Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR DTCS
1. Delete the DTCs (See DTC CHECK / CLEAR ).
2. After all DTCs are cleared, check if the trouble occurs again 5 seconds after the engine switch is turned on (IG).
3. Check for DTCs again.
  OK: DTC B2785 (Communication malfunction between ECUs connected by LIN), DTC B2287 (LIN communication master malfunction) and DTC B2781 (Open/short in steering lock ECU) are not output.
  
  HINT:
  - If DTC B2785 is output, (See DTC B2785 COMMUNICATION MALFUNCTION BETWEEN ECUS CONNECTED BY LIN ).
  - If DTC B2287 is output, (See DTC B2287 LIN Communication Master Malfunction ).
  - If DTC B2281 is output, (See DTC B2781 OPEN / SHORT IN STEERING LOCK ECU ).
NG: GO TO DTC CHART

OK: Go to Next Step

CHECK WIRE HARNESS (MAIN BODY ECU - STEERING LOCK ECU)

Disconnect the E61 and E78 ECU connectors.

Fig 1: Disconnecting E78 Steering Lock ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
E61-18 (SLP) - E78-4 (SLP1)	Always	Below 1 Ω
E61-18 (SLP) or E78-4 (SLP1) - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

CHECK MAIN BODY ECU OPERATION

After replacing the main body ECU with a normally functioning ECU, check that the engine starts.

OK: Steering lock/unlock function operates normally.

HINT:

If steering lock/unlock function does not operate, refer to PROBLEM SYMPTOMS TABLE of the electrical steering lock (steering wheel cannot be unlocked) (See PROBLEM SYMPTOMS TABLE ).

NG: GO TO ELECTRIC STEERING LOCK

OK: END (MAIN BODY ECU DEFECTIVE)