C1312

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1311/11-C1314/14: Open in Main Relay 1 Circuit

DTC C1311/11 - Open in Main Relay 1 Circuit

DTC C1312/12 - Short in Main Relay 1 Circuit

DTC C1313/13 - Open in Main Relay 2 Circuit

DTC C1314/14 - Short in Main Relay 2 Circuit

DESCRIPTION

The main relay 1 supplies power to the changeover solenoid and the linear solenoid.
The main relay remains ON for approximately 2 minutes after the power switch is turned off and the input of brake operation signals stops, and supplies power to the system to keep it ready to operate.






WIRING DIAGRAM














INSPECTION PROCEDURE
NOTICE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.

PROCEDURE

1. INSPECT ABS MAIN FUSE




(a) Remove the ABS MAIN NO. 1, ABS MAIN NO. 2 and ABS MAIN NO. 3 fuses from the engine room R/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS MAIN FUSE
OK -- Continue to next step.
2. PERFORM ACTIVE TEST USING TECHSTREAM (ABS MAIN RELAY)
(a) Install the ABS MAIN NO. 1, ABS MAIN NO. 2 and ABS MAIN NO. 3 fuses.
(b) Connect Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Select the Active Test mode on Techstream.

ABS / VSC / TRAC:





*: Electronically Controlled Brake
(e) Check the operating sound of the ABS main relay when operating it with Techstream.
OK:
The operating sound of the ABS main relay should be heard.
OK -- INSPECT SKID CONTROL ECU (BS TERMINAL)
NG -- Continue to next step.
3. INSPECT ABS MAIN RELAY (ABS NO. 1, 2 RELAY)




(a) Turn the power switch off.
(b) Remove the ABS NO. 1 relay and ABS NO. 2 relay.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS MAIN RELAY (ABS NO. 1, 2 RELAY)
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU (+BI TERMINAL)




(a) Install the ABS NO. 1 relay and ABS NO. 2 relay.
(b) Disconnect the skid control ECU connectors.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BI CIRCUIT)
OK -- Continue to next step.
5. INSPECT SKID CONTROL ECU (RELAY TERMINAL)




(a) Reconnect the skid control ECU connectors.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE SKID CONTROL ECU
OK -- Continue to next step.
6. INSPECT SKID CONTROL ECU (BS TERMINAL)




(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)
OK -- Continue to next step.
7. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch on (IG).
(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:






B -- REPLACE SKID CONTROL ECU
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)