| Last Modified: 11-20-2023 | 6.11:8.1.0 | Doc ID: RM1000000014VLN |
| Model Year Start: 2018 | Model: Camry HV | Prod Date Range: [07/2017 - 09/2018] |
| Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1256; Accumulator Low Pressure; 2018 MY Camry HV [07/2017 - 09/2018] | ||
|
DTC |
C1256 |
Accumulator Low Pressure |
DESCRIPTION
The accumulator pressure sensor is built into the brake actuator (brake booster with master cylinder assembly) and detects the accumulator pressure.
The skid control ECU (brake booster with master cylinder assembly) turns on the brake warning light / red (malfunction) and brake warning light / yellow (minor malfunction), and sounds the meter buzzer if it senses a decrease in the accumulator pressure.
DTC C1256 may be stored if the accumulator pressure drops due to frequent braking (this is not a malfunction).
|
DTC No. |
Detection Item |
INF Code |
DTC Detection Condition |
Trouble Area |
Note |
|---|---|---|---|---|---|
|
C1256 |
Accumulator Low Pressure |
341 1125 |
Significant drop in accumulator pressure continues. (DTCs will be stored and the buzzer will operate when either condition is met.) |
|
Electronically controlled brake system DTC |
WIRING DIAGRAM
Refer to DTCs C1252 and C1253.
Click here
![2018 MY Camry HV [07/2017 - 09/2018]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1252,C1253; Brake Booster Pump Motor on Time Abnormally Long+](/t3Portal/stylegraphics/info.gif)
CAUTION / NOTICE / HINT
NOTICE:
-
After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".
Click here
- Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
|
1. |
CHECK DTC |
(a) Clear the DTCs.
Chassis > ABS/VSC/TRAC > Clear DTCs
(b) Turn the power switch off.
(c) Turn the power switch on (IG).
(d) Check if the same DTC is output.
Chassis > ABS/VSC/TRAC > Trouble Codes
|
Result |
Proceed to |
|---|---|
|
DTC C1256 is output. |
A |
|
DTCs C1202, C1241, C1252, C1253 and/or C1391 are output. |
B |
| B |
|
|
|
2. |
INSPECT BRAKE BOOSTER PUMP ASSEMBLY |
|
(a) Turn the power switch off. |
|
(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.
OK:
The connector is securely connected.
(c) Disconnect the A45 brake booster pump assembly connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
2 (BM1) - 4 (GND1) |
Always |
10 Ω or less |
|
1 (BM2) - 3 (GND2) |
Always |
10 Ω or less |
|
2 (BM1) - 1 (BM2) |
Always |
Below 1 Ω |
|
4 (GND1) - 3 (GND2) |
Always |
Below 1 Ω |
| NG |
|
|
|
3. |
READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE) |
(a) Reconnect the A45 brake booster pump assembly connector.
(b) Disconnect the A39 brake pedal stroke sensor assembly connector.
(c) Select the Data List on the Techstream.
Chassis > ABS/VSC/TRAC > Data List
|
Tester Display |
Measurement Item |
Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
MT Voltage Value |
MT voltage value |
Min.: 0.00 V, Max.: 20.00 V |
Pump motor off: 0.00 V Pump motor on: 12.00 V |
- |
|
Accumulator Pressure |
Accumulator pressure output value |
Min.: 0.00 MPa, Max.: 24.48 MPa |
15.00 to 21.00 MPa (Pressure stable and pump motor stopped) |
When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator |
Chassis > ABS/VSC/TRAC > Data List
|
Tester Display |
|---|
|
MT Voltage Value |
|
Accumulator Pressure |
(d) Depress the brake pedal several times to operate the pump motor, then wait until it stops.
(e) After the pump motor stops, wait for 30 seconds, then check the drop in the accumulator pressure sensor output value and the state of the pump motor.
|
Result |
Proceed to |
|---|---|
|
The drop in the accumulator pressure sensor output value is less than 2.50 MPa 30 seconds after the pump motor stops, and the pump motor does not operate within 30 seconds after the pump motor stops. |
A |
|
The drop in the accumulator pressure sensor output value is 2.50 MPa or more 30 seconds after the pump motor stops, or the pump motor operates within 30 seconds after the pump motor stops. |
B |
| A |
|
|
|
4. |
READ VALUE USING TECHSTREAM (SERVO PRESSURE) |
(a) Turn the power switch off.
(b) Reconnect the A39 brake pedal stroke sensor assembly connector.
(c) Select the Active Test on the Techstream.
Chassis > ABS/VSC/TRAC > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
ECB Solenoid (SLR) |
Linear solenoid reduction valve (SLR) |
Solenoid ON/OFF |
ECB: Electronically Controlled Brake System |
Chassis > ABS/VSC/TRAC > Data List
|
Tester Display |
Measurement Item |
Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
Servo Pressure |
Pressure value of servo |
Min.: 0.00 MPa, Max.: 24.48 MPa |
Brake pedal released: 0.00 to 2.10 MPa |
Brake pedal is being depressed: Changes in proportion to the depression force of the brake pedal |
Chassis > ABS/VSC/TRAC > Active Test
|
Active Test Display |
|---|
|
ECB Solenoid (SLR) |
|
Data List Display |
|---|
|
Servo Pressure |
(d) Perform the Active Test and operate the linear solenoid (SLR) in the brake actuator (brake booster with master cylinder assembly).
(e) Check that the servo pressure output value does not increase when performing the Active Test.
OK:
The servo pressure output value does not increase when performing the Active Test.
HINT:
If the servo pressure output value increases, an internal brake fluid leak in the brake actuator (brake booster with master cylinder assembly) is suspected.
|
Result |
Proceed to |
|---|---|
|
The servo pressure output value increases. |
A |
|
The servo pressure output value does not increase. |
B |
| A |
|
| B |
|
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER PUMP ASSEMBLY for the brake booster with master cylinder assembly: Click here
for the brake booster pump assembly: Click here
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