Pinpoint Test I: The Speed Sensitive Volume Does Not Operate Correctly

Information and Entertainment System

Pinpoint Test I: The Speed Sensitive Volume Does Not Operate Correctly

Normal Operation

The speed sensitive volume function, available with all audio systems except the base AM/FM radio, adjusts the volume based on the Vehicle Speed Sensor (VSS) signal from the Body Control Module (BCM). The BCM (Body Control Module) gateways the VSS (Vehicle Speed Sensor) signal from the PCM.

Additionally, when a MyKey(R) is in the ignition and the MyKey(R) volume limiter is turned on, speed sensitive volume is disabled. This is normal operation. Make sure an administrator key is being used to verify the concern.

This pinpoint test is intended to diagnose the following:

- Speed sensitive volume setting

- VSS (Vehicle Speed Sensor) signal concern

- Communication network concern

- ACM (Audio Front Control Module)

PINPOINT TEST I : THE SPEED SENSITIVE VOLUME DOES NOT OPERATE CORRECTLY

I1 CHECK THE SPEEDOMETER OPERATION

- Drive the vehicle and observe the speedometer.

Does the speedometer operate correctly?

Yes
GO to I2.
No
REFER to Instrument Panel, Gauges and Warning Indicators.

I2 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 on the correct usage of the speed sensitive volume feature.
No
GO to I3.

I3 CHECK FOR DTC U0155 OR DTC U0155:00

- Clear the continuous DTCs from the ACM (Audio Front Control Module) and the BCM (Body Control Module).

- Ignition OFF.

- Ignition ON.

- Wait 10 seconds and re-run the ACM (Audio Front Control Module) self-test.

- Run the BCM (Body Control Module) self-test.

Is DTC U0155:00 (or U0155) present in any module?

Yes
GO to Pinpoint Test AI. Pinpoint Test AI: DTC U0155 Or DTC U0155:00
No
GO to I4.

I4 CHECK FOR CORRECT ACM (Audio Front Control Module) OPERATION

- Disconnect all the ACM (Audio Front Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the ACM (Audio Front Control 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 ACM (Audio Front Control Module). REFER to 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.