Bulletin No.:

Service Bulletin

Date:

21-NA-283
August, 2022

TECHNICAL
Subject:

Service Front Suspension Lift System Message Displayed on Driver Information
Center (DIC), Noise from Suspension Pump – DTC C103C and/or C103E Symptom
64 Set
This bulletin replaces PIC6434A. Please discard PIC6434A.

Brand:

Model:

Chevrolet

Corvette

Model Year:

VIN:

from

to

from

to

2020

2023

All

All

Engine:

Transmission:

All

All

Involved Region or Country

North America, Europe, Middle East, Japan, Australia/New Zealand

Additional Options (RPO)

Front Suspension Lift System (RPO E60)

Condition

Some customers may comment that they have seen a Service Front Lift System
message displayed on the DIC.
Some customers may also comment on a pump noise.
Technicians may find one or more of the following DTCs set:
• C103C: Left Front Strut Position Sensor Signal
• C103E: Left Front Strut Position Sensor Signal
• Symptom 64: Signal Plausibility Failure (This sub type is used for failures where the
control module detects a single input parameter is operating outside the plausible
range.)

Cause

Note: If there is low mileage on the vehicle or previous service work on this system has
been identified, it is possible that air entrapment in the system may be causing this issue.
This condition may be caused by air entrapment in the lift system.
Attempt to operate the front lift system several times. Determine if the codes will reset or if
the system will raise briefly and then sink back down. If this occurs, that may indicate that
there is indeed air trapped within the front suspension lift system.
Follow the published information in SI for these DTCs, paying particularly close attention
to "Test B" at the end of the flowchart:

Correction

Copyright 2022 General Motors LLC. All Rights Reserved.

⇒ First perform the Prime Front Suspension Pump procedure with the scan tool
five times in an attempt to purge any trapped air bubbles from the system.
⇒ Next, raise and lower the front suspension system through 10 complete
cycles.
If the DTCs reset, perform the Front Hydraulic Suspension Bleed procedure
and re-evaluate the concern.
As a way to double check the system, a technician can measure the
distance between the floor and the lower portion of the vehicle's front fascia.
A correctly operating vehicle should reach a front fascia height of at least 35
mm within 4 seconds of pump operation.

Page 2

August, 2022

Bulletin No.: 21-NA-283

Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict between
the procedures set forth in this bulletin and the
laws that apply to your dealership, you must follow
those applicable laws.

Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation

8020652

Description

Labor Time

Front Hydraulic Suspension
Bleeding

Use
Published
Labor
Operation
Time

Version

3

Modified

Released December 06, 2021
Revised January 28, 2022 – Added Suspension Pump Noise to Subject and Condition
section and added Additional SI Keywords.
Revised August 24, 2022 – Added the 2023 Model Year.

Additional SI Keywords: loud, noisy, pump, assembly,
PDI, rattle

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.

WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION