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:

Cruise Main Indicator Light Circuit
DESCRIPTION  The ECM detects a cruise control switch signal and sends it to the combination meter through CAN and BEAN. Then the CRUISE main indicator light comes on.  The CRUISE main indicator light circuit uses CAN and BEAN for communication. If there is a malfunction in ...

Brake Switch "A" Circuit
DTC P0571 Brake Switch "A" Circuit DESCRIPTION When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM receives this signal, it cancels the cruise control. The fail-safe function operates to enable normal driving even if there is a malfuncti ...

Definition of terms
Term Definition Monitor description Description of what the ecm monitors and how it detects malfunctions (monitoring purpose and its details). Related dtcs Diagnostic codeV Typical enabling condition Preconditions that allow the ecm to detect malfunc ...

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