Nissan Sentra B18 (2020-2025) Service Manual: U0077-00 Can Comm Circuit

Dtc Description

DTC Description

CAN COMMUNICATION

CAN (Controller Area Network) is a serial communication line for real time applications. It is an on-Nissan Sentra vehicle multiplex communication line with high data communication speed and excellent error detection ability. Modern Nissan Sentra vehicle is equipped with many electronic control units, 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, CAN-L) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads the required data only.

CAN communication signal chart. CAN Communication Signal Chart

DTC DETECTION LOGIC

DTC		CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
U0077	00	Control module comm Bus E Off (Control module communication Bus E Off)	Diagnosis condition	When engine is running When AEB system is ON
			Signal (terminal)	CAN communication signal
			Threshold	If ADAS control unit 2 is not transmitting or receiving CAN communication signal
			Diagnosis delay time	2 seconds or more

Note:

If “U0077-00” is detected, first diagnose the CAN communication system.

POSSIBLE CAUSE

CAN communication system

FAIL-SAFE

The following systems are canceled.

• Nissan Sentra Vehicle-to-vehicle distance control mode

• Conventional (fixed speed) cruise control mode

• AEB

• LDW

• TSR

• BSW

• I-DA

• RCTA

• I-FCW

• RAB

Note:

With the detection of “U0077-00” some systems do not perform the fail-safe operation. A system controlling based on a signal received from the control unit performs fail-safe operation when the communication with the ADAS control unit 2 becomes inoperable.

Confirmation Procedure

Confirmation Procedure

1. PERFORM DTC CONFIRMATION PROCEDURE

   1. Start the engine.

   2. Turn the AEB system ON.

   3. Perform “All DTC Reading” with CONSULT.

   4. Check if the “U0077-00” is detected as the current malfunction in “Self Diagnostic Result” of “ICC/ADAS 2”.

   Is “U0077-00” detected as the current malfunction?

   YES >>

   DTC Diagnosis Procedure

   NO-1 >>

   To check malfunction symptom before repair: Intermittent Incident

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

DTC Diagnosis Procedure

1. PERFORM THE SELF-DIAGNOSIS

   1. Turn the ignition switch ON.

   2. Turn the AEB system ON, and then wait for 30 seconds or more.

   3. Perform “All DTC Reading” with CONSULT.

   4. Check if the “U0077-00” is detected as the current malfunction in “Self Diagnostic Result” of “ICC/ADAS 2”.

   Is “U0077-00” detected as the current malfunction?

   YES >>

   Trouble Diagnosis Flow Chart

   NO >>

   INSPECTION END