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:
Diagnosis and repair work flow
Work Flow
OVERALL SEQUENCE
DETAILED FLOW
1.COLLECT INFORMATION FROM THE CUSTOMER
Get detailed information from the customer about the symptom
(the condition and the environment when the
incident/malfunction occurred) using the diagnostic worksheet. Refer to BRC-52,
"Diagnostic Wor ...
Electric ignition system
ELECTRIC IGNITION SYSTEM : System Description
SYSTEM DIAGRAM
*1: CVT models
*2: M/T models
Input/output signal chart
Sensor
Input Signal to ECM
ECM function
Actuator
Crankshaft position sensor (POS)
Engine speed*3
Piston position
Ignition ...
C1140 Actuator relay system
DTC Logic
DTC DETECTION LOGIC
DTC
Display Item
Malfunction detected condition
Possible causes
C1140
ACTUATOR RLY
When a malfunction is detected in actuator relay.
Harness or connector
ABS actuator and electric unit
(control unit)
Fusible link ...
