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 sounds the parking aid tone, it broadcasts an enabled message to the ACM. When the ACM 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)) - set by the non-navigation (Fusion, Milan) ACM when the volume cutback message is missing for greater than 5 seconds. When the message is missing, the ACM 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 when the volume cutback message is missing for greater than 5 seconds. When the message is missing, the ACM 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


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

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U1 CHECK THE PARKING AID SIGNAL

- Apply the parking brake.
- Place an object behind the vehicle within the range of the parking aid sensors. Refer to Parking Aid Specifications.
- Ignition ON.
- Place the transmission in REVERSE (R).
- Enter the following diagnostic mode on the scan tool: ACM 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 Parking Aid Testing and Inspection to continue diagnosis of the parking aid system.

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U2 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) - Fusion, Milan Audio Control Module (ACM) or Audio Control Module (ACM) - MKZ 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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