Toyota 4Runner: Diagnosis System

DIAGNOSIS SYSTEM

1. DESCRIPTION

(a) When troubleshooting a vehicle with a diagnosis system, connect the Techstream to the DLC3 of the vehicle and read various data output from the steering lock actuator assembly (steering lock ECU).

The steering lock actuator assembly (steering lock ECU) stores DTCs when the ECU detects a malfunction in itself or in its circuits.

(b) The diagnosis information of the steering lock actuator assembly (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.

(c) The steering lock actuator assembly (steering lock ECU) does not store DTCs regarding past problems.

(d) When the engine switch is off, the main body ECU may occasionally go into a non-active state called sleep mode. Communication with the Techstream is not possible if the main body ECU is in 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.

(e) As the steering lock actuator assembly (steering lock ECU) memory data is cleared, do not remove the fuses or disconnect the cable from the battery terminals until the DTCs are checked and noted.

(f) Malfunctions related to systems other than the steering lock actuator assembly (steering lock ECU) system may cause DTCs to be output. Note any DTCs related to other systems.