Toyota Tacoma (2015-2018) Service Manual: While Alarm is Armed, Engine Hood is opened but Alarm does not Sound

DESCRIPTION

A situation in which the alarm is armed but does not sound when the hood is opened can be caused when the main body ECU (multiplex network body ECU) cannot detect whether the hood courtesy switch is open or closed.

If the alarm does not sound, there may be a malfunction in the hood courtesy switch, main body ECU (multiplex network body ECU) or a wire harness.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Registration (See page ).*1

PROCEDURE

(a) Close all doors and the hood.

(b) Lock the doors using the wireless operation*1, key linked operation or entry operation*2.

(c) Check that the security indicator light illuminates.

(d) After 30 seconds have elapsed, check that the security indicator light changes from illuminated to flashing.

HINT:

The illumination status of the security indicator light can be used to determine whether the theft deterrent system is set or unset.

NG

GO TO THEFT DETERRENT SYSTEM CANNOT BE SET OR UNSET

OK

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

OK:

The Techstream display changes correctly in response to the hood courtesy switch (hood lock assembly) status.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

(a) Remove the hood lock assembly (See page ).

(b) Inspect the hood lock assembly (See page ).

NG

REPLACE HOOD LOCK ASSEMBLY

OK

(a) Disconnect the E25 hood lock assembly connector.

(b) Disconnect the M6 main body ECU (multiplex network body ECU) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR