Important: Electronic modules with an undiagnosed problem may cause Electromagnetic Interference (EMI). An EMI condition may cause radio reception interference.

1. Verify the customer's complaint with the station(s) that are normally received in your area.
2. Compare the complaint vehicle with a similar vehicle in the same locations that the concern is observed.

Does the radio reception of both vehicles perform the same?

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Go to Step 2

Go to Step 3

Explain to customer the normal operation of the radio observed in both vehicles.

Is the explanation complete?

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System OK

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1. Move vehicle outside away from any electrical interference such as electric motors, fluorescent lighting, etc.
2. Disconnect the coaxial cable from the radio.
3. Temporarily mount a test antenna to the vehicle.
4. Ground the antenna base and test the ground with a DMM before plugging the coax into the radio.
5. Connect the coaxial cable.
6. Do not hold the antenna in your hand.
7. Turn radio on and tune to a strong radio station.

Does the reception improve?

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Go to Step 4

Go to Step 5

Replace the antenna assembly. Refer to Radio Antenna Replacement .

Is the replacement complete?

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Go to Radio/Audio System Check

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Is there any aftermarket wiring present?

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Go to Step 6

Go to Step 8

Temporarily disconnect aftermarket wiring (both the battery and ground connections.

Does the radio reception improve?

--

Go to Step 7

Go to Step 8

Remove the aftermarket wiring.

Is the repair complete?

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Go to Radio/Audio System Check

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Compare the radio reception with the ignition switch in the following positions:

Does the radio reception change with the key in the ON position (engine not running) or in the ON position (engine running)?

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Go to Step 9

Go to Step 11

Was the radio reception degraded with the ignition key in the ON position (engine not running)?

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Go to Step 11

Go to Step 10

Was the radio reception degraded with the ignition key in the ON position (engine running)?

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Go to Step 11

Go to Step 13

Test for Electromagnetic Interference (EMI) - (See Important).

Was an EMI condition found in an electronic module?

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Go to Step 12

Go to Step 13

Replace the faulty module.

Has the radio reception improved?

--

Go to Radio/Audio System Check

Go to Step 13

Using J 39200 set to measure AC voltage, connect the positive lead to the negative battery terminal and the negative lead of the DMM to a non-painted surface in the engine compartment. Is the AC voltage less than the specified value?

25 mV

Go to Step 15

Go to Step 14

Repair the poor ground condition in one or more of the following ground connections:

Refer to Power and Grounding Components in Wiring Systems for locations.

Is the repair(s) complete?

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Go to Step 21

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Using J 39200 set to measure AC voltage, connect the positive lead to the negative battery terminal and the negative lead to a non-painted surface of the A-pillar.

Was the AC voltage less than the specified value?

25 mV

Go to Step 17

Go to Step 16

Repair the poor ground condition in one or more of the following ground connections:

Refer to Power and Grounding Components in Wiring Systems for locations.

Is the repair(s) complete?

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Go to Step 21

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Using J 39200 set to measure AC voltage, connect the positive lead to the negative battery terminal and the negative lead to a non-painted surface of the B-pillar.

Was the AC voltage less than the specified value?

25 mV

Go to Step 19

Go to Step 18

Repair the poor ground condition in one or more of the following ground connections:

Refer to Power and Grounding Components for locations.

Is the repair complete?

--

Go to Step 21

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Using J 39200 set to measure AC voltage, connect the positive lead to the Negative battery terminal and the negative lead to a non-painted surface in the luggage compartment.

Was the AC voltage less than the specified value?

25 mV

Go to Step 22

Go to Step 20

Repair the poor ground connection at G400. Refer to Power and Grounding Components in Wiring Systems for locations.

Is the repair complete?

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Go to Step 21

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Has the radio reception improved?

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Go to Radio/Audio System Check

Go to Step 22

Replace the radio. Refer to Radio Replacement .

Is the replacement complete?

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Go to Radio/Audio System Check

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