DESCRIPTION
The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).
DTC No. |
DTC Detecting Condition |
Trouble Areas |
---|---|---|
C1252 |
Motor operates for 5 minutes or more. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
HINT:
When C1253, C1254 or C1256 is output together with C1252, inspect and repair the trouble areas indicated by C1253, C1254 or C1256 first.
PROCEDURE
1. |
CHECK HYDRAULIC BRAKE BOOSTER PUMP MOTOR OPERATION |
(a) Turn the ignition switch to OFF.
(b) Depress the brake pedal more than 20 times.
(c) Turn the ignition switch to the ON position.
(d) Check how the hydraulic brake booster pump motor operates.
Result |
Proceed to |
---|---|
Pump motor does not operate |
A |
Pump motor operates continuously (Does not stop) |
B |
Pump motor operates intermittently |
C |
Pump motor operates, then stops |
D |
B |
REPLACE HYDRAULIC BRAKE BOOSTER |
C |
GO TO STEP 4 |
D |
GO TO STEP 5 |
|
2. |
CHECK BRAKE PUMP MOTOR WIRE HARNESS CONNECTION (MT+ / MT-) |
(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster (See page ).
(b) Check the tightening torque of 2 screws which fasten the wire harness connecting hydraulic brake booster and brake booster pump (See page ).
Torque:
2.9 N·m {30 kgf·cm, 26 in·lbf}
NG |
RETIGHTEN SCREWS |
|
3. |
CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS (MT+/MT-) |
(a) Using a screwdriver, remove the 2 screws and pull the wire harness from the hydraulic brake booster assembly. |
|
(b) Measure the resistance between the red wire (MT+) and black wire (MT-).
Resistance:
2 Ω
NG |
REPLACE HYDRAULIC BRAKE BOOSTER |
|
4. |
READ VALUE USING DATA LIST (ACCUMULATOR SENSOR) |
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn Techstream ON.
(d) Select the Data List mode on the Techstream.
ABS/VSC/TRAC
Tester Display |
Measurement Item / Range |
Normal Condition |
Diagnostic Note |
---|---|---|---|
Accumulator Sensor |
Accumulator pressure sensor reading / min.: 0 V, max.: 5 V |
3.58 to 5 V |
If value constant regardless of pump operation, accumulator pressure sensor malfunction suspected. |
(e) Check that the accumulator pressure sensor output is normal.
Result |
Proceed to |
---|---|
Output value varies within "Normal Condition" range |
A |
Output value does not reach "Normal Condition" range |
B |
Output value constant regardless of pump motor operation |
C |
B |
REPLACE MASTER CYLINDER SOLENOID |
C |
REPLACE HYDRAULIC BRAKE BOOSTER |
|
5. |
RECONFIRM DTC |
(a) Clear the DTCs (See page ).
(b) Turn the ignition switch to OFF.
(c) Turn the ignition switch to the ON position.
(d) Wait for more than 5 minutes.
(e) Check if the same DTCs are recorded.
Result |
Proceed to |
---|---|
DTC output |
A |
DTC not output |
B |
A |
REPLACE MASTER CYLINDER SOLENOID |
B |
REPLACE HYDRAULIC BRAKE BOOSTER |
Installation
INSTALLATION
CAUTION / NOTICE / HINT
NOTICE:
Always use a new grommet and valve core when installing the tire pressure
warning valve and transmitter.
Check that the washer and nut are not damaged, and replace them if necessary.
If installing a new tire pressure warning valv ...
Terminals Of Ecu
TERMINALS OF ECU
1. CHECK DRIVER SIDE JUNCTION BLOCK AND MAIN BODY ECU (MULTIPLEX NETWORK BODY
ECU)
(a) Disconnect the MB main body ECU (multiplex network body ECU) connectors.
(b) Measure the voltage and resistance according to the value(s) in the table
below.
HINT:
Measure the values on ...
Theft deterrent system
Engine immobilizer system
The vehicle’s keys have built-in transponder chips that prevent the engine from
starting if the key has not been previously registered in the vehicle’s on-board
computer.
Never leave the keys inside the vehicle when you leave the vehicle.
The indicator light fl ...