Toyota RAV4 manuals

Toyota Sienna Service Manual: Identification of noise source

1. Radio Description

  1.  Radio frequency band
  1.  Radio broadcasts use the radio frequency bands shown in the table below.

Radio Description

  1. Service area

Radio Description

  1.  The service areas of AM and FM broadcasts are vastly different. Sometimes an AM broadcast can be received very clearly but an FM stereo cannot. FM stereo has the smallest service area, and is prone to pick up static and other types of interference such as noise.
  1.  Radio reception problems

HINT: In addition to static, other problems such as "phasing", "multipath", and "fade out" exist. These problems are not caused by electrical noise, but by the radio signal propagation method itself.

Radio Description

  1. Phasing
    AM broadcasts are susceptible to electrical interference and another kind of interference called phasing. Occurring only at night, phasing is the interference created when a vehicle receives 2 radio wave signals from the same transmitter. One signal is reflected off the ionosphere and the other signal is received directly from the transmitter

Radio Description

  1. Multipath
    Multipath is a type of interference created when a vehicle receives 2 radio wave signals from the same transmitter. One signal is reflected off buildings or mountains and the other signal is received directly from the transmitter.

Radio Description

  1. Fade out
    Fade out is caused by objects (buildings, mountains, and other such large obstacles) that deflect away part of a signal, resulting in a weaker signal when the object is between the transmitter and vehicle. High frequency radio waves, such as FM broadcasts, are easily deflected by obstructions. Low frequency radio waves, such as AM broadcasts, are much more difficult to deflect.
  1.  Noise problem
    Technicians must have a clear understanding about each customer's noise complaint. Use the following table to diagnose noise problems.

Radio Description

HINT: If the noise does not match the examples above, refer to the descriptions about phasing and multipath.

How to proceed with troubleshooting
1 VEHICLE BROUGHT TO WORKSHOP 2 INSPECT BATTERY VOLTAGE Standard voltage: 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding. 3 BASIC INSPECTION Turn ...

Problem symptoms table
HINT:  Before inspecting the suspected areas listed in the table below, check the fuse and relay.  Before inspecting the suspected areas listed in the table below, check for DTCs. ...

Other materials:

Active test
HINT: Performing an ACTIVE TEST enables components including the relays, VSV (Vacuum Switching Valve), and actuators, to be operated without removing any parts. The ACTIVE TEST can be performed with an intelligent tester. Performing an ACTIVE TEST in the first step in troubleshooting is one ...

Inspection
1. INSPECT SEAT HEATER SWITCH LH  Measure the resistance of the seat heater switch when the switch is operated. Resistance If the result is not as specified, replace the switch. HINT: As the dial is being turned, the resistance changes gradually.  Push the seat h ...

Disassembly
1. REMOVE FRONT SEAT SIDE TABLE LEG COVER (w/ Table)  Using a screwdriver, disengage the claws and remove the seat side table leg cover. HINT: Tape the screwdriver tip before use. 2. REMOVE FRONT SEAT SIDE TABLE (w/ Table)  Remove the 4 nuts and seat side table.  Rem ...

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