BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): C1252,C1253; Brake Booster Pump Motor on Time Abnormally Long; 2019 - 2021 MY RAV4 RAV4 HV [02/2019

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001HG8T
Model Year Start: 2019	Model: RAV4	Prod Date Range: [02/2019 - 12/2021]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): C1252,C1253; Brake Booster Pump Motor on Time Abnormally Long; 2019 - 2021 MY RAV4 RAV4 HV [02/2019 - 12/2021]

DTC

C1252

Brake Booster Pump Motor on Time Abnormally Long

DTC

C1253

Pump Motor Relay

DESCRIPTION

The skid control ECU (brake booster with master cylinder 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 motor relay.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

Note

C1252

Brake Booster Pump Motor on Time Abnormally Long

311

The pump motor is operating continuously for 178 seconds or more. (When the relay is malfunctioning for 98 seconds or more.)

Short in motor circuit or motor monitor circuit
Motor relay stuck
Accumulator pressure sensor malfunction in brake actuator (Brake booster with master cylinder assembly)
Skid control ECU (Brake booster with master cylinder assembly)

C1253

Pump Motor Relay

321

322

323

324

325

326

327

328

329

INF Code: 321
- With IG1 terminal voltage 9.5 V higher than, the motor drive monitor remains off for 0.2 seconds or more after a motor drive on request.
INF Code: 322
- The motor drive monitor remains on for 2 seconds or more after a motor drive off request.
INF Code: 323
- A skid control ECU (brake booster with master cylinder assembly) internal motor drive logical inconsistency continues for 2 seconds or more.
INF Code: 324
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relays 1 and 2.
INF Code: 325
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relays 1 and 3.
INF Code: 326
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relays 2 and 3.
INF Code: 327
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relay 1.
INF Code: 328
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relay 2.
INF Code: 329
- An open circuit is detected in the skid control ECU (brake booster with master cylinder assembly) internal motor relay 3.

INF Code: 321, 324, 325, 326, 327, 328, 329
- Open in motor circuit or motor monitor circuit
- Skid control ECU (Brake booster with master cylinder assembly)
INF Code: 322
- Short in motor circuit or motor monitor circuit
- Skid control ECU (Brake booster with master cylinder assembly)
INF Code: 323
- Skid control ECU (Brake booster with master cylinder assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake booster with master cylinder assembly) or brake actuator (brake booster with master cylinder assembly), perform initialization and calibration of the linear solenoid valve.
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

Click here

Chassis > ABS/VSC/TRAC > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
ECB Motor Relay	ABS motor relay	Relay ON/OFF	ECB: Electronically Controlled Brake System

Chassis > ABS/VSC/TRAC > Active Test

Tester Display
ECB Motor Relay

(d) Select the Data List on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

ECB Motor Relay

ABS motor relay

ON or OFF

ON: Relay on

OFF: Relay off

ECB: Electronically Controlled Brake System

Chassis > ABS/VSC/TRAC > Data List

Tester Display
ECB Motor Relay

(e) Check the operating condition of the ABS motor relay when operating it with the Techstream.

Result	Proceed to
ABS motor relay in the Data List turns ON/OFF using the Active Test.	A
ABS motor relay in the Data List does not change using the Active Test.	B

GO TO STEP 7

2.	INSPECT BRAKE BOOSTER PUMP ASSEMBLY

(a) Turn the ignition switch off.

*a	Component without harness connected (Brake Booster Pump Assembly)

(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (BM1) - 4 (GND1)	Always	Below 10 Ω
1 (BM2) - 3 (GND2)	Always	Below 10 Ω
2 (BM1) - 1 (BM2)	Always	Below 1 Ω
4 (GND1) - 3 (GND2)	Always	Below 1 Ω

REPLACE BRAKE BOOSTER PUMP ASSEMBLY

3.	CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A49-4 (GND1) - Body ground	Always	Below 1 Ω
A49-3 (GND2) - Body ground	Always	Below 1 Ω

*a	Front view of wire harness connector (to Brake Booster Pump Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

4.	READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)

(a) Reconnect the A49 brake booster pump assembly connectors.

(b) Connect the Techstream to the DLC3.

(d) Select the Data List on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Accumulator Sensor	Accumulator pressure sensor	Min.: 0.00 V, Max.: 5.00 V	Specified value: 2.90 to 4.20 V	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
Accumulator Sensor

(e) Depress the brake pedal 4 or 5 times to operate the pump motor.

(f) Wait for 30 seconds without depressing the brake pedal.

(g) Check that the accumulator pressure sensor output value change is within the specified range.

OK:

Accumulator pressure sensor output value change is less than 0.55 V.

GO TO STEP 6

5.	RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Turn the ignition switch off.

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1252 and C1253 are not output.	A
DTCs C1252 and/or C1253 are output.	B

USE SIMULATION METHOD TO CHECK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

6.	PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE)

(a) Select the Active Test on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
ECB Solenoid (SMC/SRC/SCC)	Switching solenoid valve (SMC/SRC/SCC)	Solenoid ON/OFF	Operation sound of solenoid (clicking sound) can be heard ECB: Electronically Controlled Brake System

Chassis > ABS/VSC/TRAC > Active Test

Tester Display
ECB Solenoid (SMC/SRC/SCC)

HINT:

The Active Test can be performed when the following conditions are met.

ABS main relay is on.
Shift lever is in P.
Parking brake is applied.
Vehicle speed is 0 km/h (0 mph).

(b) Perform the Active Test of the solenoid using the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Wheel Cylinder Pressure Sensor	Wheel cylinder pressure sensor	Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.10 to 0.90 V	Reading increases when brake pedal is depressed

Chassis > ABS/VSC/TRAC > Data List

Tester Display
Wheel Cylinder Pressure Sensor

(d) Check that the output value of the wheel cylinder pressure sensor does not increase.

OK:

The output value of the wheel cylinder pressure sensor does not increase.

HINT:

If the output value increases, there may be brake fluid leaks in the brake actuator.

REPLACE BRAKE BOOSTER PUMP ASSEMBLY

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

7.	CHECK HARNESS AND CONNECTOR (MRI TERMINAL)

(a) Turn the ignition switch off.

*a	Front view of wire harness connector (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A42-1 (MRI1) - Body ground	Always	11 to 14 V
A42-2 (MRI2) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (MRI CIRCUIT)

8.	CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE BOOSTER PUMP ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

(b) Disconnect the A49 brake booster pump assembly connectors.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-29 (MRO1) - A49-2 (BM1)	Always	Below 1 Ω
A42-29 (MRO1) or A49-2 (BM1) - Body ground	Always	10 kΩ or higher
A42-30 (MRO2) - A49-1 (BM2)	Always	Below 1 Ω
A42-30 (MRO2) or A49-1 (BM2) - Body ground	Always	10 kΩ or higher

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR