Nissan Sentra Service Manual: U0101 can comm circuit
Description
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
DTC Logic
DTC DETECTION LOGIC
| DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
| U0101 | LOST COMM (TCM) (Lost communication with TCM) | When ECM is not transmitting or receiving CAN communication signal of OBD (emission-related diagnosis) with TCM for 2 seconds or more. | CAN communication line between TCM and ECM |
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
- Turn ignition switch ON and wait at least 3 seconds.
- Check DTC.
Is DTC detected? YES >> Proceed to EC-168, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
Perform the trouble diagnosis for CAN communication system. Refer to LAN-16, "Trouble Diagnosis Flow Chart".
Power supply and ground circuit
Diagnosis Procedure
1.CHECK FUSE
Check that the following fuse is not fusing.
Is the fuse fusing?
YES >> Replace the fuse after repairing the applicable circuit.
NO >> GO TO 2.
...
U1001 can comm circuit
Description
CAN (Controller Area Network) is a serial communication line for real time
application. It is an on-vehicle multiplex
communication line with high data communication speed and excellen ...
Other materials:
ECU diagnosis information
Diagnosis sensor unit
DTC Index
DIAGNOSTIC CODE CHART
NOTE:
Follow the procedures in numerical order when repairing malfunctioning
parts. Confirm whether malfunction is
eliminated using air bag warning lamp or CONSULT each time repair is finished.
If malfunction is still
observed, proceed ...
Tcm branch line circuit
Diagnosis Procedure
1.Check connector
Turn the ignition switch off.
Disconnect the battery cable from the negative terminal.
Check the following terminals and connectors for damage, bend and loose
connection (unit side and connector
side).
TCM
Harness connector f50
Harness co ...
Front suspension assembly
Inspection
COMPONENT PART
Check the mounting conditions (looseness, backlash) of each component. Verify
the component conditions
(wear, damage) are normal.
Ball Joint Axial End Play
Set the front wheels in a straight-ahead position.
Hold the axle side of the transverse link, and check th ...