DTC B2788: IG2 Signal Malfunction [10/2018 - 07/2022]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (POWER SOURCE)
- Disconnect the F45 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
- Measure the voltage according to the value(s) in the table below.
*a Front view of wire harness connector
(to Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))Standard Voltage
Tester Connection Switch Condition Specified Condition F45-6 (IG2) - Body ground Power switch on (IG) 11 to 14 V F45-6 (IG2) - Body ground Power switch off Below 1 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (GROUND)
- Measure the resistance according to the value(s) in the table below.
*a Front view of wire harness connector
(to Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))Standard Resistance
Tester Connection Condition Specified Condition F45-1 (GND) - Body ground Always Below 1 Ω Result
Result Proceed to OK (for Manual Tilt and Manual Telescopic Steering Column) A OK (for Power Tilt and Power Telescopic Steering Column) B NG C
Result:
A
REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to DISASSEMBLY [10/2018 - 07/2022]
Result:
B
REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to DISASSEMBLY [10/2018 - 07/2022]
Result:
C
REPAIR OR REPLACE HARNESS OR CONNECTOR
- Measure the resistance according to the value(s) in the table below.