Pinpoint Test U: The Audio Does Not Reduce When The Parking Aid Tone Sounds

Information and Entertainment System

Pinpoint Test U: The Audio Does Not Reduce When The Parking Aid Tone Sounds

Normal Operation

The Parking Aid Module (PAM) sends the volume cutback message to the Audio Control Module (ACM) via the Medium Speed Controller Area Network (MS-CAN). When the PAM (Parking Aid Module) sounds the parking aid tone, it broadcasts an enabled message to the ACM (Audio Control Module). When the ACM (Audio Control Module) receives this message, it reduces the speaker output so that the parking aid tone can be heard more clearly.

- DTC U0159 (Lost Communication With Parking Assist Control Module (PAM (Parking Aid Module)))- set by the non-navigation (Fusion) ACM (Audio Control Module) when the volume cutback message is missing for greater than 5 seconds. When the message is missing, the ACM (Audio Control Module) defaults to no volume cutback when the parking aid tone is sounding.

- DTC U0159:00 (Lost Communication With Parking Assist Control Module "A": No Sub Type Information)- set by the non-navigation (MKZ) or the navigation (all) ACM (Audio Control Module) when the volume cutback message is missing for greater than 5 seconds. When the message is missing, the ACM (Audio Control Module) defaults to no volume cutback when the parking aid tone is sounding.

This pinpoint test is intended to diagnose the following:

- Parking aid system concern

- ACM (Audio Control Module)

PINPOINT TEST U : THE AUDIO DOES NOT REDUCE WHEN THE PARKING AID TONE SOUNDS

U1 CHECK THE PARKING AID SIGNAL

- Apply the parking brake.

- Place an object behind the vehicle within the range of the parking aid sensors.

- Ignition ON.

- Place the transmission in REVERSE (R).

- Enter the following diagnostic mode on the scan tool: ACM (Audio Control Module) DataLogger.

- Monitor the parking aid input status PID (RPA_STAT) while the parking aid tone is sounding.

Does the PID read "Enabled" when the parking aid tone is sounding?

Yes
GO to U2.

No
REFER to Collision Avoidance and Parking Assist Systems to continue diagnosis of the parking aid system.

U2 CHECK FOR CORRECT ACM (Audio Control Module) OPERATION

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

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the ACM (Audio Control 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 ACM (Audio Control Module). REFER to Audio Control Module (ACM) - Fusion or Audio Control Module (ACM) - MKZ . 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.