Suzuki Baleno Manual page 1442

6-2-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS (J18 ENGINE WITH WU TWC)
DTC P1600 SERIAL COMMUNICATION PROBLEM BETWEEN ECM AND TCM
WIRING DIAGRAM
CIRCUIT DESCRIPTION
The serial data line is pulled up to about 5 V by ECM and TCM transmits information to ECM through it by controlling
its grounding.
TCM constantly sends information while ignition switch is ON as to whether judgement was made or not with re-
spect to all detectable DTCs as well as whether or not abnormality exists after judgement.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION
No signal inputted from TCM to ECM or check sum error while
engine running.
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it at idle for 5 min. or more.
4) Check DTC and pending DTC.
TROUBLE AREA
"G / W" circuit open or short
D D
TCM power or ground circuit open
D
TCM malfunction
D
ECM malfunction
D