22NA015

Bulletin No.:
Service Bulletin
Date:
22-NA-015
February, 2022
INFORMATION
Subject:
Diagnostic Tip on Shake and/or Shudder During Light Throttle Acceleration Between
25 and 80 MPH (40 and 128 KM/H) at Steady Speed
Brand:
Model:
Cadillac
to
Escalade Models
2021
2022
Silverado 1500
2020
2021
2022
2022
2021
2022
Sierra 1500
2020
2021
Sierra 1500
(Limited, RPO J21,
12th VIN Digit = 4
or less)
2022
2022
2021
2022
Silverado 1500
(LTD, RPO J21, 12th
VIN Digit = 4 or less)
Chevrolet
Silverado 1500
(RPO J22, 12th VIN
Digit = 5 or greater)
Suburban
Tahoe
GMC
Model Year:
from
VIN:
from
to
Engine:
Transmission:
L84, L87
MQB, MQC, MHS
Sierra 1500
(RPO J22, 12th VIN
Digit = 5 or greater)
Yukon Models
Involved Region or Country
North America, Australia, New Zealand
Condition
Some customers may comment of a shudder, shake, vibration from approximately 25 –
50 mph (40-80 km/h) while under steady to lightly accelerating throttle.
Cause
This condition may be caused by various transmission and engine concerns. See the
Diagnostic Tips below.
– Check for Transmission and Engine related DTC’s. Resolve any DTC’s before and
reevaluate the vehicle before proceeding.
Correction
Diagnostic Tips Test Drive
The customers vehicle should be test driven in an effort to duplicate the condition. Details
of vehicle speed, driving conditions and throttle input may need to be discussed with the
customer. Some normal shudder, shake, vibration or growl can be expected in low speed,
light throttle applications as the vehicle may be going in and out for Dynamic Fuel
Management (DFM). DFM can be turned off for a test drive by shifting the transmission
into Manual Range “L9”. Driving a like vehicle under the same conditions may help
determine if the vehicle is operating like other vehicles and should be considered
characteristic of design
Copyright 2022 General Motors LLC. All Rights Reserved.
Page 2
February, 2022
Diagnostic Tips Engine Performance
Bulletin No.: 22-NA-015
Diagnostic Tip Engine Related Shudder –
PIP5794B Camshaft Actuator
5975000
1. Engine Speed
2. Engine Torque
3. Vibration Felt after Engine Refuel, Should be in
Reduced Firing Fraction
4. Pedal
5. Turbine Speed
Diagnostic Tip Closed Throttle Shudder – TSB
21-NA-207: 2021 Silverado Sierra 5.3 (L84) 10 Speed
(MQB) only.
The condition is only present at 0% throttle during a
coast event at approximately 15 mph (24 km/h). Note
the engine RPM and torque oscillations at engine refuel
points.
5975002
1. Torque
2. Engine Speed
3. Turbine Speed
4. Pedal
Record a GDS session log and monitor engine speed,
transmission input speed and engine torque. If engine
torque is larger than +- 25 Nm while no gear shift is
active, and throttle is relatively constant the issue most
likely lies within the engine.
Observe the large variation in engine torque while
engine speed and turbine speed follow each other more
closely. Although this feels like shudder to the customer
it is most likely an engine related concern.
Bulletin No.: 22-NA-015
February, 2022
Diagnostic Tips TCC Solenoid – Valve Body
Page 3
3. Turbine Speed
4. TCC Pressure
• Shudder condition is present in Drive “D” but NOT
present in Manual “L9”
• Throttle would typically be less than 10% and
engine torque less than 100 Nm
• TCC slip speed will be 0 or near 0
• TCC pressure command will remain at 100 kPa
The valve body should be replaced.
Diagnostic Tip TCC Shudder – Torque
Converter
5975003
1.
2.
3.
•
Torque
Engine Speed
Turbine Speed
The shudder condition is present both in Drive “D”
or Manual “L9”.
• Typically occurs at less than 15,000 miles
(24,000 km)
• Turbine speed follows engine speed
• Relatively consistent engine torque. <+- 25 Nm
Engine torque remains relatively flat while engine
speed rises and falls. The valve body should be
replaced.
Diagnostic Tip TCC Solenoid (Drift) –
Valve Body
5975005
1. Torque
2. Engine Speed
5975007
1.
2.
3.
4.
•
•
•
Torque
Engine Speed
Turbine Speed
Pedal
TCC pressure control is steady
TCC slip is elevated
Engine RPM will increase at the shudder point
while turbine speed remains steady
• Engine torque remains relatively steady during the
shudder event
• Throttle angle remains steady during the shudder
event
The torque converter should be replaced.
Page 4
February, 2022
Version
1
Modified
Released January 27, 2022
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.
Bulletin No.: 22-NA-015
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION