P1603 Cadillac ECU-TCU Communication Error
Possible causes
– Faulty Transaxle Control Module(TCM) or Engine Control Module(ECM)
– Transaxle Control Module(TCM) to Engine Control Module(ECM) harness is open or shorted
– Transaxle Control Module(TCM) to Engine Control Module(ECM) circuit poor electrical connection
– Transaxle Control Module(TCM) to Engine Control Module(ECM) harness is open or shorted
– Transaxle Control Module(TCM) to Engine Control Module(ECM) circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1603 Cadillac Description
A communication line exists between the Engine Control Module(ECM) and the Transaxle Control Module(TCM). The communication is through a Control Area Network(CAN). Without CAN communication, an independent pin and wiring is needed to receive a sensor information from a ECM. The more information to be communicated, the more wirings is required. In case of CAN communication type, all the information need to be communicated among control modules such as ECM and TCM use CAN lines.
Cadillac Vehicle:Cadillac CTS Coupe, Cadillac CTS-V Coupe , Cadillac Eldorado , Cadillac Escalade EXT , Cadillac ATS , Cadillac CTS , Cadillac CTS Sedan , Cadillac CTS Sport Sedan , Cadillac CTS-V , Cadillac CTS-V Sedan , Cadillac Catera , Cadillac DTS , Cadillac DeVille , Cadillac STS-V , Cadillac STS , Cadillac Seville , Cadillac XTS , Cadillac XLR , Cadillac XLR Platinum , Cadillac Escalade , Cadillac SRX