Bulletin No.: PIT5507D
Published date: 03/27/2018

Preliminary Information
PIT5507D Unwanted Or False Alerts / Park Assist Off Message / Service Park Assist Message At Start
Up With DTC U0159
Product Investigation Review Required
Models
Brand:

Model:

Model Years:

VIN:
from

Engine:

to

Transmissions:

Cadillac

Escalade

2015 - 2018

All

All

All

All

Chevrolet

Silverado 1500

2014 - 2018

All

All

All

All

Chevrolet

Silverado 2500/3500

2015 - 2018

All

All

All

All

Chevrolet

Suburban

2015 - 2018

All

All

All

All

Chevrolet

Tahoe

2015 - 2018

All

All

All

All

GMC

Sierra 1500

2014 - 2018

All

All

All

All

GMC

Sierra 2500/3500

2015 - 2018

All

All

All

All

GMC

Yukon

2015 - 2018

All

All

All

All

Supersession Statement
With Ultrasonic Park Assist System (RPO UD5 or UD7)

Supersession Statement
This PI was superseded to update the model year, Condition, Recommendation. Please discard PIT5507C.

Condition / Concern
Some owners may comment on any of the following Parking Assist System issues:
1. (This concern only applies to 2014 - 2016 models) Unwanted/false alerts suggesting there is an object in front and/or behind the
vehicle when there is nothing there. This issue is more prevalent when it is raining or snowing.
2. (This concern only applies to 2016 models) At times when the truck is first started, there is a "Service Parking Assist" message
displayed. If the ignition is cycled off and back on, the message will be gone. When scanning for DTC's, a U0159 will be set in the IPC
and/or BCM. This concern only occurs at start up and is very random.
3. (This concern applies to all models listed) Unwanted/false front park assist alerts suggesting there is an object in front and/or
behind the vehicle when there is nothing there. In some cases, there may be a "Park Assist Off" message displayed in the DIC and the
park assist switch LED will be disabled.

Recommendations / Instructions
Conditions 1 and 2 - Engineering has developed updated Parking Assist Control Module (K41/K86) calibrations to correct these
concerns. Reprogram the Parking Assist Control Module (K41/K86) with the latest calibrations currently available in TIS2WEB.
Condition 3 - Listed below are a number of factors that can cause unwanted/false park assist alerts:
Tip: Question the driver when the unwanted/false park assist alert occurs. Find out where does the DIC parking assist display show
the object is located? This information is very helpful to narrow down which sensors should be inspected. Example: the DIC parking
assist display shows the left front is indicating that something is present, but there is nothing there. Knowing that information will
help determine which sensors/rings to inspect more closely.
- Improper painting of the sensor tip. The tip of the sensor is isolated from the body of the sensor and there should be a small
amount of movement between the tip of the sensor and body of the sensor. If the area shown below is painted, it will bridge the gap
between the tip of the sensor and sensor body. This will cause a ground out or transmission path between the tip of the sensor and
sensor body. In addition, excessive paint thickness on the tip of the sensor can trigger false alerts.

- A new scalloped sensor ring has been released to replace the old non-scalloped sensor ring, as shown below. When servicing a
sensor or sensor ring, there are benefits to using the new scalloped sensor rings, GM P/N 84075238, in place of the old non-scalloped
sensor ring.
Note: The 2016 - 2017 model year Silverado 1500 and Sierra 1500 models were the first full size truck models to use the new
scalloped sensor rings. They were used for the front sensors, and due to the bezel design, the old non-scalloped sensor rings can
not be used or false alerts can occur. There have been reports of replacement front park assist sensors coming with the old nonscalloped sensor rings. If the old non-scalloped sensor rings were installed on these vehicles, it will cause unwanted/false front park
assist alerts. This can lead to a "Park Assist Off" message being displayed. If the front sensor rings are found to be the old nonscalloped sensor rings, replace the sensor rings with the new scalloped design, GM part number 84075328.

- It is imperative when installing the new scalloped sensor rings to pay close attention that are installed onto the sensor correctly, as
shown below (1).

- When the sensor and ring are installed into the bumper/bezel, care should be taken to make sure they are installed without any
binding/misalignment/etc. If the sensor and/or sensor ring is not properly installed it can cause the tip of the senor to have a direct
transmission path with the bezel/bumper/fascia and trigger unwanted/false alerts. Shown below, is one example of an improperly
installed sensor ring. The ring was rolled when the sensor was installed.

Note: Remember even with the updated calibrations and updated sensor rings are installed, the park assist system could give false
alerts and disable. Below are examples which can effect system operation. To prevent injury, death, or vehicle damage, even with
Parking Assist, always check the area around the vehicle and check all mirrors before moving forward or backing.
- The Rear Park Assist will not work properly if the tailgate is down. If the tailgate is down, do not use the park assist systems and in
some cases the "Park Assist Off" message may display.
- If an object is attached to the rear of the vehicle, such as a trailer, bicycle rack, trailer hitch receiver, or tow bar. Also, an object
extending beyond a lowered tailgate will disable the system.
- If an object is attached to the front of the vehicle, such as brush guard, cattle guard, bully guard, lights, snow plow, hitch, push bar,
bicycle rack, etc.
- If the parking assist sensors are covered by snow, mud, dirt, slush, ice, heavy rain, etc.
- The vehicle bumper is damaged.
- Excessive paint thickness on a replacement parking assist sensor.
- The parking assist sensors are disrupted by vibrations, like those caused by a large nearby vehicle, heavy equipment such as a
jackhammer, aftermarket horns or siren, etc.

Parts Information
Part Number

Description

Qty

84075328

Front Park Assist Sensor Ring

As Needed

Labor Operation

Description

Labor Time

2810375

Parking Assist Control Module Reprogramming with SPS

Use Published Labor Time

Warranty Information

6420260

Front Parking Assist Alarm Sensor Replacement

Use Published Labor Time

6420280

Rear Parking Assist Alarm Sensor Replacement

Use Published Labor Time

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved
without completing every step, the remaining steps do not need to be performed.

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