Pinpoint Test N: The Speed Sensitive Volume Does Not Operate Correctly
Information and Entertainment System
Pinpoint Tests
Pinpoint Test N: The Speed Sensitive Volume Does Not Operate Correctly
Refer to Wiring Diagram Set 130, Audio/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 Panel Cluster (IPC). The IPC 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).
- DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC) Control Module) - set by the ACM when the VSS signal is lost for greater than 5 seconds. When the signal is lost, the ACM turns the speed sensitive volume feature off.
- DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC) Control Module) - set by the audio DSP module when the VSS signal is lost for greater than 5 seconds. When the signal is lost, the speed sensitive volume feature is disabled.
This pinpoint test is intended to diagnose the following:
- Speed sensitive volume setting
- VSS signal concern
- ACM
- Audio DSP module
PINPOINT TEST N: THE SPEED SENSITIVE VOLUME DOES NOT OPERATE CORRECTLY
-------------------------------------------------
N1 CHECK THE SPEEDOMETER OPERATION
- Drive the vehicle and observe the speedometer.
- Does the speedometer operate correctly?
Yes
GO to N2.
No
REFER to Instrument Panel, Gauges and Warning Indicators.
-------------------------------------------------
N2 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 N3.
-------------------------------------------------
N3 CHECK FOR DTC U0155:00
NOTE: The SJB displays DTC U0155, rather than U0155:00.
- Clear the continuous DTCs from the ACM (vehicles without THX(R) sound), audio DSP module (vehicles with THX(R) sound), and the SJB.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds, and re-run the ACM (vehicles without THX(R) sound) or the audio DSP module (vehicles with THX(R) sound) self-test.
- Run the SJB self-test.
- Is DTC U0155:00 (or U0155) present in both audio system modules and the SJB?
Yes
GO to N6.
No
For vehicles without THX(R) sound, GO to N4.
For vehicles with THX(R) sound, GO to N5.
-------------------------------------------------
N4 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) 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. CLEAR any DTCs present. TEST the system for normal operation.
-------------------------------------------------
N5 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 determine if 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. CLEAR any DTCs present. TEST the system for normal operation.
-------------------------------------------------
N6 CHECK FOR CORRECT IPC OPERATION
- Disconnect the IPC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect IPC connector and make sure it seats correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IPC. CLEAR any DTCs present. 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 any DTCs present. TEST the system for normal operation.
-------------------------------------------------