Vehicle Proximity Notification System (Diagnostics & Circuit Tests): Overview Lexus GS IV

SYSTEM DESCRIPTION [03/2012 - ]

1. Vehicle Proximity Notification System When the vehicle is being driven under the power of just the HV Battery (hybrid engine is not running), the vehicle proximity notification system outputs a warning sound from the vehicle approaching speaker assembly to inform pedestrians, cyclists etc., of the approach of the vehicle. The warning sound is output by the vehicle approaching speaker assembly at a volume level that will not be perceived as noise. Also the pitch of the sound changes in accordance with vehicle speed so that the sound reflects vehicle deceleration and acceleration. Vehicle proximity notification system operation automatically stops when the vehicle is stopped, the engine starts or the vehicle is driven at 20 km/h (12 mph) or more.

OPERATION CHECK [03/2012 - ]

1. VEHICLE PROXIMITY NOTIFICATION SYSTEM OPERATION CHECK Check the system operation (when the vehicle is stationary). Check that the parking brake is applied. Turn the power switch on (IG). Check that the vehicle proximity notification system does not operate (e.g., does not sound) when the brake pedal is depressed and the shift lever is moved from P to N. Check that the vehicle proximity notification system operates (e.g., sounds) for approximately 3 seconds when the brake pedal is released. Check the system operation (when the vehicle is moving). Turn the power switch on (Ready). Operate the combination switch assembly (EV mode) to put the vehicle into EV driving mode. Check that the vehicle proximity notification system operates (e.g., sounds) when the shift lever is moved from P to D and the vehicle is being driven at 20 km/h or less in EV driving mode. Check that the vehicle proximity notification system does not operate (e.g., does not sound) when the shift lever is moved from D to P and the vehicle is stopped.

DESCRIPTION

When the vehicle approaching speaker controller detects that the shift lever is in P, vehicle approaching speaker operation is stopped. When the shift lever is in P, the power management controller sends a signal to the main body ECU (multiplex network body ECU) via the CAN communication line. This signal is then output to the vehicle approaching speaker controller.

Scheme 88

The vehicle approaching speaker controller detects brake operation through a signal from the No. 2 integration relay. When it is detected that the brake is not operating through a signal received from the stop light switch assembly via the No. 2 integration relay, vehicle approaching speaker operation is then possible.

Scheme 89

The vehicle approaching speaker controller detects that the engine is operating through a signal from the engine oil pressure switch assembly. When it is detected that the engine is operating via a signal from the engine oil pressure switch assembly, vehicle approaching speaker operation is stopped.

Scheme 90

The vehicle approaching speaker controller operates (e.g., sounds) the vehicle approaching speaker assembly during EV driving mode. The vehicle approaching speaker controller changes the pitch of the sound emitted from the speaker according to vehicle speed when the vehicle is being driven in EV driving mode.

Scheme 91

Scheme 92

1. CHECK VEHICLE APPROACHING SPEAKER CONTROLLER (OUTPUT WAVEFORM) TEXT IN ILLUSTRATION *a Front view of wire harness connector (to Vehicle Approaching Speaker Assembly) - - Check the output waveform. Disconnect the A49 vehicle approaching speaker assembly connector. Connect an oscilloscope to terminal A49-2 (+) and A49-1 (-). Check the signal waveform according to the condition(s) in the table below. Item Condition Tool setting 1 V/DIV., 200 ms./DIV. Vehicle condition Speaker operating* *: Use the operation check procedure to operate the speaker. Refer to «OPERATION CHECK [03/2012 - ]»(ref-600709-S04040711752014022400000) . OK The waveform is displayed as shown in the illustration. NG --> See step 2 OK --> See step 4
2. CHECK HARNESS AND CONNECTOR (VEHICLE APPROACHING SPEAKER CONTROLLER - VEHICLE APPROACHING SPEAKER ASSEMBLY) Disconnect the T35*1 or T43*2 vehicle approaching speaker controller connector. *1: w/ Night View System *2: w/o Night View System Disconnect the A49 vehicle approaching speaker assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance W/ NIGHT VIEW SYSTEM Tester Connection Condition Specified Condition T35-3 (SP+) - A49-2 (+) Always Below 1 ohms T35-8 (SP-) - A49-1 (-) Always Below 1 ohms T35-3 (SP+) - Body ground Always 10 kohms or higher T35-8 (SP-) - Body ground Always 10 kohms or higher W/O NIGHT VIEW SYSTEM Tester Connection Condition Specified Condition T43-3 (SP+) - A49-2 (+) Always Below 1 ohms T43-8 (SP-) - A49-1 (-) Always Below 1 ohms T43-3 (SP+) - Body ground Always 10 kohms or higher T43-8 (SP-) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 3
3. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600709-S20174603702014022400000)
4. REPLACE VEHICLE APPROACHING SPEAKER ASSEMBLY. Refer to «REMOVAL [03/2012 - ]»(ref-600686-S41500569222014022400000)

The vehicle proximity notification system may stop functioning properly if there is a power supply malfunction in the vehicle approaching speaker controller.

Scheme 93

See also:
• DIAGNOSIS SYSTEM [03/2012 - ]