DESCRIPTION
Speed signals are received from the combination meter assembly and used to cancel "Bluetooth" function operation.
The radio receiver assembly recognizes that the vehicle is being to driven and makes it impossible to connect or register a "Bluetooth" device while driving.
Tech Tips
A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.
If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the following diagram will not operate normally.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)
| *1 | Component with harness connected (Combination Meter Assembly) |
Check the output waveform.
Remove the combination meter assembly with the connector(s) still connected.
Connect an oscilloscope to terminal F15-3 (+S) and body ground.
Turn the power switch on (IG).
Turn a wheel slowly.
Check the signal waveform according to the condition(s) in the table below.
| Item | Condition |
|---|---|
| Measurement terminal | F15-3 (+S) - Body ground |
| Tool setting | 5 V/DIV., 20 ms./DIV. |
| Vehicle condition | Wheel being rotated |
| OK |
|---|
| The waveform is similar to that shown in the illustration. |
Tech Tips
When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.
| NG |
|
GO TO METER / GAUGE SYSTEM Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY)
| *1 | Front view of wire harness connector (to Radio Receiver Assembly) |
| *2 | Front view of wire harness connector (to Combination Meter Assembly) |
Disconnect the radio receiver assembly and combination meter assembly connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE RADIO RECEIVER ASSEMBLY Click here