Pinout Values and Diagnostic Parameters

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: TERMINALS OF ECU

1. CHECK AUXILIARY BATTERY VOLTAGE

(a) Check the auxiliary battery voltage.

Standard Voltage:

11 to 14 V

2. SKID CONTROL ECU INSPECTION

(a) Measure the voltage between each terminal or between each terminal and body ground.

(b) Connect the Techstream to the DLC3 and check the communication condition of the skid control ECU.

(c) Using an oscilloscope, check the pulse generated between each terminal or between each terminal and body ground.

NOTICE:
* Inspections should be performed from the back of the connector with the connector connected to the skid control ECU.
* The voltage between the terminals of the brake actuator assembly may become 0 V due to the fail-safe function when the brake warning light / yellow (minor malfunction) comes on (malfunctioning).





Text in Illustration





HINT
Inspect the ECU from the wire harness side while the connector is connected.

















(d) Using an oscilloscope, check waveform 1.





Waveform 1 (Reference)





HINT
The normal waveform is output only when +BI voltage is normal (11 to 14 V).

(e) Using an oscilloscope, check waveform 2.





Waveform 2 (Reference)





HINT
The normal waveform is output only when +BI voltage is normal (11 to 14 V).

(f) Using an oscilloscope, check waveform 3.





Waveform 3 (Reference)





HINT
As the vehicle speed (tire rotation speed) becomes faster, the cycle becomes shorter.

(g) Using an oscilloscope, check waveform 4.





Waveform 4 (Reference)





HINT
As the vehicle speed (tire rotation speed) becomes faster, the cycle becomes shorter.

(h) Using an oscilloscope, check waveform 5.





Waveform 5 (Reference)





(i) Using an oscilloscope, check waveform 6.





Waveform 6 (Reference)