Nissan Sentra Service Manual: U1000 CAN Comm circuit
Description
CAN (Controller Area Network) is a serial communication system for real time application. It is an on-vehicle multiplex communication system with high data communication speed and excellent error detection ability.
Many electronic control units are equipped into vehicles, and each control unit shares information and links with other control units during operation. With CAN communication, control units are connected with two communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits and receives data but selectively reads required data only. Refer to LAN-30, "CAN COMMUNICATION SYSTEM : CAN Communication Signal Chart".
DTC Logic
DTC DETECTION LOGIC
| CONSULT name | DTC | DTC detecting condition | Repair order |
| CAN COMMUNICATION FAILURE | U1000 | When air bag diagnosis sensor unit is not transmitting or receiving CAN communication signals for 2 or more seconds. | Refer to SRC-43, "Diagnosis Procedure". |
DTC CONFIRMATION PROCEDURE
1.PERFORM SELF-DIAGNOSIS
- Turn ignition switch ON and wait for 7 seconds or more.
- Using CONSULT, perform SELF-DIAGNOSIS RESULTS of AIR BAG.
- Check if any DTC is displayed in the self-diagnosis results.
Is DTC detected? YES >> Refer to SRC-43, "Diagnosis Procedure".
NO >> Refer to GI-39, "Intermittent Incident".
Diagnosis Procedure
1.CHECK CAN COMMUNICATION SYSTEM
Check CAN communication system. Refer to LAN-16, "Trouble Diagnosis Flow Chart".
>> Inspection End.
U1010 Control unit (CAN)
Description
Air bag diagnosis sensor performs self-tests on key ON. If CAN communication
failure within control unit is
detected, DTC is set.
DTC Logic
DTC DETECTION LOGIC
CONSULT name ...
Other materials:
Ignition switch (if so equipped)
WARNING
Never remove or turn the key to the
LOCK position while driving. The steering
wheel will lock (for models with a
steering lock mechanism). This may
cause the driver to lose control of the
vehicle and could result in serious vehicle
damage or personal injury ...
Basic inspection
Diagnosis and repair workflow
Work Flow
OVERALL SEQUENCE
DETAILED FLOW
1.OBTAIN INFORMATION ABOUT SYMPTOM
Interview the customer to obtain as much information as possible about the
conditions and environment under
which the malfunction occurred.
>> GO TO 2.
2.CHECK SYMPTOM
...
Strg branch line circuit
Diagnosis procedure
1.Check connector
Turn the ignition switch off
Disconnect the battery cable from the negative terminal.
Check the terminals and connectors of the steering angle sensor for
damage, bend and loose connection
(unit side and connector side).
Is the inspection result ...
