LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2021 >> Mirai Limited >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System - Diagnostic Codes (2 Of 4) >> Electronically Controlled Brake System >> DTC C123D-14: IG2 Circuit Short to Ground or Open [11/2020 - ] >> Description

DTC C123D-14: IG2 Circuit Short to Ground or Open [11/2020 - ]: Description

If a malfunction is detected in the power supply circuit, the No. 2 skid control ECU (brake actuator assembly) power source voltage drops, or there is insufficient voltage to operate the main relay, the No. 2 skid control ECU (brake actuator assembly) will store a DTC.

If the auxiliary battery voltage is temporarily low, this DTC may be stored.

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from Priority Note
C123D-14 IG2 Circuit Short to Ground or Open When communication with the EV control ECU is normal or the vehicle speed exceeds 10 km/h, no voltage (below 3.0 V and either PT1 is on or PT2 is on) is applied to the IG2 terminal and the power source voltage (exceeding 9.5 V) is applied to the IG1 terminal continuously for 4 seconds or more.
  • Open or short in IG2 circuit
  • Improperly connected connector, deformation or corrosion of terminals
  • No. 2 skid control ECU (brake actuator assembly)
Brake/EPB A Output ECU: No. 2 skid control ECU (brake actuator assembly)
C123D-14 DTC DETECTION CONDITIONS

  Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4
Diagnosis Condition When communication with the EV control ECU is normal - -
The vehicle speed is exceeds 10 km/h (6 mph) - -
Malfunction Status No voltage (below 3.0 V and either PT1 is on) is applied to the IG2 terminal and the power source voltage (exceeding 9.5 V) is applied to the IG1 terminal continuously -
No voltage (below 3.0 V and either PT2 is on) is applied to the IG2 terminal and the power source voltage (exceeding 9.5 V) is applied to the IG1 terminal continuously - -
Detection Time 4 seconds or more. 4 seconds or more. 4 seconds or more. 4 seconds or more.
Number of Trips 1 trip 1 trip 1 trip 1 trip

HINT: 

DTC will be output when conditions for either of the patterns in the table above are met.