Pinpoint Test D: Radio Interference
NOTE:
If the Original Equipment Manufacturer (OEM) Audio Control Module (ACM) has been replaced with an aftermarket unit, the vehicle may not pass this test. Return the vehicle to Original Equipment Manufacturer (OEM) condition before following this pinpoint test.
NOTE:
Make sure the engine rpm stays below 2, 000 Revolutions Per Minute (RPM) when the generator is disconnected. If it rises above 2, 000 Revolutions Per Minute (RPM) the generator may self-excite. If this occurs, turn the ignition to the OFF position and start the test over again.
- NOTE: Inspect for any aftermarket accessories that have been added to the vehicle. Check the wiring for these accessories and be sure they have not been attached to the generator circuits and are positioned away from the generator wiring.
Refer to Charging System for schematic and connector information.
Normal Operation and Fault Conditions
The generator radio suppression equipment reduces interference transmitted through the speakers by the vehicle electrical system.
Possible Sources
- Generator
- In-vehicle entertainment system
- Wiring, terminals or connectors
Visual Inspection and Pre-checks
- Inspect the generator.
- Inspect the in-vehicle entertainment system.
- D1 VERIFY THE GENERATOR IS THE SOURCE OF THE AUDIO SYSTEM INTERFERENCE
- Start the engine.
- Allow the engine to idle.
- Tune the audio system to a station where interference is present.
- Ignition OFF.
- Disconnect Generator C102A.
- Disconnect Generator C102A.
- Start the engine.
- Allow the engine to idle.
Is the interference present with the generator disconnected?
Yes DIAGNOSE the audio system. Refer to the appropriate Information and Entertainment System article for the procedure. No INSTALL a new generator. REFER to: Generator .