Dtc B2788 Ig2 Signal Malfunction

Steering. Lexus Gs430, Gs300. Uzs190 Grs190
Steering Column. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT IG2 RELAY

CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BODY GROUND)

CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BATTERY)

DTC B2788 IG2 Signal Malfunction


DESCRIPTION

The steering lock ECU receives IG2 relay signals. Receiving the signals, the steering lock ECU determines that the vehicle is moving. The steering lock ECU does not lock the steering when it receives an IG2 relay ON signal (to prevent the steering from being locked while the vehicle is moving).

DTC No.
DTC Detecting Condition
Trouble Area
B2788
  1. Different information is obtained from IG2 signals received directly from the IG2 circuit, and from IG2 signals sent via LIN communication for a period of 1 second.
  1. IG2 relay
  2. Wire harness
  3. Power source control ECU assembly
  4. Steering lock actuator assembly (Steering lock ECU)

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Steering Column.Steering System. Dtc B2788 Ig2 Signal Malfunction


INSPECTION PROCEDURE

1.INSPECT IG2 RELAY


    Lexus Gs430, Gs300. Uzs190 Grs190.Steering Column.Steering System. Dtc B2788 Ig2 Signal Malfunction

  1. Remove the IG2 relay from the engine room J/B and R/B No.2.

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

    Resistance:
    Tester Connection
    		Specified Condition
    3 - 5
    		10 kΩ or higher
    3 - 5
    		Below 1 Ω
    (when battery voltage is applied to terminals 1 and 2)


NG
REPLACE IG2 RELAY
OK


2.CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BODY GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Steering Column.Steering System. Dtc B2788 Ig2 Signal Malfunction

  1. Disconnect the L28 connector from the steering lock actuator assembly.

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

    Resistance:
    Tester connection
    (Symbols)
    		Condition
    		Specified condition
    L28-1 (GND) - Body ground
    		Always
    		Below 1 Ω
    L28-2 (SGND) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BATTERY)


    Lexus Gs430, Gs300. Uzs190 Grs190.Steering Column.Steering System. Dtc B2788 Ig2 Signal Malfunction

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

    Voltage:
    Tester connection
    (Symbols)
    		Condition
    		Specified condition
    L28-6 (IG2) - L28-1 (GND)
    		Engine switch on (IG)
    		10 to 14 V
    L28-6 (IG2) - L28-2 (SGND)
    		Engine switch on (IG)
    		10 to 14 V

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

    Resistance:
    Tester connection
    (Symbols)
    		Condition
    		Specified condition
    *L28-6 (IG2) - L28-7 (B)
    		Engine switch off
    		10 kΩ higher
    *: This measurement is performed with the engine switch off to check for a battery voltage short in the IG2 circuit.


OK
REPLACE STEERING LOCK ACTUATOR ASSEMBLY
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING LOCK ACTUATOR ASSEMBLY - BATTERY)