Pinpoint Test B: Poor Reception
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Reception
Normal Operation
The audio unit antenna receives AM and FM radio signals. The radio signals are sent to the audio unit through the audio unit antenna lead-in cable.
The noise suppression equipment reduces interference transmitted through the speakers by the engine ignition and electrical systems. When installing any new audio unit suppression equipment components, make sure that a good contact is made at all connections. Remove any paint or dirt from between a component and its ground. Tighten all connectors and fasteners securely.
- DTC B2103 TUNER (Antenna Not Connected) - sets when the signal strength is less than a pre-determined value during the "antenna connected test" portion of the audio unit 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
- Noise suppression equipment
- Ignition system
- Charging system
- Radio ignition interference capacitor
- Audio unit
PINPOINT TEST B: POOR RECEPTION
NOTICE: For the CD6 audio unit, the audio unit must be placed in shipment mode before removal. Refer to Audio Unit Shipment Mode Audio Unit Shipment Mode. Failure to follow this instruction may result in damage to the audio unit.
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B1 CHECK THE AUDIO UNIT RECEPTION
- Check the audio unit reception with the engine running, and with the engine off.
- Does the poor reception only occur with the engine running?
Yes
GO to B2.
No
GO to B6.
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B2 CHECK THE SUPPRESSION EQUIPMENT/MOUNTING AND CONNECTING CIRCUITS
- Check all necessary suppression equipment and the radio frequency interference suppression bond.
- Check the audio unit receiver hood bonding strap (part of the RH hood hinge) and the body-to-chassis strap for integrity, cleanliness, and metal-to-metal contact.
- 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 ignition interference capacitor for integrity, cleanliness, and metal-to-metal contact.
- Are the connections clean, secure, and in metal-to-metal contact?
Yes
GO to B3.
No
CLEAN, SECURE, or INSTALL new suppression equipment as necessary. TEST the system for normal operation.
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B3 CHECK THE RADIO IGNITION INTERFERENCE CAPACITOR
- Ignition OFF.
- Check the operation of the radio ignition interference capacitor by installing a known good component.
- Start the vehicle.
- Operate the audio unit in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new radio ignition interference capacitor. TEST the system for normal operation.
No
INSTALL the original radio ignition interference capacitor. GO to B4.
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B4 CHECK THE GENERATOR
- Ignition OFF.
- Check the generator by disconnecting the voltage regulator.
- Start the vehicle.
- Operate the audio unit in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new generator. REFER to Charging System. TEST the system for normal operation.
No
CONNECT the voltage regulator. GO to B5.
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B5 CHECK THE IGNITION CIRCUITS
- Ignition OFF.
- Check the ignition circuits for correct routing, grounding, and integrity of connections.
- Check the spark plugs and the spark plug wires.
- Are the ignition components OK?
Yes
GO to B10.
No
REPAIR the ignition system as necessary. TEST the system for normal operation.
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B6 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 B8.
No
GO to B7.
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B7 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 B8.
No
CLEAN and SECURE the antenna connections as necessary. TEST the system for normal operation.
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B8 SUBSTITUTE THE ANTENNA
- Substitute a known good antenna. Ground the antenna base to an unpainted metal surface on the vehicle.
- Ignition ON.
- Operate the audio unit in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new antenna. REFER to Antenna Antenna. TEST the system for normal operation.
No
INSTALL the original antenna. GO to B9.
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B9 SUBSTITUTE THE ANTENNA CABLE
- Ignition OFF.
- Substitute a known good antenna cable.
- Ignition ON.
- Operate the audio unit in radio tuner (AM/FM) mode.
- Is the reception OK?
Yes
INSTALL a new antenna cable. REFER to Antenna Cable Antenna Cable. TEST the system for normal operation.
No
INSTALL the original antenna cable. GO to B10.
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B10 SUBSTITUTE THE AUDIO UNIT
- Ignition OFF.
- Substitute a known good audio unit.
- Start the vehicle.
- Verify the operation of the audio unit.
- Is the reception OK?
Yes
INSTALL a new audio unit. REFER to Audio Unit Audio Unit. TEST the system for normal operation.
No
INSTALL the original audio unit. GO to B11.
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B11 REPOSITION THE COMPONENTS
- Ignition OFF.
- Determine if the noise can be eliminated by repositioning the antenna cable, speaker circuits, or audio unit power feed circuits away from other circuits or brackets.
- Start the vehicle.
- Verify the operation of the audio unit.
- Is the reception OK?
Yes
Permanently REPOSITION the components as needed. TEST the system for normal operation.
No
GROUND various parts of the vehicle to the frame using a jumper cable. When the noise is corrected, PROVIDE a permanent ground where necessary. TEST the system for normal operation.
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