Pinpoint Test A: Poor Reception - AM/FM
Information and Entertainment System
Pinpoint Tests
Pinpoint Test A: Poor Reception - AM/FM
Normal Operation
The noise suppression equipment reduces interference transmitted through the speakers by the engine ignition and electrical systems.
- DTC B2103 (Antenna Not Connected) - sets when the signal strength is less than a pre-determined value during the "antenna connected test" portion of the Audio Control Module (ACM) self-test. This DTC may not set, even if there is an open in the antenna coaxial cable; however, if it does set, the antenna circuit can be isolated for diagnosis.
This pinpoint test is intended to diagnose the following:
- Antenna
- Antenna cable(s)
- Charging system
- Ignition system
- Noise suppression equipment
- ACM
PINPOINT TEST A: POOR RECEPTION - AM/FM
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A1 REVIEW THE DTCs
- Review the DTCs from the ACM self-test.
- Is DTC B2103 present?
Yes
GO to A7.
No
GO to A2.
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A2 CHECK THE AUDIO SYSTEM RECEPTION
- Check the ACM signal reception with the engine running, and with the engine off.
- Does the poor reception only occur with the engine running?
Yes
GO to A3.
No
GO to A7.
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A3 CHECK THE SUPPRESSION EQUIPMENT/MOUNTING AND CONNECTING CIRCUITS
- Ignition OFF.
- Check all necessary suppression equipment and the radio frequency interference suppression bond.
- NOTE: The capacitor mounting points are used to complete the electrical circuit and must be mounted securely to clean surfaces.
- Check the mounting and connecting circuits of the radio interference capacitor for integrity, cleanliness, and metal-to-metal contact.
- Are the connections clean, secure, and in metal-to-metal contact?
Yes
GO to A4.
No
CLEAN, SECURE, or INSTALL new suppression equipment as necessary. TEST the system for normal operation.
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A4 CHECK THE RADIO INTERFERENCE CAPACITOR
- Check the operation of the radio interference capacitor by installing a known good component.
- Start the vehicle.
- Operate the audio system in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new radio interference capacitor. TEST the system for normal operation.
No
INSTALL the original radio interference capacitor. GO to A5.
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A5 CHECK THE GENERATOR
- Ignition OFF.
- Check the generator by disconnecting the voltage regulator.
- Start the vehicle.
- Operate the audio system in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new generator. TEST the system for normal operation.
No
TURN the key to OFF. CONNECT the voltage regulator. GO to A6.
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A6 CHECK THE IGNITION CIRCUITS
- Check the ignition circuits for correct routing, ground, and integrity of connections.
- Check the spark plugs and ignition coils.
- Are the ignition components OK?
Yes
GO to A10.
No
REPAIR the ignition system as necessary. TEST the system for normal operation.
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A7 CHECK THE ANTENNA GROUND
- Ignition OFF.
- Measure the resistance between the antenna base and the battery ground cable.
- Is the resistance less than 5 ohms?
Yes
GO to A9.
No
GO to A8.
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A8 CHECK THE ANTENNA CABLE CONNECTIONS
- Check the antenna connections, including the extension cable.
- Check to make sure the antenna is securely mounted to the vehicle body at ground points.
- Are the connections clean, secure, and in metal-to-metal contact?
Yes
GO to A9.
No
CLEAN and SECURE the antenna connections as necessary. CLEAR the DTCs. REPEAT the self-test.
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A9 SUBSTITUTE THE ANTENNA
- Substitute a known good antenna.
- Ignition ON.
- Operate the audio system in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new antenna. CLEAR the DTCs. REPEAT the self-test.
No
TURN the key to OFF. INSTALL the original antenna. GO to A10 .
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A10 SUBSTITUTE THE ANTENNA CABLE
- Substitute a known good antenna cable.
- Ignition ON.
- Operate the audio system in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new antenna cable. REFER to Antenna Lead-In Cable Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
TURN the key to OFF. INSTALL the original antenna cable. GO to A11 .
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A11 CHECK FOR CORRECT ACM OPERATION
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ACM. REFER to Audio Control Module (ACM) Removal and Replacement. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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