LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2004 >> Tundra Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 471 (Brakes - Abs With EBD & BA & TRAC & VSC (Diagnostics)) >> Abs With EBD & BA & TRAC & VSC System >> Circuit Inspection >> DTC C1256/56: Accumulator Low Pressure Malfunction >> Inspection Procedure

Inspection Procedure

WARNING: This page is about a different car, the 2006 Toyota Tundra and 2005 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: When replacing the master cylinder solenoid, perform zero point CALIBRATION  .

HINT:

When C1251/51, C1253/53, or C1254/54 is output together with C1256/56, inspect and repair the trouble area indicated by C1251/51, C1253/53, or C1254/54 first.

  1. Reconfirm DTC (See  DTC CHECK / CLEAR   ). 

    PREPARATION: 

    1. Clear the DTCs.
    2. Turn the ignition switch OFF.
    3. Depress the brake pedal more than 20 times.
    4. Turn the ignition switch to the ON position.
    5. Wait for 99 seconds.

    CHECK: 

    Check if the same DTCs are detected.

    RESULT: 

    DTC OUTPUT RESULT

    DTC is output A
    DTC is not output B
    1. B : END. 

      HINT:

      Excessive brake pedal operation results in abnormal accumulator pressure consumption. This is normal.

    2. A : Go to next step. 
  2. Check hydraulic circuit. 

    CHECK: 

    Perform hydraulic brake booster on-vehicle inspection (see HYDRAULIC BRAKE BOOSTER (W/VSC) ).

    OK: 

    Hydraulic circuit is normal (No leakage). 

    1. NG : Check and repair hydraulic circuit (See  CHECK FOR FLUID LEAKAGE  ). 
    2. OK : Go to next step. 
  3. Check value of the accumulator pressure sensor. 

    PREPARATION: 

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Select DATA LIST mode on the hand-held tester.
    DATA LIST MODE REFERENCE

    Item Measurement Item/Range (Display) Normal Condition Diagnostic Note
    ACC PRESS Accumulator Sensor/ min.: 0 V, max.: 5 V 3.58 V to 5 V If the value is constant regardless of pump operation, accumulator pressure sensor malfunction is suspected.

    CHECK: 

    Check that the accumulator pressure sensor output is normal.

    OK: 

    Accumulator pressure sensor value is normal. 

    1. NG : Replace master cylinder solenoid (See  DISASSEMBLY  ). 
    2. OK : Go to next step. 
  4. Reconfirm DTC (See  DTC CHECK / CLEAR   ). 

    PREPARATION: 

    Clear the DTCs.

    CHECK: 

    Check if the same DTCs are detected.

    RESULT: 

    DTC OUTPUT RESULT

    DTC is output A
    DTC is not output B
    1. B : END. 
    2. A : Replace master cylinder solenoid (See  DISASSEMBLY  ). 
scientia non olet · About LEMON Manuals