Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: Downhill Assist Control Switch Malfunction (Test Mode DTC) (C1379)

DESCRIPTION

DTC C1379 is cleared when the crawl control switch sends a crawl control operation signal or when test mode ends.

DTC Code

DTC Detection Condition

Trouble Area

C1379

Stored only during test mode.

  • Crawl control switch (drive monitor switch)
  • Harness or connector
  • Skid control ECU (master cylinder solenoid)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the skid control ECU (master cylinder solenoid), perform calibration (See page ). Inspect the fuses for circuits related to this system before performing ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

READ VALUE USING TECHSTREAM (CRAWL CONTROL SWITCH)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

(f) Check the Data List for proper functioning of the crawl control switch.

ABS/VSC/TRAC

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Crawl Control Switch

Crawl speed selector switch status/ LOW, MIDLOW, MID, MIDHIGH or HIGH

Actual crawl speed selector switch position

-

OK:

The Techstream displays according to crawl control switch operation.

NG

GO TO STEP 3

OK

2.

CHECK TEST MODE DTC

(a) Perform the crawl control switch check in the Test Mode Procedure (See page OK: OK: ).

OK:

Test mode DTC C1379 is cleared.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE MASTER CYLINDER SOLENOID

3.

INSPECT DRIVE MONITOR SWITCH

(a) Remove the crawl control switch (drive monitor switch) (See page (b) Inspect the crawl control switch (drive monitor switch) (See page ).

(b) Inspect the crawl control switch (drive monitor switch) (See page ).

NG

REPLACE DRIVE MONITOR SWITCH

OK

4.

INSPECT ROOF CONSOLE BOX ASSEMBLY

(a) Remove the roof console box assembly.

  • for Double Cab: (See page ) for Access Cab: (See page )
  • for Access Cab: (See page ) )
Text in Illustration

*a

Component without harness connected

(Roof Console Box Assembly)

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R44-1 (SWI3) - 2

Always

Below 1 Ω

R44-3 (DN) - 7

Always

Below 1 Ω

R44-4 (ECU) - 6

Always

Below 1 Ω

R44-5 (UP) - 3

Always

Below 1 Ω

R44-12 (GND) - 5

Always

Below 1 Ω

Result

Result

Proceed to

OK

A

NG (for Double Cab)

B

NG (for Access Cab)

C

A

REPAIR OR REPLACE HARNESS OR CONNECTOR (MASTER CYLINDER SOLENOID - ROOF CONSOLE BOX ASSEMBLY)

B

REPLACE ROOF CONSOLE BOX ASSEMBLY

C

REPLACE ROOF CONSOLE BOX ASSEMBLY

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