Dtc P1777: Tcm Lost Communication With Ecm (Reception Error) - Suzuki GRAND VITARA Owner's Manual

5A-66 Automatic Transmission/Transaxle:

DTC P1777: TCM Lost Communication with ECM (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 ECM 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: " 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 P1777?
3 DTC check in ABS hydraulic unit / control module
1) Check DTC in ABS hydraulic unit / control module.
Is there DTC U1100?
4 DTC check
1) Check DTC in ECM referring to "DTC Check: in Section
1A".
Is there DTC P1674?
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
• ECM
• ABS hydraulic unit / control module
• TCM
• CAN communication line circuit
Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Go to "DTC P1674:
CAN Communication
(Bus Off Error): in
Section 1A".
Check TCM power and
ground circuit. If circuit
is OK, substitute a
known-good TCM and
recheck.
S5JB0A5104058
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 5.
Check ECM power and
ground circuit. If circuit
is OK, CAN
communication circuit
between ECM and ABS
hydraulic unit / control
module is open circuit.
Repair circuit.