P1603 Audi 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 Audi 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.
Audi Vehicle:Audi A1,Audi A3,Audi A1,Audi A3,Audi A1,Audi A3,Audi A4,Audi A5,Audi Q3,Audi A5,Audi Q5,Audi A3,Audi A4,Audi A5,Audi TT,Audi Q3,Audi Q5,Audi S3,Audi TTS,Audi RS 3,Audi TT RS,Audi A7,Audi Q7,Audi A8,Audi A6,Audi S4,Audi S5,Audi Q5,Audi S6,Audi S8,Audi S5,Audi A8,Audi R8 V8,Audi RS 5,Audi S6,Audi R8 V10,Audi R8 GT,Audi A8L