BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): C1202; Master Reservoir Level Malfunction; 2019 - 2021 MY RAV4 RAV4 HV [02/2019

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001HG8E
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): C1202; Master Reservoir Level Malfunction; 2019 - 2021 MY RAV4 RAV4 HV [02/2019 - 12/2021]

DTC

C1202

Master Reservoir Level Malfunction

DESCRIPTION

When a fluid level drop in the brake master cylinder reservoir assembly is detected, a signal is sent to the skid control ECU (brake booster with master cylinder assembly).

If a DTC for the fluid level drop is stored, the warning will be canceled and the DTC will be cleared when the fluid level returns to normal.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

Note

C1202

Master Reservoir Level Malfunction

371

INF Code: 371
- An open is detected in the switch signal circuit for 2 seconds or more.
INF Code: -
- The reservoir level remains low.

INF Code: 371
- Brake fluid level warning switch (Brake master cylinder reservoir assembly) internal open circuit
- Open in wire harness
- Skid control ECU (Brake booster with master cylinder assembly)
INF Code: -
- Low brake fluid level
- Brake fluid leaks
- Brake fluid level warning switch (Brake master cylinder reservoir assembly) internal short circuit
- Short in wire harness
- Brake disc rotor excessive wear
- 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), perform initialization and calibration of the linear solenoid valve.

Click here

HINT:

Before releasing the parking brake, chock the wheels for safety.

PROCEDURE

1.	CHECK BRAKE FLUID LEVEL

(a) Check that the brake fluid level is sufficient.

OK:

Brake fluid level is sufficient.

HINT:

If the fluid level is low, check for fluid leaks, and repair as necessary.

(1) Check for brake fluid leaks (connection between the brake booster pump assembly, brake master cylinder reservoir assembly and brake booster with master cylinder assembly, and the brake booster with master cylinder assembly and wheel cylinders).

HINT:

If no leaks exist, add and adjust fluid using the Techstream.

Click here

(2) Check that the DTC is not output again.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

(b) Check that there are no leaks from the connections between the brake booster pump assembly and brake booster with master cylinder assembly.

HINT:

As a visual check is very difficult, perform the check with the following procedure.

(1) Bleed the air from the brake system.

Click here

(2) Connect the Techstream to the DLC3.

(3) Turn the ignition switch to ON.

(4) 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

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

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

(7) 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.

CHECK AND REPAIR BRAKE FLUID LEAKS OR ADD FLUID

2.	INSPECT BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY

(a) Turn the ignition switch off.

*a	Component without harness connected (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Assembly))

(b) Remove the reservoir filler cap.

(d) Disconnect the A4 brake fluid level warning switch (brake master cylinder reservoir assembly) connector.

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

HINT:

A float is located inside the reservoir. Its position changes according to the level of brake fluid.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
1 (+) - 2 (E)	Brake fluid level warning switch off (float up)	1.84 to 2.16 kΩ
1 (+) - 2 (E)	Brake fluid level warning switch on (float down)	Below 1 Ω

REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY

3.	CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY)

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

(b) Disconnect the A42 skid control ECU (brake booster with master cylinder assembly) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-36 (LBL) - A4-1 (+)	Always	Below 1 Ω
A42-36 (LBL) or A4-1 (+) - Body ground	Always	10 kΩ or higher
A4-2 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SWITCH INPUT)

(a) Reconnect the A42 skid control ECU (brake booster with master cylinder assembly) connector.

*a	Front view of wire harness connector (to Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Assembly))

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A4-1 (+) - Body ground	Ignition switch ON	11 to 14 V

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

5.	CHECK BRAKE DISC

(a) Turn the ignition switch off.

(b) Reconnect the A4 brake fluid level warning switch (brake master cylinder reservoir assembly) connector.

(d) Perform a road test according to Freeze Frame Data or customer problem analysis. While driving, check for abnormal brake pedal vibration caused by brake discs that are worn or have excess runout.

OK:

Brake pedal does not vibrate during braking.

HINT:

An unevenly worn disc may vibrate the caliper pistons and cause fluctuations in brake line pressure, triggering a malfunction detection condition.
The brake pedal does not kick back due to caliper piston vibration during electronically controlled brake system control.
If the brake pedal stroke sensor assembly connector is disconnected, the fail-safe function will prohibit electronically controlled brake system control.
The Active Test does not prohibit electronically controlled brake system control when the vehicle is being driven, so disconnect the brake pedal stroke sensor assembly connector before continuing with inspection.
Uneven disc wear can be checked by measuring the disc thickness variation.
for Front Brake: Click here

for Rear Brake: Click here

REPLACE BRAKE DISC

6.	RECONFIRM DTC

(a) Reconnect the A41 brake pedal stroke sensor assembly connector.

(b) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

(d) Perform a road test.

(e) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTC C1202 is not output.	A
DTC C1202 is output.	B

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step.

Click here

USE SIMULATION METHOD TO CHECK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY