Rear View Camera Image Flickers When Brake Lamps or Turn Signals are On – 2019-2020 Chevrolet Silverado & GMC Sierra

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Service Bulletin Bulletin No.: 20-NA-188
Date: November, 2021
TECHNICAL
Subject: Rear View Camera Image Flickers When Brake Lamps or Turn Signals are On
This Bulletin replaces PIT5639, please discard PIT5639.
Brand: Model:
Model Year: VIN: Engine: Transmission:
from to from to
Chevrolet
Silverado 1500
(New Model) 2019 2019 SOP July
15, 2019
Silverado
2500/3500 HD
2020 2020
GMC
Sierra 1500
(New Model)
2019 2019 SOP July
15, 2019
Sierra
2500/3500 HD
2020 2020
Involved Region or Country North America
Additional Options (RPOs) Equipped with RADIO-INFOTAINMENT SYSTEM – 3.X LOW HMI, MIDLEVEL
CONNECTIVITY 3.X (RPO IOR)
Condition
Some customers may comment on a slight flickering or distortion in the rear view camera
image (while in reverse or in Camera view mode) when the brake lights, turn signals, or
hazard flashers are on.
Cause The cause of the condition may be due to voltage induced in camera image feed wires
from brake light circuits distorting the image.
Correction Re-string the camera image feed +/- with a twisted pair utilizing a “drain” (High Speed
Data Cable Assembly) that shields the circuits from induced voltage.
Service Procedure
Using the illustration below, restring the camera image
feed [+/-] with a High Speed Data Cable Assembly that
shields the circuits from induced voltage.
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Restring the camera image feed [+/-] from the A11
Radio to X926 harness (1).
Wrap the entire length of the new data cable (P/N
84991086) with KENT AUTOMOTIVE anti-abrasion
tape (P/N 1089482) before routing the cable along the
vehicle.
For proper wire repair refer to Wire to Wire Repair in SI
For SIlverado 1500 or Sierra 1500 follow the step by
step procedure below, for Silverado 2500HD/3500HD
or Sierra 2500HD/3500HD jump to the HD truck
section.
Silverado 1500 and Sierra 1500:
1. Lift and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.
2. Remove passenger side tire and wheel and
passenger wheelhouse liner. Refer to Tire and
Wheel Removal and Installation, and Front
Wheelhouse Liner Replacement in SI.
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3. Locate the body harness (1) to A11 Radio. Located
under the vehicle, in right front wheel well, near the
frame rail.
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4. Cut an opening into a small entry port (1) of the
cowl into the vehicle and feed one end of the data
cable into the vehicle.
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5. From the entry point (1) run the data cable
rearward alongside the wire harness, securing with
zipties (2) snug to the harness to prevent
movement.
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Continue running data cable rearward alongside
the wire harness (1) and (2).
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6. Then continue down along vehicle frame towards
the rear of the vehicle, following along the wire
harness (1) securing the data cable (2).
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Utilizing the harness clips (1) or zipties to secure
the data cable along the harness.
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7. Utilizing wire harness clips or zipties continue
running the data cable (1) to the rear of the vehicle.
Across vehicle frame and over spare tire.
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Locate the X926 Endgate Harness to Chassis
Harness (1) and run the data cable over the spare
tire (2) to the harness.
8. Disconnect the Chassis Harness from the Endgate
Harness. At the back of the Chassis Harness
locate the ground wire (black w/ white stripe), and
Rearview Camera Signal positive [+] (gray w/
yellow stripe) [+] and negative [-] wires (white w/
blue stripe) [-].
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9. Splice in and seal the new ground wire with the
existing connected ground wire at the harness (1).
Then splice and seal positive and negative data
cable wires with the existing wires (2 and 3).
Note: Positive and Negative wires on the data cable do
not specifically have to connect to either color wire but
both wires must be connected to the same color on the
other end.
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10. Cover open wires with abrasion resistant tape and
reconnect the X926 Harness.
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11. Locate and access the A11 Radio module under
the passenger side I/P. Refer to Radio
Replacement in SI.
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Disconnect the gray A11 Radio X2 Connector (1).
