ECD SYSTEM(w/ Glow Plug Controller), Diagnostic DTC:U1103

DTC Code	DTC Name
U1103	Lost Communication with Stop and Start Control Module

DESCRIPTION

The ECM and engine stop and start ECU communicate with each other via CAN communication. The engine stop and start ECU also communicates with other computers through the ECM. If there is a problem with this communication, the ECM illuminates the MIL and stores this DTC.


DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
U1103	Lost Communication with Stop and Start Control Module	No communication between ECM and engine stop and start ECU (1 trip detection logic).	Wire harness (CANL and CANH circuits) ECM Engine stop and start ECU	-	DTC stored

Table 1. DTC Detection Drive Pattern
DTC No.	DTC Detection Drive Pattern
U1103	Ignition switch ON

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Tip:

When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system first.
Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
If the CAN communication system is malfunctioning, there is no data output from the ECM. In this case, some of the freeze frame data will not be correct and not identical with the ECM data, but the ECM data are correct.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U1103)

Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: System Select / Health Check.

Read the DTCs.

Result


Result	Proceed to
DTC U1103 is output	A
DTC U1103 and other DTCs are output	B

Tip:

If any DTCs other than U1103 are output, troubleshoot those DTCs first.

A

GO TO CAN COMMUNICATION SYSTEM FOR TROUBLESHOOTING

w/ Central Gateway ECU:Click here
w/o Central Gateway ECU:Click here

B

GO TO DTC CHART