Home

Toyota Workshop

GSIC - Global Service Information Center

DTC    C1A41    Brake Request Value Mismatch between ENG / EHV and Driving Support ECU

for Preparation Click here


DESCRIPTION

The brake booster with master cylinder (skid control ECU) receives brake control request signals from the power management control ECU and driving support ECU.
When the request signals received from the power management control ECU and driving support ECU are not consistent, the brake booster with master cylinder (skid control ECU) determines that a malfunction has occurred and sends a malfunction signal to the driving support ECU.

DTC Code
DTC Detection Condition
Trouble Area
C1A41
While power switch is on (IG), brake request signal from power management control ECU and driving support ECU are inconsistent for 1 second
  1. Electronically controlled brake system
  2. Hybrid control system
  3. Power management control ECU
  4. Brake booster with master cylinder (skid control ECU)
  5. Driving support ECU

WIRING DIAGRAM

Refer to DTC C1A50 (Click here).

INSPECTION PROCEDURE

1.READ OUTPUT DTC (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

  1. Enter the following menus: Chassis / ABS/VSC/TRC / DTC.

  1. Read the DTCs.

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



B
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM (Click here)
A


2.READ OUTPUT DTC (HYBRID CONTROL SYSTEM)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

  1. Enter the following menus: Powertrain / Hybrid Control / DTC.

  1. Read the DTCs.

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



B
GO TO HYBRID CONTROL SYSTEM (Click here)
A


3.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A41)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A41 is output
    		B



B
Go to step 4
A

USE SIMULATION METHOD TO CHECK (Click here)  

4.REPLACE DRIVING SUPPORT ECU

  1. Replace the driving support ECU (Click here).


NEXT


5.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A41)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A41 is output
    		B



B
Go to step 6
A

END 

6.REPLACE BRAKE BOOSTER WITH MASTER CYLINDER

  1. Replace the brake booster with master cylinder (skid control ECU) (Click here for LHD, Click here for RHD).


NEXT


7.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A41)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A41 is output
    		B



B
REPLACE POWER MANAGEMENT CONTROL ECU (Click here)
A

END