Up to 08/2009
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1252/52,C1253/53: Brake Booster Pump Motor on Time Abnormally Long
C1253/53 - Pump Motor Relay Malfunction
DESCRIPTION
The skid control ECU detects decreases in the accumulator pressure according to the data from the accumulator pressure sensor, and then starts and stops the pump motor by operating the motor relay.
The skid control ECU usually drives the motor relay 1 for electronically controlled brake system control, and the motor relay 2 for ABS control. If either of them is malfunctioning, the other will substitute.
*: Electronically Controlled Brake System
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the skid control ECU or brake actuator assembly, perform initialization and calibration of the linear solenoid valve Initialization.
PROCEDURE
1. PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the Active Test on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(d) *: Electronically Controlled Brake System
(e) Check the operation sound of the ABS motor relay and motor when operating it using the Techstream.
OK:
The operation sound of the ABS motor relay and motor should be heard.
NG -- INSPECT ECB* NO. 1, 2 FUSE
OK -- Continue to next step.
2. INSPECT BRAKE BOOSTER PUMP
(a) Turn the power switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the brake booster pump connectors.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPLACE BRAKE BOOSTER PUMP Removal
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE BOOSTER PUMP)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.
(b) Disconnect the skid control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)
(a) Reconnect the skid control ECU connector and the brake booster pump connectors.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(e) Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on the Techstream with the motor stopped (not braking).
OK:
Accumulator pressure sensor output voltage does not drop.
NG -- PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE)
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch on (IG).
(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:
B -- REPLACE SKID CONTROL ECU Removal
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
6. INSPECT ECB* NO. 1, 2 FUSE
(a) Turn the power switch off.
(b) Remove the fusible link block from the engine room relay block.
(c) Check if the fusible link is melted.
OK:
The fusible link is not melted.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(e) *: Electronically Controlled Brake System
NG -- REPLACE FUSIBLE LINK BLOCK (ECB* NO. 1, 2 FUSE)
OK -- Continue to next step.
7. INSPECT ABS MOTOR RELAY (ECB* MTR1, 2)
(a) Install the fusible link block to the engine room relay block.
(b) Remove the ECB* MTR1 relay and the ECB* MTR2 relay.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(d) *: Electronically Controlled Brake System
NG -- REPLACE ABS MOTOR RELAY (ECB* MTR1, 2)
OK -- Continue to next step.
8. INSPECT ENGINE ROOM NO. 2 RELAY BLOCK (POWER SOURCE TERMINAL)
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
(b) *: Electronically Controlled Brake System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER PUMP - ENGINE ROOM NO. 2 RELAY BLOCK)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the brake booster pump connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(d) *: Electronically Controlled Brake System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 2 RELAY BLOCK)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the skid control ECU connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(d) *: Electronically Controlled Brake System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE SKID CONTROL ECU Removal
11. PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE)
(a) Select the Active Test on the Techstream Data List / Active Test.
HINT
The Active Test can be performed when the following conditions are met.
* ABS main relays 1 and 2 are on.
* Shift lever is in P.
* Parking brake is applied.
* Vehicle speed is 0 km/h (0 mph).
ABS/VSC/TRAC
(b) *: Electronically Controlled Brake System
(c) Perform the Active Test of the solenoid using the Techstream.
(d) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(e) Check that the output value of each wheel cylinder does not increase.
OK:
The output value of each wheel cylinder does not increase.
HINT
If any output value increases, there may be a brake fluid leak in the brake actuator.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- REPLACE BRAKE BOOSTER PUMP Removal