Nissan Armada 2025-2026 Service and Repair Manual: Trailer Towing System

Precautions

Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER"

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collision.

Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this Service Manual.

WARNING:

Always observe the following items for preventing accidental activation.

• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in the event of a collision that would result in air bag inflation, it is recommended that all maintenance and repair be performed by an authorized NISSAN/INFINITI dealer.

• Improper repair, including incorrect removal and installation of the SRS, can lead to personal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag Module, see “SRS AIR BAG”.

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

PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS

WARNING:

Always observe the following items for preventing accidental activation.

• When using air or electric power tools or hammers, always switch the ignition/power switch OFF, disconnect the 12V battery or batteries, and wait at least 3 minutes before performing any service.

Precautions for Removing Battery Terminal

• When disconnecting the 12V battery terminal, turn off the ACC power before disconnecting the 12V battery terminal, observing “How to disconnect 12V battery terminal” described below.

  

  NOTE:

  Some ECUs operate for a certain fixed time even after ignition switch is turned OFF and ignition power supply is stopped. If the battery terminal is disconnected before ECU stops, accidental DTC detection or ECU data damage may occur.

• For Nissan Armada vehicles with the 2-batteries, be sure to connect the main battery and the sub battery before turning ON the ignition switch.

  NOTE:

  If the ignition switch is turned ON with any one of the terminals of main battery and sub battery disconnected, then DTC may be detected.

• After installing the 12V battery, always check "Self Diagnosis Result" of all ECUs and erase DTC.

  NOTE:

  The removal of 12V battery may cause a DTC detection error.

HOW TO DISCONNECT 12V BATTERY TERMINAL

Disconnect 12V battery terminal according to instruction described below.

1. Open the hood.

2. Turn ignition switch to the ON position.

3. Turn ignition switch to the OFF position with the driver side door opened.

4. Get out of the vehicle and close the driver side door.

5. Wait at least 3 minutes. For vehicle with the engine listed below, remove the battery terminal after a lapse of the specified time.

   BR08DE	: 4 minutes	R9N engine	: 12 minutes
   BR10DE	: 12 minutes	V9X engine	: 4 minutes
   D4D engine	: 20 minutes	YD25DDTi	: 2 minutes
   HR09DET	: 12 minutes	YS23DDT	: 4 minutes
   HR10DDT	: 12 minutes	YS23DDTT	: 4 minutes
   HR10DET	: 12 minutes	ZD30DDTi	: 60 seconds
   HR13DDT	: 12 minutes	ZD30DDTT	: 60 seconds
   HRA2DDT	: 12 minutes	K9K engine	: 4 minutes
   M9R engine	: 4 minutes	R9M engine	: 4 minutes

   CAUTION:

   While waiting, never operate the vehicle such as locking, opening, and closing doors. Violation of this caution results in the activation of ACC power supply according to the Auto ACC function.

6. Remove 12V battery terminal.

   CAUTION:

   After installing 12V battery, always check self-diagnosis results of all ECUs and erase DTC.

Trailer Brake Does Not Operate Normally

Not Operated in All Operation

Diagnosis Procedure

CHECK SYMPTOM

Check symptom (A or B)

Symptom
A	Display does not turn ON
B	Display is normal

Which symptom is detected?

A>>

GO TO 2.

B>>

GO TO 3.

CHECK POWER SUPPLY AND GROUND CIRCUIT

Check power supply and ground circuit. Refer to Diagnosis Procedure.

Is the inspection result normal?

YES>>

Replace trailer brake control unit. Refer to Removal and Installation.

NO>>

Repair or replace the malfunctioning parts.

CHECK TRAILER BRAKE OUTPUT SIGNAL CIRCUIT

Check trailer brake output signal circuit. Refer to Diagnosis Procedure.

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

Repair or replace the malfunctioning parts.

CHECK INTERMITTENT INCIDENT

Refer to Intermittent Incident.

>>

INSPECTION END

Not Operated When Brake Pedal Is Depressed

Diagnosis Procedure

CHECK STOP LAMP INPUT/OUTPUT SIGNAL CIRCUIT

Check stop lamp input/output signal circuit. Refer to Diagnosis Procedure.

Is the inspection result normal?

YES>>

Replace trailer brake control unit. Refer to Removal and Installation.

NO>>

Repair or replace the malfunctioning parts.

Not Operated When Manual Control Lever Is Operated

Diagnosis Procedure

REPLACE TRAILER BRAKE CONTROL UNIT

Replace trailer brake control unit. Refer to Removal and Installation.

>>

INSPECTION END

Stop Lamp and High-Mounted Stop Lamp Does Not Turn on When Manual Control Lever Is Operated

Diagnosis Procedure

CHECK STOP LAMP INPUT/OUTPUT SIGNAL CIRCUIT

Check stop lamp input/output signal circuit. Refer to Diagnosis Procedure.

Is the inspection result normal?

YES>>

Replace trailer brake control unit. Refer to Removal and Installation.

NO>>

Repair or replace the malfunctioning parts.

Trailer Brake Control Unit

Removal and Installation

REMOVAL

Remove instrument pad B. Refer to Removal and Installation.

Remove fixing screws and then remove trailer brake control unit.

INSTALLATION

Install in the reverse order of removal.