21NA283

Bulletin No.:
Service Bulletin
Date:
21-NA-283
February, 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
2022
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 the 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
February, 2022
Bulletin No.: 21-NA-283
Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
8020652
Description
Labor Time
Front Hydraulic Suspension
Bleeding
Use
Published
Labor
Operation
Time
Version
2
Modified
Released December 06, 2021
January 28, 2022 – Added Suspension Pump Noise to Subject and Condition section and
added Additional SI Keywords.
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.
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