Nissan Sentra Service Manual: U1000 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 malfunction 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 independently). 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 | CONSULT screen terms (Trouble diagnosis content) | DTC detection condition | Possible causes |
| U1000 | CAN COMM CIRCUIT (CAN Communication Line) | When the ignition switch is ON, TCM cannot send the CAN communication signal continuously for 2 seconds or more. | Harness or connector (CAN communication line is open or shorted) |
DTC CONFIRMATION PROCEDURE
1.PREPARATION BEFORE WORK
If another “DTC CONFIRMATION PROCEDURE” occurs just before, turn ignition switch OFF and wait for at least 10 seconds, then perform the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT
- Start the engine and wait for at least 5 seconds.
- Check the DTC.
Is “U1000” detected? YES >> Go to TM-158, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
For the diagnosis procedure, refer to LAN-16, "Trouble Diagnosis Flow Chart".
U0155 Lost communication (IPC)
DTC Logic
DTC DETECTION LOGIC
DTC
CONSULT screen terms
[Trouble diagnosis content]
DTC detection condition
Possible causes
U0155
LOST COMM (IPC)
[Lost Communication ...
U1117 Lost communication (ABS)
DTC Logic
DTC DETECTION LOGIC
DTC
CONSULT screen terms
[Trouble diagnosis content]
DTC detection condition
Possible causes
U1117
LOST COMM (ABS)
[Lost Communication ...
Other materials:
Removal and installation
Combination meter
Exploded view
Combination meter
Front cover
Removal and installation
Removal
Remove cluster lid a. Refer to ip-19, "removal and installation".
Remove the screws from the combination meter.
Remove the combination meter.
Disconnect the comb ...
Symptom diagnosis
The eco mode indicator lamp does not turn on
Description
The ECO mode indicator lamp does not turn ON when the ECO mode switch is
operated.
Diagnosis Procedure
1.Perform combination meter on board diagnosis
Perform combination meter on board diagnosis. Refer to MWI-16, "Description" ...
Dtc/circuit diagnosis
U1000 can comm circuit
DTC Logic
Dtc detection logic
Consult display
Dtc detection condition
Possible cause
Can comm circuit
[u1000]
Av control unit is not transmitting or receiving
can communication signal for 2 seconds or
more.
CAN communication system.
...