Description

Description

CAUTION:

• Never use electrical test equipment on any circuit related to the SRS unless instructed in this Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or harness connectors.

• Never repair, splice or modify the SRS wiring harness. If the harness is damaged, replace it with a new one.

• Keep ground portion clean.

DIAGNOSIS FUNCTION

• The SRS self-diagnostic results can be read with air bag warning lamp and/or CONSULT.

• The user mode is exclusively prepared for the customer (driver). This mode warns the driver of a system malfunction through the operation of the air bag warning lamp.

• The diagnosis mode allows the technician to locate and inspect the malfunctioning part.

• The mode applications for the air bag warning lamp and CONSULT are as per the following items:

  ×: Application, —: Not application

  Diagnosis tool	User mode	Diagnosis mode
  Air bag warning lamp	×	×
  CONSULT	–	×

On Board Diagnosis Function

On Board Diagnosis Function

ON-BOARD DIAGNOSIS

There are two self diagnosis functions with air bag warning lamp per the following items:

• USER MODE

• DIAGNOSIS MODE

METHOD OF STARTING

• Diagnosis mode changes from user mode to diagnosis mode when changing operation is performed.

• In user mode, when SRS air bag warning lamp is not turning ON, changing to diagnosis mode by ignition switch operation is not possible.

• In diagnosis mode, when repair is complete and system is normal, the mode changes to user mode when ignition switch is OFF to ON.

Procedure to Change Diagnosis Mode

1. Ignition switch from OFF to ON.

2. SRS air bag lamp turns ON for 7 second and turns OFF, then ignition switch OFF within 2 second after the lamp turns OFF.

   Note:

   When in Diagnosis Mode, the air bag warning lamp may illuminate for more than 7 seconds after the ignition switch is ON. If this is the case, the ignition switch must still be cycled OFF after 7 seconds.

3. After ignition switch OFF, wait for 3 seconds or more.

4. Repeat operation 1 to 3 for 2 times so that operation 1 to 3 is repeated for 3 times in total.

5. Ignition switch from OFF to ON. Diagnosis mode changes.

USER MODE

In USER MODE, air bag warning lamp on combination meter turning ON when a malfunction is detected and warns the customer (driver).

How to Read Air Bag Warning Lamp

1. Ignition switch from OFF to ON, and check that the air bag warning lamp turns ON.

2. Compare the air bag warning lamp operation pattern with the examples.

   Air Bag Warning Lamp Examples:

   Air bag warning lamp flashing pattern (User Mode)

   Warning lamp	SRS condition	Reference item
   	No malfunction is detected. No further action is necessary.	—
   	The system is malfunctioning and needs to be repaired.	Refer to Trouble Diagnosis with CONSULT or Trouble Diagnosis without CONSULT.
   	Zero point reset is incomplete	Refer to Special Repair Requirement.
   	Air bag is deployed. Seat belt pre-tensioner is deployed.	Refer to For Frontal Collision or For Side and Rollover Collision.
   	Air bag diagnosis sensor unit is malfunctioning. Air bag power supply circuit is malfunctioning. SRS air bag warning lamp circuit is malfunctioning.	Refer to Diagnosis Procedure.
   	Air bag diagnosis sensor unit is malfunctioning. Air bag warning lamp circuit is malfunctioning.	Refer to Diagnosis Procedure.

Trouble Diagnosis with Consult

Trouble Diagnosis with CONSULT

CONSULT

DTC is displayed on “Self Diagnostic Result”.

Note:

If a malfunction is not detected on “Self Diagnostic Result [CURRENT]”, but a malfunction is detected during SRS Operation Check, the following cases may exist:

• “Self Diagnostic Result [PAST]” memory might not be erased. Refer to SRS Final Check.

• SRS system malfunctions intermittently. Refer to Inspection Procedure.

Trouble Diagnosis Without Consult

Trouble Diagnosis without CONSULT

DIAGNOSIS MODE

Note:

Diagnosis Mode can not be entered if a malfunction is not detected in User Mode.

CONSULT

1. Ignition switch ON.

2. After AIR BAG warning lamp lights for 7 seconds, ignition switch OFF within 1 second.

3. Wait more than 3 seconds.

4. Repeat steps 1 to 3 two more times (3 times total).

5. Ignition switch ON.

SRS is now in Diagnosis Mode. Refer to Flash Code Index.

Srs History Check

SRS History Check

SRS HISTORY CHECK

1. Check repair history of the SRS. If no repairs have been made, perform On Board Diagnosis Function. If repairs have been made, GO TO step 2.

2. Erase ”Self Diagnostic Result [PAST]” after repair. Refer to SRS Final Check.

Srs Final Check

SRS Final Check

DIAGNOSIS MODE

CONSULT

1. Confirm that zero point reset of OCS is complete.

2. If no DTCs are detected on “Self Diagnostic Result [CURRENT]”, repair of SRS is completed. Go to step 3.

   If any DTCs are detected on “Self Diagnostic Result [CURRENT]”, the malfunction has not been repaired completely or another malfunction is being detected. Perform SRS Operation Check again. Refer to On Board Diagnosis Function.

