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.
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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:
Precaution
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT
BELT PRE-TENSIONER"
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”,
used along
with a front seat belt, helps to reduce the risk or severity of injur ...
General Precautions
Always use a 12 volt battery as power source.
Do not attempt to disconnect battery cables while engine is
running.
Before connecting or disconnecting the ECM harness connector,
turn ignition switch OFF and disconnect negative battery
cable. Failure to do so may damage the ECM because
...
Fuel level sensor signal circuit
Description
The fuel level sensor unit and fuel pump detects the approximate fuel level
in the fuel tank and transmits the
fuel level signal to the combination meter.
Component function check
1.Combination meter input signal
Select meter/m&a on consult.
Using FUEL METER of DATA MONI ...