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12. Splice in and seal the matching wire color with the
positive (+) and negative (-) data cable (1) and (2).
Do Not connect the ground at the radio, cut away
the ground wire. Reconnect the A11 Radio X2
Connector.
13. Reassemble the A11 radio and passenger side I/P.
Refer to Radio Replacement in SI.
14. Wrap the full length of the data cable with
Anti-Abrasion tape with “D” level protection.
15. Seal the pass-through at the body harness to
prevent water intrusion and reinstall the front
wheelhouse liner and tire and wheel. Refer to Front
Wheelhouse Liner Replacement in SI.
16. Wrap the full length of the data cable with
Anti-Abrasion tape with “D” level protection.
17. Remove the support and lower the vehicle.
18. Verify if the camera image feed is no longer
experiencing distortion condition.
Silverado 2500HD/3500HD and Sierra 2500HD/
3500HD
Note: HD trucks with crew long box the data cable will
be about a half meter short and two will be needed to
complete the circuit.
Note: Wrap the entire length of the new data cable
(P/N 84991086) with KENT AUTOMOTIVE
anti-abrasion tape (P/N 1089482) before routing the
cable along the vehicle.
1. Lift and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.
2. Remove passenger side tire and wheel and
passenger wheelhouse liner. Refer to Tire and
Wheel Removal and Installation, and Front
Wheelhouse Liner Replacement in SI.
3. Locate the body harness (1) to A11 Radio. Located
under the vehicle, in right front wheel well, near the
frame rail.
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4. Cut an opening into a small entry port (1) of the
cowl into the vehicle and feed one end of the data
cable into the vehicle.
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5. From the entry point run the data cable down and
to the main body ground (1) down to the frame rail
and continue rearward securing with zipties.
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6. Then continue down along vehicle frame towards
the rear of the vehicle, following along the frame
(1) securing the data cable utilizing the frame
holes.
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Continue along the frame (1), utilizing the existing
frame holes (2) use zipties to secure the data cable
along the frame to the fuel tank crossmember.
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7. Route on top of the fuel tank crossmember.
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8. Continue down the right-hand side of the frame (1)
adjacent to the existing X926 Endgate Harness to
Chassis Harness.
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9. Disconnect the Chassis Harness from the Endgate
Harness (1). At the back of the Chassis Harness
locate the ground wire (black w/ white stripe), and
Rearview Camera Signal positive [+] and negative
[-] wires (white w/ blue stripe) [-] and (gray w/
yellow stripe) [+].
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10. Splice in ground wire with the existing connected
ground wire (1). Then splice and seal positive and
negative data cable wires with the existing wires (2
and 3).
Note: Positive and Negative wires on the data cable do
not specifically have to connect to either color wire but
both wires must be connected to the same color on the
other end.
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11. Locate and access the A11 Radio module under
the passenger side I/P. Refer to Radio
Replacement in SI.
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Disconnect the gray A11 Radio X2 Connector (1).
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12. Splice in the matching wire color with the positive
(+) and negative (-) data cable (1) and (2).
Reconnect the A11 Radio X2 Connector.
13. Reassemble the A11 radio and passenger side I/P.
Refer to Radio Replacement in SI.
14. Wrap the full length of the data cable with
Anti-Abrasion tape with “D” level protection.
15. Seal the pass-through at the body harness to
prevent water intrusion and reinstall the front
wheelhouse liner and tire and wheel. Refer to Front
Wheelhouse Liner Replacement in SI.
16. Remove the support and lower the vehicle.
17. Verify if the camera image feed is no longer
experiencing distortion condition.
Parts Information
Causal
Part
Description Part
Number
Qty
X CABLE ASMHIGH
SPD DATA
84991086 1
KENT
AUTOMOTIVE
ANTIABRASION
TAPE
1089482 1
Bulletin No.: 20-NA-188 November, 2021 Page 25
Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use the
following labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
Labor Operation Description Labor Time
*3487108 Add High Speed Data Cable Assembly to Analog RVC 1.5 hr
*This is a unique Labor Operation for Bulletin use only.
Version 2
Modified Released April 21, 2021
Revised November 03, 2021 – Clarifying steps for ground wire connection in Service
Procedure.

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