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:
Supplemental air bag warning light
The supplemental air bag warning light,
displaying in the instrument panel,
monitors
the circuits for the air bag systems, pretensioners
and all related wiring.
When the ignition switch is placed in the ON or
START position, the supplemental air bag warning
light illuminates for about ...
Basic inspection
Work Procedure
1.INSPECTION START
Check service records for any recent repairs that may indicate a related
malfunction, or a current need for
scheduled maintenance.
Open engine hood and check the following:
Harness connectors for improper connections
Wiring harness for improper c ...
Intermittent Incident
DESCRIPTION
Sometimes the symptom is not present when the vehicle is brought in for
service. If possible, re-create the
conditions present at the time of the incident. Doing so may help avoid a No
Trouble Found Diagnosis. The fol-
lowing section illustrates ways to simulate the conditions/env ...
