For 1990-2009 cars

Step | Action | Value | Yes | No
--- | --- | --- | --- | ---
Important: Refer to SIR Handling Caution in Cautions and Notices. Electronic modules with an undiagnosed problem may cause Electromagnetic Interference (EMI). An EMI condition may cause radio reception interference. To test for the presence of EMI in a module, systematically disconnect the electronic module connectors one at a time (turn the ignition switch to OFF before disconnecting each module) and note any improvement in radio reception. Do Not disconnect the Inflatable Restraint Sensing and Diagnostic Module (SDM).
1 | Did you review the Radio/Audio System Operation and perform the necessary inspections? | -- | Go to Step 2 | Go to Symptoms - Entertainment
2 | Verify that the radio has poor reception. Does the radio operate normally? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3
3 |

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?

--

Go to Step 4

Go to Step 5

4 | Explain to customer the normal operation of the radio observed in both vehicles. Is the explanation complete? | -- | System OK | --
5 |

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?

--

Go to Step 6

Go to Step 7

6 | Replace the Antenna assembly. Refer to Radio Antenna Replacement . Is the replacement complete? | -- | Go to Step 23 | --
7 | Refer to Checking Aftermarket Accessories in Wiring Systems. Is any aftermarket wiring present? | -- | Go to Step 8 | Go to Step 10
8 | Temporarily disconnect aftermarket wiring (both the battery and ground connections. Does the radio reception improve? | -- | Go to Step 9 | Go to Step 10
9 | Remove the aftermarket wiring. Is the repair complete? | -- | Go to Step 21 | --
10 | Compare the radio reception with the ignition switch in the following positions:

• | ACC

• | ON (engine not running).

• | ON (engine running).

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

--

Go to Step 11

Go to Step 13

11 | Was the radio reception degraded with the ignition key in the ON position (engine not running)? | -- | Go to Step 13 | Go to Step 12
12 | Was the radio reception degraded with the ignition key in the ON position (engine running)? | -- | Go to Step 13 | Go to Step 15
13 | Test for Electromagnetic Interference (EMI) - (See Note). Was an EMI condition found in an electronic module? | -- | Go to Step 14 | Go to Step 15
14 | Replace the faulty module. Has the radio reception improved? | -- | System OK | Go to Step 15
15 | 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 17 | Go to Step 16
16 | Repair the poor ground condition in one or more of the following ground connections:

• | G100

• | G101

• | G102

• | G103

• | G104

• | G105

Refer to Harness Routing Views in Wiring Systems for locations.

Is the repair(s) complete?

--

Go to Step 21

--

17 | 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. Is the AC voltage less than the specified value? | 25 mV | Go to Step 19 | Go to Step 18
18 | Repair the poor ground condition in one or more of the following ground connections:

• | G200

• | G201

• | G202

Refer to Harness Routing Views in Wiring Systems for locations.

Is the repair(s) complete?

--

Go to Step 21

--

19 | 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 rear door. Is the AC voltage less than the specified value? | 25 mV | Go to Step 22 | Go to Step 20
20 | Repair the poor ground condition at one or more of the following ground connections:

• | G400

• | G401

Refer to Harness Routing Views in Wiring Systems for locations.

Is the repair(s) complete?

--

Go to Step 21

--

21 | Has the radio reception improved? | -- | Go to Step 23 | Go to Step 22
22 | Replace the radio. Refer to Radio Replacement . Is the replacement complete? | -- | Go to Step 23 | --
23 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 3