Pinpoint Test B: Poor Reception
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Reception
Normal Operation
Audio waves are received by the antenna and transferred to the audio unit through the antenna cables. The radio suppression equipment reduces interference caused by the electrical components of the ignition and charging systems. When the SEEK/SCAN button is pressed, the audio unit searches for a channel with sufficient audio signal strength and automatically stops when it reaches such a channel.
This pinpoint test is intended to diagnose the following:
- Noise suppression equipment
- Antenna
- Antenna connections
- Antenna cable
- Charging system
- Ignition system
- Audio unit
PINPOINT TEST B: POOR RECEPTION
-------------------------------------------------
B1 CHECK THE RADIO RECEPTION
- Check the audio unit signal 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 B8.
-------------------------------------------------
B2 CHECK THE SUPPRESSION EQUIPMENT
- Check all necessary suppression equipment, the radio frequency interference suppression bond and the radio receiver hood bonding strap for security, cleanliness, and metal-to-metal contact.
- Are the contacts clean, secure, and in metal-to-metal contact?
Yes
GO to B3.
No
INSTALL new radio frequency interference suppression bonds or related equipment, or CLEAN and SECURE the connections as necessary. TEST the system for normal operation.
-------------------------------------------------
B3 CHECK THE CAPACITOR MOUNTING AND CONNECTING CIRCUITS
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(s) for security, cleanliness, and metal-to-metal contact.
- Are the contacts clean, secure, and in metal-to-metal contact?
Yes
GO to B4.
No
CLEAN or SECURE the connections as necessary. TEST the system for normal operation.
-------------------------------------------------
B4 CHECK THE RADIO IGNITION INTERFERENCE CAPACITOR(S) AND GENERATOR
- Check the operation of the radio ignition interference capacitor(s) by installing known good component(s).
- Check the generator by disconnecting the wiring harness from the voltage regulator.
- Start the engine.
- Verify the operation of the audio unit.
- Is the reception OK?
Yes
REPAIR or INSTALL new components as necessary. TEST the system for normal operation.
No
GO to B5.
-------------------------------------------------
B5 CHECK THE IGNITION CIRCUITS
- Ignition OFF.
- Check the ignition circuits for correct routing, grounding, and security of connections.
- Are the circuits OK?
Yes
GO to B6.
No
REPAIR the circuits as necessary. TEST the system for normal operation.
-------------------------------------------------
B6 CHECK THE IGNITION SYSTEM
- Test the ignition system.
- Is the ignition system OK?
Yes
GO to B7.
No
REPAIR the ignition system. TEST the system for normal operation.
-------------------------------------------------
B7 SUBSTITUTE THE AUDIO UNIT
- Ignition OFF.
- Substitute a known good audio unit.
- Start the engine.
- Verify the operation of the audio unit.
- Is the reception OK?
Yes
INSTALL a new audio unit. REFER to Audio Unit Service and Repair. TEST the system for normal operation.
No
INSTALL the original audio unit. USE a jumper cable to ground various parts of the vehicle to the frame (for example, the engine, fenders, quarter panels, stone deflectors, engine air cleaner or body sheet metal). When the noise is eliminated, PROVIDE a permanent ground where necessary. TEST the system for normal operation.
-------------------------------------------------
B8 CHECK THE ON-GLASS ANTENNA
- Disconnect: Antenna Lead Terminal.
- Measure the resistance between the antenna cable lead terminal and the antenna grid wire.
- Is the resistance less than 8 ohms?
Yes
GO to B9.
No
REPAIR the grid lines as necessary. REFER to Windows and Glass. TEST the system for normal operation.
-------------------------------------------------
B9 SUBSTITUTE THE ANTENNA EXTENSION CABLE
- Ignition OFF.
- Substitute a known good antenna cable.
- Start the engine.
- Verify the operation of the audio unit.
- Is the reception OK?
Yes
INSTALL a new antenna cable. REFER to Antenna Lead-In Cable Service and Repair. TEST the system for normal operation.
No
INSTALL the original antenna cable. GO to B10 .
-------------------------------------------------
B10 SUBSTITUTE THE ANTENNA MODULE
- Ignition OFF.
- Substitute a known good antenna module.
- Start the engine.
- Check the operation of the audio unit.
- Is the reception OK?
Yes
INSTALL a new antenna module. REFER to Antenna Module Service and Repair. TEST the system for normal operation.
No
INSTALL the original antenna module. INSTALL a new audio unit. REFER to Audio Unit Service and Repair. TEST the system for normal operation.
-------------------------------------------------