Dtc P1778: Tcm Lost Communication With Bcm (Reception Error) - Suzuki Grand Vitara 2011 Manual

5A-73 Automatic Transmission/Transaxle:

DTC P1778: TCM Lost Communication with BCM (Reception Error)

Wiring Diagram
Refer to "DTC P1774: CAN Communication Bus Off".
DTC Detecting Condition and Trouble Area
DTC Detecting Condition
Reception error of communication data for BCM is detected for
longer than specified time continuously.
(1 driving cycle detection logic)
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
Upon completion of inspection and repair work, perform "DTC Confirmation Procedure: ""DTC
Confirmation Procedure" and confirm that the trouble has been corrected.
Step
1 Was "A/T System Check" performed?
2 Control module connector check
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Recheck DTC in TCM referring to "DTC Check".
Is there DTC P1778?
3 DTC check in BCM (bus off)
1) Check DTC in BCM referring to "DTC Check in Section
10B".
Is there DTC U1073?
4 DTC check
1) Check DTC in ECM referring to "DTC Check: For Petrol
Engine Model in Section 1A".
Is there DTC P1678?
5 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules
communicating by means of CAN.
3) Check CAN communication circuit between control
modules for open, short and high resistance.
Is each CAN communication circuit in good condition?
Action
Trouble Area
• BCM
• TCM
• CAN communication line circuit
Yes
Go to Step 2.
Go to Step 3.
Go to "DTC U1073 (No.
1073): Control Module
Communication Bus Off
in Section 10B".
Check BCM power and
ground circuit. If circuit
is OK, substitute a
known-good BCM and
recheck.
Check TCM power and
ground circuit. If circuit
is OK, substitute a
known-good TCM and
recheck.
S6JB0A5104043
No
Go to "A/T System
Check".
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection in Section
00".
Go to Step 4.
Go to Step 5.
Repair circuit.