Pinpoint Test Y: The Speed Sensitive Volume Does Not Operate Correctly
Information and Entertainment System
Pinpoint Tests
Pinpoint Test Y: The Speed Sensitive Volume Does Not Operate Correctly
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
Normal Operation
The speed sensitive volume function adjusts the volume based on the Vehicle Speed Sensor (VSS) signal from the Instrument Cluster (IC). The IC does not generate the VSS signal; it gateways the signal from the PCM. The Smart Junction Box (SJB) also receives this signal and should exhibit symptoms if the signal is lost.
For vehicles without THX(R) audio, the Audio Control Module (ACM) controls the speed sensitive volume function.
For vehicles with THX(R) audio, the audio Digital Signal Processing (DSP) module controls the speed sensitive volume function. The ACM sends the speed sensitive volume setting to the audio DSP module via the Medium Speed Controller Area Network (MS-CAN).
This pinpoint test is intended to diagnose the following:
- Speed sensitive volume setting
- VSS signal concern
- Communication network concern
- ACM
- Audio DSP module
PINPOINT TEST Y: THE SPEED SENSITIVE VOLUME DOES NOT OPERATE CORRECTLY
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Y1 CHECK THE SPEEDOMETER OPERATION
- Drive the vehicle and observe the speedometer.
- Does the speedometer operate correctly?
Yes
GO to Y2.
No
REFER to Instrument Panel, Gauges and Warning Indicators.
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Y2 CHECK THE SPEED SENSITIVE VOLUME SETTING
- Turn the speed sensitive volume off. Refer to the Owner's Literature.
- Operate the audio system in radio tuner (AM/FM) mode.
- Drive the vehicle at various speeds and observe the speaker volume.
- Set the speed sensitive volume to maximum compensation. Refer to the Owner's Literature.
- Operate the audio system in radio tuner (AM/FM) mode.
- Drive the vehicle at various speeds and observe the speaker volume.
- Does the volume remain constant with the speed sensitive volume turned off, and increase and decrease with vehicle speed with the speed sensitive volume set to maximum?
Yes
The system is operating correctly at this time. INSTRUCT the customer in the correct usage of the speed sensitive volume feature.
No
GO to Y3.
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Y3 CHECK FOR DTC U0155, U0155:00, U0184, OR U0184:00
- Using the scan tool, retrieve all continuous DTCs.
- Is DTC U0155, U0155:00, U0184 (THX(R) only), or U0184:00 (THX(R) only) retrieved in any audio system module?
Yes
For DTC U0155 or DTC U0155:00, Go To Pinpoint Test AD. Pinpoint Test AD: DTC U0155 Or DTC U0155:00
For DTC U0184 or DTC U0184:00, Go To Pinpoint Test AE. Pinpoint Test AE: DTC U0184 Or DTC U0184:00
No
For vehicles with THX(R) sound, GO to Y5.
For all others, GO to Y4.
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Y4 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 verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ACM. REFER to Audio Control Module (ACM) Audio Control Module (ACM). 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.
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Y5 CHECK FOR CORRECT AUDIO DSP MODULE OPERATION
- Disconnect all the audio DSP module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the audio DSP module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new audio DSP module. REFER to Audio Digital Signal Processing (DSP) Module Audio Digital Signal Processing (DSP) Module. 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.
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