Lexus IS250 · Service Manual BRAKE

C1380/64

Diagnostic trouble codes

DESCRIPTION

Upon receiving the hill-start assist control (HAC) operating signal from the skid control ECU, the relay contact turns on and the stop light comes on.
DTC No.
 DTC Detection Condition
 Trouble Area
C1380/64
 When either of the following is detected:
  1. When the voltage at the IG1 terminal is between 10 to 14 V and the stop light control relay drive output (STPO) is ON, a signal has not been input to the STP terminal for 5 seconds or more.
  2. When the voltage at the IG1 terminal is between 10 to 14 V and the stop light control relay drive output (STPO) is OFF, the signal at the STP1 is different from the input signal at the STP2 for 5 seconds or more.
  1. STOP SW fuse
  2. Stop light switch
  3. Stop light switch circuit
  4. Stop light control relay (A/T)
  5. Stop light control relay circuit (A/T)
  6. Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM

C126456E01
C126457E01

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (Click here).

HINT:
When C1249/49 is output together with C1380/64, inspect and repair the trouble areas indicated by C1249/49 first.


1. INSPECT STOP SW FUSE

  1. C106592E05
    Remove the STOP SW fuse from the main body ECU RH.

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

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    STOP SW (7.5 A) fuse
    		 Always
    		 Below 1 Ω



NG
REPLACE STOP SW FUSE
OK


2. CHECK STOP LIGHT OPERATION

  1. Install the STOP SW fuse.

  1. Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

    OK:
    Condition
    		 Illumination Condition
    Brake pedal depressed
    		 ON
    Brake pedal released
    		 OFF



NG
INSPECT STOP LIGHT CIRCUIT
OK


3. INSPECT SKID CONTROL ECU (STP1 TERMINAL)

  1. F049362E35
    Disconnect the skid control ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    A14-27 (STP1) - Body ground
    		 Stop light switch ON (Brake pedal depressed)
    		 8 to 14 V
    A14-27 (STP1) - Body ground
    		 Stop light switch OFF (Brake pedal released)
    		 Below 1.5 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)
OK


4. INSPECT SKID CONTROL ECU (STP2 TERMINAL)

  1. F049362E37
    Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    A14-27 (STP1) - A14-21 (STP2)
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)
OK


5. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (STOP LIGHT CONTROL RELAY)

  1. Reconnect the skid control ECU connector.

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Select the Active Test mode on the intelligent tester.

    ABS / VSC: 
    Item (Display)
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Stop Lamp Relay
    		 Turns stop light control relay ON / OFF
    		 Stop light comes on (Does not come on for 5 seconds or more)

  1. Check that the "ON" and "OFF" of the stop light can be shown on the rear combination light by the intelligent tester.

    OK:
    The stop light turns on or off in accordance with the intelligent tester.



 OK
Go to step 9
NG


6. INSPECT STOP LIGHT CONTROL RELAY

  1. C126459E01
    Turn the engine switch off.

  1. Remove the stop light control relay.

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

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    3 - 4
    		 Always
    		 Below 1 Ω
    3 - 5
    		 Always
    		 10 kΩ or higher
    3 - 4
    		 When battery positive voltage is applied to terminal 1 and battery negative voltage to terminal 2
    		 10 kΩ or higher
    3 - 5
    		 When battery positive voltage is applied to terminal 1 and battery negative voltage to terminal 2
    		 Below 1 Ω



NG
REPLACE STOP LIGHT CONTROL RELAY
OK


7. INSPECT STOP LIGHT CONTROL RELAY (POWER SOURCE TERMINAL)

  1. C126481E01
    Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    Stop light control relay terminal 5 - Body ground
    		 Always
    		 8 to 14 V
    Stop light control relay terminal 2 - Body ground
    		 Engine switch on (IG)
    		 8 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK


8. INSPECT SKID CONTROL ECU (STPO TERMINAL)

  1. F049362E38
    Turn the engine switch off.

  1. Install the stop light control relay.

  1. Disconnect the skid control ECU connector.

  1. Turn the engine switch on (IG).

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    A14-16 (STPO) - Body ground
    		 Engine switch on (IG)
    		 10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (STPO CIRCUIT)
OK


9. RECONFIRM DTC

  1. Turn the engine switch off.

  1. Reconnect the skid control ECU connector.

  1. Clear the DTC (Click here).

  1. Check if the same DTC is recorded (Click here).

    Result:
    Condition
    		 Proceed to
    DTC (C1380/64) is not output
    		 A
    DTC (C1380/64) is output
    		 B



B
REPLACE BRAKE ACTUATOR ASSEMBLY
A

USE SIMULATION METHOD TO CHECK


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