Engineering Information – Head Up Display (HUD) Blank, DTC U1518 Set – 2020-2021 Cadillac

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Subject: Engineering Information – Head Up Display (HUD) Blank, DTC U1518 Set
Attention: Proceed with this EI ONLY if the customer has commented about this concern AND the PIE number is listed in the
Global Warranty Management / Investigate History link (GWM/IVH). If the customer has not commented about this
condition or the EI does not show in GWM/IVH, disregard the PIE and proceed with diagnostics found in published
service information. THIS IS NOT A RECALL — refer to Service Bulletin 04-00-89-053 for more details on the use of
Engineering Information bulletins.
This EI has been revised to add 2020-2021 XT4 and XT5. Please discard PIE0582.
Brand: Model: Model Year: VIN: Engine: Transmission:
from to from to
Cadillac XT4 2020 2021 – – – –
XT5
XT6
Involved Region or Country North America
Additional Options (RPOs) Equipped with HEAD UP DISPLAY-WINDSHIELD (RPO UV6)
Condition Important: If the customer did not bring their vehicle in for this concern, DO NOT proceed with this EI.
Some customers may comment on the Head Up Display (HUD) is blank. They may also comment that the HUD
could become operational by changing the HUD dimming level or by an ignition cycle.
Technician may find DTC U1518 set.
Cause GM Engineering is attempting to determine the root cause of the above condition. Engineering has a need to
gather information on vehicles PRIOR to repair that may exhibit this condition. As a result, this information will be
used to “root cause” the customer’s concern and develop/validate a field fix.
Correction
If you encounter a vehicle with the above concern, perform the following steps and contact the engineer listed below with your findings.
Verify that DTC U1518 – Loss of communication with Head Up Display is stored in the instrument cluster.
• If the DTC is stored current or history, proceed with this Engineering Investigation PI, gather as much information as possible from the questions below, and
contact the GM Engineer to discuss next steps.
• If the DTC is not stored, then this Engineering Investigation DOES NOT apply. Refer to Head-Up Display Malfunction in SI for diagnostic procedures.
Please discuss the following six questions with the customer to gain details from their experience:
1. When did the condition occur? Example: at startup, after driving, note the driving conditions such as weather, road conditions, day/night, city/highway, etc.
2. Has the blank HUD condition occurred more than once?
2.1. Can the customer reproduce the condition with any specific actions or sequence of events?
3. What was customer doing when the condition occurred? Example: Use of steering wheel controls, HUD controls, adjusting or scrolling any Cluster Settings,
changing Drive modes (normal/sport)?
4. Does the blank HUD condition recover? If so, how is it recovered? Example: ignition cycle or change HUD dimming level.
5. Did customer notice if the instrument cluster went blank, or acted up in other ways before the HUD went blank?
6. Were the steering wheel controls exhibiting any issues around the same time the blank HUD condition occurred?
The remaining questions are for the dealer technician to answer PRIOR to contacting the GM Engineer.
1. With the vehicle running, is the condition of blank/no HUD image and a current DTC U1518 present or reproducible?
2. Record all DTCs, where they are stored, and their status (Current/History).
3. Contact the GM Engineer to provide answers to the questions above.
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Contact Information
Please include the following information if leaving a message:
– Technician name
– Dealer name and phone number
– Complete VIN and repair order (R.O) number
On the repair order, document the date and time the call was placed (even if the engineer was not reached).
If engineering is unable to return the call within one hour, proceed with diagnosis and repair based on information found in SI.
Warranty Information
If engineer was contacted or required information was provided, use:
Labor Operation Description Labor Time
3487118* Engineering Information – Head Up Display (HUD) Blank, DTC U1518 Set 0.3 hr
* This is a unique labor operation for bulletin use only.
Version 2
Modified Released August 27, 2020
Revised November 04, 2020 – Revised to add 2020-2021 XT4 and XT5.
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The Contact Information has been redacted.

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