3. Select “ERASE”.

   Note:

   Selecting “ERASE” will clear the SRS memory of the malfunction (“Self Diagnostic Result [PAST]”). If “Self Diagnostic Result [PAST]” is not erased, User Mode may show the previous system malfunction even if the malfunction has been repaired completely.

4. Check that no malfunction is detected in “Self Diagnostic Result [PAST]”.

5. Exit Diagnosis Mode and disconnect the CONSULT.

6. Perform SRS Operation Check. Refer to On Board Diagnosis Function.

Consult Function (air Bag)

CONSULT Function (AIR BAG)

CONSULT performs the following functions:

Diagnosis mode	CGW Status			Description
	Restricted Mode	Diag Test Mode	Open Mode
Self Diagnostic Result	Display	Display	Display	Display non-network DTC which air bag diagnosis sensor unit memorizes
CGW Information	Display	Display	Display	Display the current CGW mode Enables CGW to switch mode
Data Monitor	Display	Display	Display	This item is displayed, but cannot be supported.
ECU Identification	Display	Display	Display	Air bag diagnosis sensor unit part number is displayed.
TROUBLE DIAG RECORD	Display	Display	Display	With TROUBLE DIAG RECORD, diagnosis results previously erased by a reset operation can be displayed on CONSULT screen.
Configuration*	Display	Display	Display	Read and save the Nissan Sentra vehicle specification.
Network-DTC*	Display	Display	Display	Display network DTC which air bag diagnosis sensor unit memorizes when performing "Diagnosis (All System)".

^*: Displays when performing "Diagnosis (All System)".

SELF DIAGNOSTIC RESULT

Refer to DTC Index.

FREEZE FRAME DATA (FFD)

The air bag diagnosis sensor unit records the following Nissan Sentra vehicle condition at the time a particular DTC is detected, and displays on CONSULT.

CONSULT screen item	Indication/Unit	Description
ODO/TRIP METER	km	Total mileage (Odometer value) of the moment a particular DTC is detected.
DTC count	—	DTC detection number of times.

CGW INFORMATION

Display the diagnosis mode which a user can perform in Diag Test mode/Open Mode by switching the CGW status from Restricted mode to Diag Test Mode/Open Mode.

For the method of switching CAN Gateway status. Refer to CONSULT Function.

Consult Function (occupant Detection)

CONSULT Function (OCCUPANT DETECTION)

APPLICATION ITEM

CONSULT performs the following functions:

Diagnosis mode	CGW Status			Description
	Restricted Mode	Diag Test Mode	Open Mode
CGW Information	Display	Display	Display	Display the current CGW mode Enables CGW to switch mode
Data Monitor	Display	Display	Display	Displays the real-time input signal of occupant detection system control unit.
Work support	Non-display	Non-display	Display	This mode enables a technician to adjust some devices faster and more accurately by following the indications on the CONSULT.

CGW INFORMATION

Display the diagnosis mode which a user can perform in Diag Test mode/Open Mode by switching the CGW status from Restricted mode to Diag Test Mode/Open Mode.

For the method of switching CAN Gateway status. Refer to CONSULT Function.

DATA MONITOR

Note:

The following table includes information (items) inapplicable to this Nissan Sentra vehicle. For information (items) applicable to this vehicle, refer to CONSULT display items.

Monitor Item	Description
Buckle Switch Status [Not Moni/Unfasten/Fasten/Reload]	The switch status input from front seat belt buckle switch RH. Not Moni: Front seat belt buckle switch RH is not monitored. Unfasten: Front seat belt buckle switch RH is unfasten. Fasten: Front seat belt buckle switch RH is fasten. Reload: The front seat belt buckle switch RH state is loading.
Buckle Switch Spec [Not Moni/Nor Op/Nor Cl/Frm ACU]	Displays the spec of the front seat belt buckle switch RH. Not Moni: Front seat belt buckle switch RH is not monitored. Nor Op: Front seat belt buckle switch RH is normal open type. Nor Cl: Front seat belt buckle switch RH is normal close type. Frm ACU: Occupant detection system control unit receives front seat belt buckle switch RH signal from air bag diagnosis sensor unit.
Buckle Switch Status (Comm) [Not Moni/Moni(wir)/Frm ACU]	Displays the status of the front seat belt buckle switch RH signal. Not Moni: Front seat belt buckle switch RH is not monitored. Moni(wir): The switch status input from front seat belt buckle switch RH. Frm ACU: The switch status input from air bag diagnosis sensor unit.

WORK SUPPORT

Diagnostic Test Mode	Diagnostic Item	Description
Work support	Zero point reset function	Perform zero point reset. Refer to Special Repair Requirement.