Service Bulletin

Bulletin No.:

20-NA-113

Date:

June, 2020

TECHNICAL
Subject:

Action Required Steering Assist is Reduced Drive with Care Or Service Power Steering
Message And Or Current Power Steering Control Module DTCs
This bulletin replaces PIT5593B. Please discard all copies of PIT5593B.

Brand:

Model:

Model Year:
from

to

VIN:
from

to

Engine:

Transmission:

4.3L RPO LV3 /
5.3L RPO L83 /
6.2L RPO L86

All

Silverado 1500

2017-2018

SOP

Plant Code Z*:
9/12/2017,
Plant Code F*:
9/13/2017,
Plant Code G*:
9/15/2017

Suburban

2017-2018

SOP

Plant Code R*:
9/12/2017

All

All

Tahoe

2017-2018

SOP

Plant Code R*:
9/12/2017

All

All

4.3L RPO LV3 /
5.3L RPO L83 /
6.2L RPO L86

All

All

All

Chevrolet

Sierra 1500

2017-2018

SOP

Plant Code Z*:
9/12/2017,
Plant Code F*:
9/13/2017,
Plant Code G*:
9/15/2017

Yukon

2017-2018

SOP

Plant Code R*:
9/12/2017

GMC

*For Plant Code See 11th Position of VIN

Copyright 2020 General Motors LLC. All Rights Reserved.

Page 2

June, 2020

Involved Region or Country

North America

Additional Options (RPO)

Without RPO UHX Lane Keep Assist
Without RPO NV8 Variable Assist Power Steering

Bulletin No.: 20-NA-113

Note: This bulletin does NOT apply to 2500/3500 HD Trucks.

Condition

Some customers may comment that every time the vehicle is started an "Action Required
Steering Assist is Reduced Drive with Care" Or "Service Power Steering" Message is
displayed. In most cases, there will be no steering related issues and if the message is
dismissed it will remain off the entire ignition cycle.
When checking for DTC's the Power Steering Control Module (PSCM) will have current
DTC's set. The most common DTC's which may set are:
• C0176
• C0544
• U0100
• U0101
• U0140
• U0121
• U0073
• U0126
• U0428 71
• U0415
• U0401

Cause

A Power Steering Control Module (PSCM) calibration error has been found, which does
not allow its DTC's to transition to history and they stay current. Even when the issue that
caused the DTC's to set originally, is no longer present, the PSCM will retain the DTC(s)
as current.

Correction

This calibration error can mislead technicians, because the initial steps in normal strategy
based diagnosis is to verify the customer complaint and follow current DTC's. To help
avoid misdiagnosis, follow the steps below:
1. Check and record all DTC's in all modules.
2. Clear all DTC's. If all DTC's can be cleared, go to step 3. If DTC's will not clear, the
vehicle is experiencing a current fault, which will need to be diagnosed and repaired
before continuing to step 3.
3. Reprogram the PSCM with the latest calibrations currently available in TIS2WEB,
and clear any DTC's which may have set during the programming event.
4. Let the vehicle go to sleep, then restart the engine and check for DTC's. If any
DTC's reset, perform normal diagnosis and repair as necessary.
5. If no DTC's reset, it will be necessary to look at all recorded DTC's in step 1 to help
determine the original root cause. See additional information/example below.

Bulletin No.: 20-NA-113

June, 2020

Service Procedure
Additional Information and Example:
Remember, this PSCM calibration error only causes the
DTC's to stay current, which then causes the PSCM
messages to appear at each start up.
Afterreprogramming the PSCM with the latest
calibrations, the original root cause of the DTC's may
still need to be addressed. See example below.
– Customer brings the vehicle in for an "Action
Required Steering Assist is Reduced Drive with
Care" message that is displayed each ignition cycle.
See DIC message below.

