuit 1807) to the Engine Control Module. If all connections and wiring are OK, suspect a possible relay or an ECM concern.
PIC4740D2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles with the Service Engine Soon light is on, Reduced engine power message, no crank, multiple warning lights on, transmission shifts hard, or the door locks cycle while driving. The Transmission Control Module or Engine Control Module may not communicate. With Diagnostic Trouble Codes C0242, C0561, P0575, P0615, P0700, P0856, P1629, P2544, U0073, U0074, U0100, U0109, U0121, U0140, U2100, U2105, and / or U2106 stored. The technician is to inspect the transmission X1 connector terminals for loose or poor fit. Disconnect the X1 connector and carefully tug on each wire to insure pins are fully seated. A side load on the wires may also cause a false positive lock. Technician is to repair the connections as necessary.
PIC4740C2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles with the Service Engine Soon light is on, Reduced engine power message, no crank, multiple warning lights on, transmission shifts hard, or the door locks cycle while driving. The Transmission Control Module or Engine Control Module may not communicate. With Diagnostic Trouble Codes C0242, C0561, P0575, P0615, P0700, P0856, P1629, P2544, U0073, U0074, U0100, U0109, U0121, U0140, U2100, U2105, and / or U2106 stored. The technician is to inspect the transmission X1 connector terminals for loose or poor fit. Disconnect the X1 connector and carefully tug on each wire to insure pins are fully seated. A side load on the wires may also cause a false positive lock. Technician is to repair the connections as necessary.

4 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.