Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJ0N
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: STEERING COLUMN: STEERING LOCK SYSTEM: B2788; IG2 Signal Malfunction; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

B2788

IG2 Signal Malfunction

DESCRIPTION

The steering lock ECU determines the on/off status of the engine switch through the IG2 signal circuit.

The steering lock ECU does not lock the steering when it receives the IG2 relay on signal. This prevents the steering from being locked while the vehicle is moving.

The diagnosis information of the steering lock ECU is transmitted to the Techstream via the certification ECU as the steering lock ECU is not connected to the CAN communication system.

DTC Code

Detection Condition

Trouble Area

B2788

The IG2 input to the steering lock ECU does not match the LIN communication input.
  • IG2 fuse
  • Steering lock actuator assembly (steering lock ECU)
  • Power management control ECU
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

When the engine switch is off, the main body ECU may occasionally go into a non-active state called sleep mode. Therefore, before proceeding with the inspection, it is necessary to perform the following steps to wake up the ECU:

With the engine switch off, open the driver door. Then (with the engine switch still off) open and close any door several times at 1.5 second intervals.

NOTICE:

  • If the steering lock actuator assembly (steering lock ECU) is replaced, with the engine switch off and the shift lever in P, open and close the driver side door to record the current lock position into the steering lock ECU. If this is not performed, the engine may not start.
  • When replacing the steering lock ECU, registration must be performed (See page 2016 MY Sienna [12/2015 - 08/2016]; THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM(w/ Smart Key System): REGISTRATION 2017 - 2020 MY Sienna [08/2016 -        ]; THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM(w/ Smart Key System): REGISTRATION ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - BODY GROUND)

(a) Disconnect the D29 steering lock ECU connector.

(b) Turn the engine switch off, make sure that the steering lock is unlocked and move the shift lever to P.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D29-1 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CHECK STEERING LOCK ECU (IG2 VOLTAGE)

(a) Reconnect the D29 steering lock ECU connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

D29-6 (IG2) - D29-1 (GND)

Engine switch on (IG)

11 to 14 V

D29-6 (IG2) - D29-1 (GND)

Engine switch off

Below 1 V

Text in Illustration

*a

Component with harness connected

(Steering Lock ECU)
OK

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

NG

CHECK FOR ALL HARNESSES, CONNECTORS AND COMPONENTS CONNECTED TO IG2 FUSE