Steering

Power Source Control ECU Malfunction (B2782)

~4min read
DESCRIPTION

The steering lock ECU activates the steering lock motor with the power from the power management control ECU through the IGE circuit. This prevents the steering from being locked while the vehicle is moving.

If NG (PAST) is displayed for Power Supply Open in the Data List, perform troubleshooting according to the procedures below.

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

DTC Code

Detection Condition

Trouble Area

B2782

An IGE power supply circuit malfunction.

  • 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:

  • When disconnecting the cable from the negative (-) battery terminal, some systems need to be initialized after the cable is reconnected (See page ).

  • 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 ).
PROCEDURE
  1. INSPECT STEERING LOCK ECU

(a) Disconnect the F68 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

F68-1 (GND) - Body ground

Always

Below 1 Ω

Text in Illustration

*a

Front view of wire harness connector

(to Steering Lock ECU)

(d) Reconnect the F68 steering lock ECU connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

F68-3 (IGE) - F68-1 (GND)

Driver side door opened

Below 1 V (Steering lock motor operating)

F68-3 (IGE) - F68-1 (GND)

Driver side door opened

11 to 14 V (Steering lock motor not operating)

HINT:

When the steering lock is locked and the engine is switch is turned on (IG), the steering lock motor activates to release the steering lock. The motor operates for 2 to 15 seconds.

Text in Illustration

*a

Component with harness connected

(Steering Lock ECU)


NG

GO TO STEP 4

OK
  1. CLEAR DTC

(a) Clear the DTCs (See page ).


(b) Disconnect and reconnect the cable to the negative (-) battery terminal to clear the malfunction history of Power Supply Open.

NEXT
  1. READ VALUE USING TECHSTREAM (POWER SUPPLY OPEN)

(a) Check for DTCs (See page ).


(b) Use the Data List to check if the steering lock control is functioning properly.

Smart Key

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Power Supply Open

Open in ECU record/NG (PAST) or OK

NG (PAST): Open in ECU

OK: No malfunction

-

Result

Result

Proceed to

  • B2782 is not output
  • "OK" is displayed on the Techstream.

A

  • B2782 is output
  • "NG (PAST)" is displayed on the Techstream.

B


A

USE SIMULATION METHOD TO CHECK


B

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

  1. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the F80 power management control ECU connector.

(b) Disconnect the F68 steering lock ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F68-3 (IGE) - F80-8 (SLR+)

Always

Below 1 Ω

F68-3 (IGE) or F80-8 (SLR+) - Body ground

Always

10 kΩ or higher


OK

REPLACE POWER MANAGEMENT CONTROL ECU


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Test yourself

A quick Toyota 4Runner quiz: every answer comes with an explanation and a link to the manual page.