| DTC Code | DTC Name |
|---|---|
| C1252 | Brake Booster Pump Motor on Time Abnormally Long |
| C1253 | Pump Motor Relay |
DESCRIPTION
The skid control ECU assembly 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 ABS motor relay.
The skid control ECU assembly usually drives the ABS motor relay 1 for electronically controlled brake system control, and the ABS motor relay 2 for ABS control. If either of them is malfunctioning, the other will substitute.
| DTC No. | Detection Item | INF Code | DTC Detection Condition | Trouble Area | Note |
|---|---|---|---|---|---|
| C1252 | Brake Booster Pump Motor on Time Abnormally Long | 130 | ABS motor relay is on for at least 3 minutes. |
|
- |
| C1253 | Pump Motor Relay | 134 138 140 |
|
|
- |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
When replacing the skid control ECU assembly or brake actuator assembly, perform initialization and calibration of the linear solenoid valve.
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
PERFORM ACTIVE TEST USING GTS (ABS MOTOR RELAY)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Select the Active Test on the GTS.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| ECB Motor Relay | ABS motor relay 1 | Relay ON/OFF |
|
| ECB Motor Relay2 | ABS motor relay 2 | Relay ON/OFF |
|
| Tester Display |
|---|
| ECB Motor Relay |
ECB: Electronically Controlled Brake System
| Tester Display |
|---|
| ECB Motor Relay2 |
ECB: Electronically Controlled Brake System
Check the operation sound of the ABS motor relay and motor when operating it using the GTS.
| OK |
|---|
| The operation sound of the ABS motor relay and motor should be heard. |
| Result | |||
|---|---|---|---|
|
| NG |
|
INSPECT ABS MOTOR RELAY Click here |
| OK |
|
INSPECT BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY
| *a | Component without harness connected (Brake Booster with Accumulator Pump Assembly) |
Make sure that there is no looseness at the locking part and the connecting part of the connectors.
Disconnect the A46 and A47 brake booster with accumulator pump assembly connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY)
Make sure that there is no looseness at the locking part and the connecting part of the connector.
Disconnect the A10 skid control ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
READ VALUE USING GTS (ACCUMULATOR PRESSURE SENSOR)
Reconnect the A10 skid control ECU assembly connector.
Reconnect the A46 and A47 brake booster with accumulator pump assembly connectors.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Select the Data List on the GTS.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Accumulator Sensor | Accumulator pressure sensor | Min.: 0.00 V, Max.: 5.00 V | Specified value: 2.60 to 3.80 V | When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator |
| Tester Display |
|---|
| Accumulator Sensor |
Depress the brake pedal 4 or 5 times and operate the pump motor.
Wait for 30 seconds without depressing the brake pedal.
Check that the accumulator pressure sensor output value change is within the specified range.
| OK |
|---|
| Accumulator pressure sensor output value change is less than 0.20 V. |
Tech Tips
This inspection is performed to determine if a long-term power malfunction occurred when low pressure is detected due to a defective sensor, an internal leak in the brake actuator assembly, or deterioration of the accumulator.
External brake fluid leaks are suspected if the fluid level drops inside the brake master cylinder reservoir assembly.
| Result | |||
|---|---|---|---|
|
| NG |
|
PERFORM ACTIVE TEST USING GTS (SOLENOID VALVE) Click here |
| OK |
|
RECONFIRM DTC
Turn the engine switch off.
Clear the DTCs.
Turn the engine switch off.
Turn the engine switch on (IG).
Check if the same DTC is output.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
USE SIMULATION METHOD TO CHECK Click here |
| B |
|
REPLACE SKID CONTROL ECU ASSEMBLY Click here |
PERFORM ACTIVE TEST USING GTS (SOLENOID VALVE)
With the brake pedal released, set "ECB Solenoid (SMC1)" to "ON" and check the output voltage of "FR W/C Sensor".
