C1379

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1379: Downhill Assist Control Switch Malfunction (Test Mode DTC)
C1379 - Downhill Assist Control Switch Malfunction (Test Mode DTC)

DESCRIPTION

w/ Downhill Assist Control:

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

w/ Crawl Control:

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





WIRING DIAGRAM









INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform calibration Programming and Relearning.

PROCEDURE

1. CONFIRM VEHICLE SPECIFICATIONS

(a) Confirm the vehicle specifications.

Result





B -- CHECK CAN BUS
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (DOWNHILL ASSIST CONTROL SW)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(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 downhill assist control switch.

ABS/VSC/TRAC





OK:

The Techstream displays ON or OFF according to downhill assist control switch operation.

NG -- INSPECT DOWNHILL ASSIST CONTROL SWITCH (COMBINATION SWITCH)
OK -- Continue to next step.

3. CHECK TEST MODE DTC

(a) Perform the downhill assist control switch check in the Test Mode Procedure Test Mode Procedure.

OK:

Test mode DTC C1379 is cleared.

NG -- REPLACE MASTER CYLINDER SOLENOID Disassembly

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

4. INSPECT DOWNHILL ASSIST CONTROL SWITCH (COMBINATION SWITCH) Downhill Assist Control Indicator Light does not Come ON

NG -- REPLACE COMBINATION SWITCH ASSEMBLY Removal
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - DOWNHILL ASSIST CONTROL SWITCH)

(a) Disconnect the A7 skid control ECU connector.

(b) Disconnect the i5 combination switch connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MASTER CYLINDER SOLENOID Disassembly

6. CHECK CAN BUS

(a) Check that there are no problems with the CAN communication system Diagnosis System.

NG -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting
OK -- Continue to next step.

7. READ VALUE USING TECHSTREAM (CRAWL CONTROL SWITCH)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / D-SEAT SW / Data List.

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

D-SEAT SW





OK:

The Techstream displays according to crawl control switch operation.

NG -- CHECK HARNESS AND CONNECTOR (CRAWL CONTROL SWITCH - DRIVING SUPPORT SWITCH CONTROL ECU)
OK -- Continue to next step.

8. CHECK TEST MODE DTC

(a) Perform the crawl control switch check in the Test Mode Procedure Test Mode Procedure.

OK:

Test mode DTC C1379 is cleared.

NG -- REPLACE MASTER CYLINDER SOLENOID Disassembly

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

9. CHECK HARNESS AND CONNECTOR (CRAWL CONTROL SWITCH - DRIVING SUPPORT SWITCH CONTROL ECU)

(a) Disconnect the i5 combination switch connector.

(b) Disconnect the G60 driving support switch control ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

10. INSPECT CRAWL CONTROL SWITCH (COMBINATION SWITCH)

(a) Remove the combination switch Removal.

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





Standard Resistance:





Text in Illustration





NG -- REPLACE COMBINATION SWITCH ASSEMBLY Removal

OK -- REPLACE DRIVING SUPPORT SWITCH CONTROL ECU Removal