Nissan Sentra Service Manual: DTC/Circuit diagnosis
U0073 COMMUNICATION BUS A OFF
DTC Logic
DTC DETECTION LOGIC
| DTC | CONSULT screen terms (Trouble diagnosis content) | DTC detection condition | Possible causes |
| U0073 | COMM BUS A OFF (Control Module Communication Bus A Off) | TCM communication blockage lasts for 2 seconds or more when turning ON the ignition switch. (Communication not established.) | Harness or connector (CAN communication line is error) |
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.PERFORM DTC CONFIRMATION PROCEDURE
- Start the engine and wait for at least 5 seconds.
- Check the DTC.
Is “U0073” detected? YES >> Go to TM-152, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
For the diagnosis procedure, refer to LAN-16, "Trouble Diagnosis Flow Chart".
U0100 LOST COMMUNICATION (ECM A)
DTC Logic
DTC DETECTION LOGIC
| DTC | CONSULT screen terms [Trouble diagnosis content] | DTC detection condition | Possible causes |
| U0100 | LOST COMM (ECM A) [Lost Communication With ECM/PCM A] | When the ignition switch is ON, TCM is unable to receive the CAN communications signal from ECM continuously for 2 seconds or more. |
|
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.PERFORM DTC CONFIRMATION PROCEDURE
- Start the engine and wait for at least 5 seconds.
- Check the DTC.
Is “U0100” detected? YES >> Go to TM-153, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
For the diagnosis procedure, refer to LAN-16, "Trouble Diagnosis Flow Chart".
Basic inspection
DIAGNOSIS AND REPAIR WORK FLOW
Work Flow
NOTE:
“DTC” includes DTC at the 1st trip.
1.OBTAIN INFORMATION ABOUT SYMPTOM
Refer to TM-140, "Diagnostic Work Sheet" and interview t ...
U0140 Lost communication (BCM)
DTC Logic
DTC DETECTION LOGIC
DTC
CONSULT screen terms
[Trouble diagnosis content]
DTC detection condition
Possible causes
U0140
LOST COMM (BCM)
[Lost Communication ...
Other materials:
Rear window defogger and door mirror defoggers do not operate
Diagnosis procedure
Regarding Wiring Diagram information, refer to DEF-20, "Wiring Diagram".
1. Check rear window defogger switch
Check rear window defogger switch.
Refer to def-30, "component function check".
Is the inspection result normal?
Yes >> go to 2.
No ...
Diagnosis system (bcm) (with intelligent key system)
Common item
Common item : consult function (bcm - common item)
Application item
Consult performs the following functions via can communication with bcm.
Direct diagnostic mode
Description
ECU identification
The BCM part number is displayed.
Self diagnostic result
...
Diagnosis description : system readiness
test (SRT) code
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/ISO
15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M),
certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major
emission s ...
