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Home >> Lexus >> 2019 >> ES 350 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 108 (Electronically Controlled Brake System (Hybrid) - Diagnostic Codes (2 Of 5)) >> ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model) >> DTC C1311: Open Circuit in Main Relay 1; DTC C1312: Short Circuit in Main Relay 1 [06/2018 - ] >> Monitor Description

Monitor Description

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The skid control ECU (brake booster with master cylinder assembly) monitors the voltage at BS terminal.

When the main relay is instructed to be on and the voltage at BS terminal is within the range of an open circuit malfunction (voltage is practically equal to that when off), or when the main relay is instructed to be off and the voltage of the BS terminal is within the range of a short circuit malfunction (voltage is practically equal to that when on), an open circuit or short circuit is judged respectively and the MIL is illuminated and stores a DTC.