ELECTRONICALLY CONTROLLED BRAKE SYSTEM Brake Control Warning Light Remains ON

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.

If the skid control ECU stores a DTC, the brake warning light / yellow (minor malfunction) comes on in the combination meter assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

   
   

   1. Check if CAN communication system DTCs are output Click here.

      Result
      Result Proceed to DTC is not output. A DTC is output. B

   
   

   B

   INSPECT CAN COMMUNICATION SYSTEM Click here

   A

2. CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

   
   

   1. Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.

      OK
      The connector is securely connected.

   
   

   NG

   CONNECT CONNECTOR TO ECU CORRECTLY

   OK

3. CHECK AUXILIARY BATTERY

   
   

   1. Check the auxiliary battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition Auxiliary battery Power switch on (IG) 11 to 14 V Auxiliary battery Power switch on (READY) 11 to 15.5 V

   
   

   NG

   CHARGE OR REPLACE AUXILIARY BATTERY

   OK

4. INSPECT COMBINATION METER ASSEMBLY

   
   

   1. Perform the Active Test of the combination meter assembly (meter CPU) using the Techstream Click here.

   2. Check the combination meter assembly.

      OK
      The brake warning light / yellow (minor malfunction) turns on or off in accordance with Techstream operation.

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table refer back to the table and proceed to the next step before replacing the part Click here.

   
   

   NG

   REPLACE COMBINATION METER ASSEMBLY Click here

   OK

   REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here