Brake Actuator: Inspection

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

CHECK BRAKE ACTUATOR

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

Fig 1: Identifying Brake Actuator Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Perform the check with the actuator at the lowest temperature possible.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
20 (SMC1) -19 (BS1)	Always	15.3 to 25.0 Ω
6 (SMC2) - 7 (BS2)	Always	15.3 to 25.0 Ω
8 (FRA+) - 5 (FRA-)	Always	3.6 to 6.0 Ω
22 (FRR+) - 21 (FRR-)
13 (FLA+) -14 (FLA-)
27 (FLR+) - 28 (FLR-)
12 (RRA+) -11 (RRA-)
10 (RLA+) - 9 (RLA-)
26 (RRR+) - 25 (RRR-)	Always	4.4 to 7.0 Ω
24 (RLR+) - 23 (RLR-)	Always	4.4 to 7.0 Ω

If the result is not as specified, replace the brake actuator.

CHECK BRAKE ACCUMULATOR PUMP

Fig 2: Identifying Brake Accumulator Pump Connector Terminals

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
A2 (BM1) - A4 (GND1)	Always	10 Ω or less
B2 (BM2) - A4 (GND1)	Always	10 Ω or less
A2 (BM1) - B2 (BM2)	Always	Below 1 Ω
A4 (GND1) - B1 (GND2)	Always	Below 1 Ω
A2 (BM1) - A1 (MTT)	Always	950 to 1050 Ω
B2 (BM2) - A1 (MTT)	Always	950 to 1050 Ω

If the result is not as specified, replace the brake accumulator pump.