DTC C1441: Performance Decline of Brake Function: Procedure

1. Interview the customer to check if the pedals were depressed simultaneously while driving or braking.

   OK

   The pedals were not depressed simultaneously.

   HINT: 

   The skid control ECU may store this DTC upon judging that a stuck on malfunction has occurred when the accelerator pedal and brake pedal are depressed simultaneously.

   If the pedals were depressed simultaneously, clear the DTC because it is not a malfunction.

NG → END 

OK: Go to next step 

1. Check and record DTCs and Freeze Frame Data. Refer to DTC CHECK / CLEAR and. Refer to FREEZE FRAME DATA ).

   HINT: 

   Read Freeze Frame Data at the time DTC C1441 was stored, go to operation history and confirm the operating conditions.

   When reading Freeze Frame Data to confirm operating conditions, the following items can be confirmed: "F# or R# Wheel Speed", "Vehicle Speed", "Real Engine Torque" and "Accelerator Opening Angle %".

NEXT: Go to next step 

1. Clear the DTCs and Freeze Frame Data. Refer to DTC CHECK / CLEAR and. Refer to FREEZE FRAME DATA ).

NEXT: Go to next step 

1. Based on the customer problem analysis, confirm the brake pedal condition at the time the brake pedal was operated.

   Result

   Result	Proceed to
   The brake pedal is hard to depress.	A
   The brake pedal is extremely easy to depress.	B
   Neither of the above conditions. (Problem symptom does not occur.)	C

B → See step   6 

C → See step   7 

A: Go to next step 

1. Check the brake booster assembly. Refer to ON-VEHICLE INSPECTION .

   Result

   Result	Proceed to
   The brake booster assembly is abnormal.	A
   The brake booster assembly is normal.	B

   HINT: 

   If the result shows that the brake booster assembly is defective, check the related components such as the brake booster, brake vacuum check valve, check valve grommet, brake booster gasket, vacuum hose and intake system for vacuum leaks or clogs.

B → See step   7 

A → INSPECT RELATED COMPONENTS (FOR VACUUM LEAKS OR CLOGS) 

1. Check that the brake fluid level is sufficient.

   HINT: 

   • If the fluid level drops, check for a fluid leaks, and repair as necessary.
   • Check for brake fluid leakage. (brake master cylinder, brake line, flexible hose, brake actuator, wheel cylinders, etc.)

   Result

   Result	Proceed to
   Brake fluid level is not proper.	A
   Brake fluid level is proper.	B

   HINT: 

   If brake fluid leaks are not found in components such as the brake master cylinder, brake line, flexible hose, brake actuator or wheel cylinders but the fluid level has become lower, the brake master cylinder may be leaking internally. Therefore, replace the brake master cylinder and check brake pedal operation again.

B → See step   7 

A → CHECK AND REPAIR BRAKE FLUID LEAKS 

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Start the engine.
3. Perform a road test.
   NOTE:

   Do not intentionally stop the engine when driving. DTC C1441 will be stored if the brake pedal is depressed when moving the vehicle with the engine not running and the engine switch on (IG).

4. Check if the same DTC is recorded. Refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC C1441 is not output.	A
   DTCs C1441 and other DTC are output.	B
   Only DTC C1441 is output.	C

   HINT: 

   If DTC C1441 and other DTCs are output simultaneously, the other DTCs may have caused the engine to malfunction, resulting in DTC C1441 to be output. Read Freeze Frame Data to confirm malfunctioning parts and repair the applicable part.

   When reading Freeze Frame Data to confirm malfunctioning parts, the following items can be confirmed: "F# or R# Wheel Speed", "Vehicle Speed", "Real Engine Torque" and "Accelerator Opening Angle %".

B → CHECK AND REPAIR APPLICABLE PART 

C → See step   8 

A → END 

1. Check that the match marks on the adjustment part of the brake pedal load sensing switch are aligned with the match marks on the bracket, nut, adjusting screw, etc.
   Fig 1: Checking Brake Pedal Load Sensing Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   The match marks on the adjustment part of the brake pedal load sensing switch are aligned with the match marks on the bracket, nut, adjusting screw, etc.

NG → See step   10 

OK → See step   9