22-NA-015
Service Bulletin Details
Public Details for: 22-NA-015
This informational bulletin provides graphs to help identify possible issues that may cause shaking and shudders and what may be the cause of said issue.
Models from 2022
Models from 2021
Models from 2020
2020 CHEVROLET SILVERADO 1500 |
2020 GMC SIERRA 1500 |
Bulletin No.: Service Bulletin Date: 22-NA-015 March, 2022 INFORMATION Subject: Diagnostic Tips on GDS Graphing after Road-Test, for Shake and/or Shudder During Steady and/or Light Throttle Acceleration Between 25 and 50 MPH (40 and 80 KM/H) at Steady Speed, and Decel at approximately 15 MPH (24 KM/H). 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, Europe, Uzbekistan, Middle East, Israel, Argentina (Mercosur), Brazil (Mercosur), Bolivia (West), Chile (West), Colombia (West), Ecuador (West), Paraguay (West), Peru (West), Uruguay (West) 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 March, 2022 Diagnostic Tips Engine Performance ⇒ Diagnostic Tip Related Shutter: 21–NA-207 5975000 1. Engine Speed 2. Engine Torque 3. Vibration Felt after Engine Refuel, Should be in Reduced Firing Fraction 4. Pedal 5. Transmission Input Shaft Speed (ISS) 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. Bulletin No.: 22-NA-015 Diagnostic Tip Engine Related Shudder – PIP5794B Camshaft Actuator 5975002 1. Torque 2. Engine Speed 3. Transmission ISS 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 Transmission ISS 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 March, 2022 Diagnostic Tips TCC Solenoid – Valve Body Page 3 1. 2. 3. 4. • Torque Engine Speed Transmission ISS 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 Transmission ISS The shudder condition is present both in Drive “D” or Manual “L9”. • Typically occurs at less than 15,000 miles (24,000 km) • Transmission ISS 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. 5975007 Diagnostic Tip TCC Solenoid (Drift) – Valve Body 1. 2. 3. 4. • • • Torque Engine Speed Transmission ISS Pedal TCC pressure control is steady TCC slip is elevated Engine RPM will increase at the shudder point while Transmission ISS 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. 5975005 Page 4 March, 2022 Bulletin No.: 22-NA-015 Version 2 Modified Released January 27, 2022 Revised March 21, 2022 - Revised Subject, Added Additional Countries, Change Turbine Speed to Transmission Input Shaft Speed. 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 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