– When performing normal strategy based diagnosis, a
technician would start the vehicle and verify the
customer's complaint of the "Action Required
Steering Assist is Reduced Drive with Care"
message, he or she would find current DTC's set in
the PSCM. Finding these current codes may lead a
technician down the wrong path, which is why it is
important to follow the steps listed above.
– In this example, all the DTC's cleared out and the
PSCM was reprogrammed with the latest calibrations
available in TIS2WEB.
– Looking back at all the DTC's recorded, the EBCM
had two wheel speed sensor DTC's set: C0035 and
C0040. These two DTC's would be the original root
cause and would need to be addressed.
– If the vehicle was returned to the customer without
addressing the EBCM DTC's, he or she may return
for service but would be a different complaint, such
as, an intermittent ABS MIL and/or Service
Stabilitrak message. The same DTC's will be found
in the PSCM and EBCM, but now the new PSCM
calibration will allow the DTC's to transition to history
and there will no longer be a PSCM DIC message
displayed at each ignition cycle.
Caution: Before downloading the update files, be sure
the computer is connected to the internet through a
network cable (hardwired). DO NOT DOWNLOAD or
install the files wirelessly. If there is an interruption
during programming, programming failure or control
module damage may occur.
Note: Carefully read and follow the instructions below.
•

4889886

– When checking for DTC's the following codes are
found: See also the GDS2 screen print of the DTC's
below.
PSCM has two current DTC's U0415 and U0401
EBCM has two history DTC's C0035 and C0045

•

•

•

4889885

Page 3

Ensure the programming tool is equipped with the
latest software and is securely connected to the
data link connector. If there is an interruption
during programming, programming failure or
control module damage may occur.
Stable battery voltage is critical during
programming. Any fluctuation, spiking, over
voltage or loss of voltage will interrupt
programming. Install a GM Authorized
Programming Support Tool to maintain system
voltage. Refer to www.gmdesolutions.com for
further information. If not available, connect a fully
charged 12 V jumper or booster pack
disconnected from the AC voltage supply. DO
NOT connect a battery charger.
Turn OFF or disable systems that may put a load
on the vehicles battery such as; interior lights,
exterior lights (including daytime running lights),
HVAC, radio, etc.
Clear DTCs after programming is complete.
Clearing powertrain DTCs will set the Inspection/
Maintenance (I/M) system status indicators to NO.

Page 4

June, 2020

Bulletin No.: 20-NA-113

5431207

Important: TIS2WEB screen shown. Techline Connect
screen is simlar and will be included soon.
Important: If the Same Calibration/Software Warning
is noted on the SPS screen, select OK and follow
screen instructions. After a successful programming
event, the WCC is located in the Service Programming

System dialogue box of the SPS Summary screen. No
further action is required. Refer to the Warranty section
of the bulletin.
1. Reprogram the Power Steering Control Module.
Refer to K43 Power Steering Control Module:
Programming and Setup in SI.

Bulletin No.: 20-NA-113

June, 2020

Page 5

5431209

Important: TIS2WEB screen shown. Techline Connect
screen is simlar and will be included soon.
Important: To avoid warranty transaction rejections,
you MUST record the warranty claim code provided on
the SPS Warranty Claim Code (WCC) screen on the
job card. Refer to callout 1 above for the location of the
WCC on the SPS screen
2. Record SPS Warranty Claim Code on job card for
warranty transaction submission.

Page 6

June, 2020

Bulletin No.: 20-NA-113

Labor Operation

Description

Labor Time

*2810625

Power Steering Control Module Reprogramming with SPS

Use Published Labor
Operation Time

Warranty Information
For vehicles repaired under warranty, use:

Important: *To avoid warranty transaction rejections, carefully read and follow the instructions below:
• The SPS Warranty Claim Code must be accurately entered in the “SPS Warranty Claim Code” field of the transaction.
• When more than one Warranty Claim Code is generated for a programming event, it is required to document all Warranty
Claim Codes in the “Correction” field on the job card. Dealers must also enter one of the codes in the “SPS Warranty Claim
Code” field of the transaction, otherwise the transaction will reject. It is best practice to enter the FINAL code provided
by SPS.

Warranty Claim Code Information Retrieval
If the SPS Warranty Claim Code was not recorded on
the Job Card, the code can be retrieved in the SPS
system as follows:
1. Open TIS on the computer used to program the
vehicle.
2. Select and start SPS.
3. Select Settings.
4. Select the Warranty Claim Code tab.
The VIN, Warranty Claim Code and Date/Time will be
listed on a roster of recent programming events. If the
code is retrievable, dealers should resubmit the
transaction making sure to include the code in the SPS
Warranty Claim Code field.

Additional SI Keywords
C0176 C0475 c0544 c0545 C056D C0045 C0050 U0100 U0101 U0140 U0121 U0126 U0131
Version

1

Modified

Released May 28, 2020

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.

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