ECB: Electronically Controlled Brake System
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| ECB Solenoid (SMC1) | Master cut solenoid (SMC1) | Solenoid ON/OFF | ECB: Electronically Controlled Brake System |
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| FR W/C Sensor | Front wheel cylinder pressure sensor RH | Min.: 0.00 V, Max.: 5.00 V | Brake pedal released: 0.30 to 0.70 V | Reading increases when brake pedal is depressed |
| Active Test Display |
|---|
| ECB Solenoid (SMC1) |
| Data List Display |
|---|
| FR W/C Sensor |
ECB: Electronically Controlled Brake System
| OK |
|---|
| The output value of the wheel cylinder pressure sensor does not increase. |
Tech Tips
If output value increases, there may be brake fluid leaks in the brake actuator assembly.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (SOLENOID VALVE)
With the brake pedal released, set "ECB Solenoid (SMC2)" to "ON" and check the output voltage of "FL W/C Sensor".
ECB: Electronically Controlled Brake System
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| ECB Solenoid (SMC2) | Master cut solenoid (SMC2) | Solenoid ON/OFF | ECB: Electronically Controlled Brake System |
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| FL W/C Sensor | Front wheel cylinder pressure sensor LH | Min.: 0.00 V, Max.: 5.00 V | Brake pedal released: 0.30 to 0.70 V | Reading increases when brake pedal is depressed |
| Active Test Display |
|---|
| ECB Solenoid (SMC2) |
| Data List Display |
|---|
| FL W/C Sensor |
ECB: Electronically Controlled Brake System
| OK |
|---|
| The output value of the wheel cylinder pressure sensor does not increase. |
Tech Tips
If output value increases, there may be brake fluid leaks in the brake actuator assembly.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (SOLENOID VALVE)
With the brake pedal released, set the current of "ECB Solenoid (SLRRR)" to 1.2 A and check the output voltage of "RR W/C Sensor".
ECB: Electronically Controlled Brake System
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| ECB Solenoid (SLRRR) | Linear solenoid (RRR) valve | Solenoid ON/OFF | ECB: Electronically Controlled Brake System |
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| RR W/C Sensor | Rear wheel cylinder pressure sensor RH | Min.: 0.00 V, Max.: 5.00 V | Brake pedal released: 0.30 to 0.70 V | Reading increases when brake pedal is depressed |
| Active Test Display |
|---|
| ECB Solenoid (SLRRR) |
| Data List Display |
|---|
| RR W/C Sensor |
ECB: Electronically Controlled Brake System
| OK |
|---|
| The output value of the wheel cylinder pressure sensor does not increase. |
Tech Tips
If output value increases, there may be brake fluid leaks in the brake actuator assembly.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (SOLENOID VALVE)
With the brake pedal released, set the current of "ECB Solenoid (SLRRL)" to 1.2 A and check the output voltage of "RL W/C Sensor".
ECB: Electronically Controlled Brake System
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| ECB Solenoid (SLRRL) | Linear solenoid (RLR) valve | Solenoid ON/OFF | ECB: Electronically Controlled Brake System |
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| RL W/C Sensor | Rear wheel cylinder pressure sensor LH | Min.: 0.00 V, Max.: 5.00 V | Brake pedal released: 0.30 to 0.70 V | Reading increases when brake pedal is depressed |
| Active Test Display |
|---|
| ECB Solenoid (SLRRL) |
| Data List Display |
|---|
| RL W/C Sensor |
ECB: Electronically Controlled Brake System
| OK |
|---|
| The output value of the wheel cylinder pressure sensor does not increase. |
Tech Tips
If output value increases, there may be brake fluid leaks in the brake actuator assembly.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY Click here |
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
INSPECT ABS MOTOR RELAY
| *1 | ABS Motor Relay (ABS MTR NO. 1 or ABS MTR NO. 2 relay) |
Remove the ABS motor relay (ABS MTR NO. 1 and ABS MTR NO. 2 relays).
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE ABS MOTOR RELAY |
| OK |
|
INSPECT NO. 1 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK (POWER SOURCE TERMINAL)
| *1 | No. 1 Engine Room Relay Block and Junction Block |
| *2 | ABS MTR NO. 1 Relay |
| *3 | ABS MTR NO. 2 Relay |
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) |
| OK |
|
CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK)
Make sure that there is no looseness at the locking part and the connecting part of the connector.
Disconnect the A46 and A47 brake booster with accumulator pump assembly connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK)
Make sure that there is no looseness at the locking part and the connecting part of the connectors.
Disconnect the A13 and A10 skid control ECU assembly connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE SKID CONTROL ECU ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |