Toyota Tundra Service Manual: Parking Brake Switch Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) detects the condition of the parking brake switch assembly.

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM

(a) Using the Techstream, read the Data List.

Click here

Main Body

Tester Display

Measurement Item / Range

Normal Condition

Diagnostic Note

Parking Brake SW

Parking brake switch assembly signal / OFF or ON

OFF: Parking brake switch off

ON: Parking brake switch on

-

OK:

Normal condition listed above are displayed.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

INSPECT PARKING BRAKE SWITCH ASSEMBLY

(a) Remove the parking brake switch assembly.

Click here

(b) Inspect the parking brake switch assembly.

Click here

NG

REPLACE PARKING BRAKE SWITCH ASSEMBLY

OK

3.

CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - PARKING BRAKE SWITCH ASSEMBLY)

(a) Disconnect the 3H driver side junction block assembly connector.

(b) Disconnect the A5 parking brake switch assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3H-18 - A5-1

Always

Below 1 Ω

3H-18 or A5-1 - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK DRIVER SIDE JUNCTION BLOCK ASSEMBLY

(a) Remove the driver side junction block assembly.

Click here

*a

Component without harness connected

(Driver Side Junction Block Assembly)

(b) Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly.

Click here

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3H-18 - A-12 (PKB)

Always

Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    Operation Check

    Parts Location

    See More:

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