TSB: MACK ANTHEM (AN), CHU, CXU, GRANITE (GR), GRANITE (GU), GU, MRU, PINNACLE (CHU), PINNACLE (CXU), PINNACLE (PI), TERRAPRO (TE), VAH, VHD, VNL, VNM (2018–2020)

Bulletin K93394430 — July 1, 2019

Bulletin Details

Bulletin IDK93394430
ManufacturerMACK
ModelsANTHEM (AN), CHU, CXU, GRANITE (GR), GRANITE (GU), GU, MRU, PINNACLE (CHU), PINNACLE (CXU), PINNACLE (PI), TERRAPRO (TE), VAH, VHD, VNL, VNM
Model Years2018–2020
Date IssuedJuly 1, 2019
Date Added to NHTSAJuly 15, 2019
ComponentENGINE (PWS)
Vehicles Affected46 combinations

What is a TSB?

A Technical Service Bulletin is a document issued by the vehicle manufacturer to inform dealership technicians about a known issue and the recommended repair procedure. TSBs are not mandatory recalls — they serve as repair guidance for common problems.

If your vehicle has this issue, bring this bulletin ID to your dealer. If under warranty, the repair should be covered at no cost.

Summary

Engine Brake - Diagnostic Trouble Code (DTC) P1021-11 Volvo Compression Brake (VCB) Control Circuit Short To Ground - US17+OBD16 Through US17+OBD19 Emissions, Model Years 2018 To 2020

Affected Vehicles

MakeModelYearComponent
MACK ANTHEM (AN) 2020 110000 ELECTRICAL SYSTEM
MACK GRANITE (GR) 2020 110000 ELECTRICAL SYSTEM
MACK GRANITE (GU) 2020 110000 ELECTRICAL SYSTEM
MACK PINNACLE (CHU) 2020 110000 ELECTRICAL SYSTEM
MACK PINNACLE (CXU) 2020 110000 ELECTRICAL SYSTEM
MACK PINNACLE (PI) 2020 110000 ELECTRICAL SYSTEM
MACK TERRAPRO (TE) 2020 110000 ELECTRICAL SYSTEM
VOLVO VAH 2020 060000 ENGINE (PWS)
VOLVO VAH 2020 110000 ELECTRICAL SYSTEM
VOLVO VHD 2020 060000 ENGINE (PWS)
VOLVO VHD 2020 110000 ELECTRICAL SYSTEM
VOLVO VNL 2020 110000 ELECTRICAL SYSTEM
VOLVO VNL 2020 060000 ENGINE (PWS)
VOLVO VNM 2020 110000 ELECTRICAL SYSTEM
VOLVO VNM 2020 060000 ENGINE (PWS)
MACK ANTHEM (AN) 2019 110000 ELECTRICAL SYSTEM
MACK GRANITE (GR) 2019 110000 ELECTRICAL SYSTEM
MACK GRANITE (GU) 2019 110000 ELECTRICAL SYSTEM
MACK PINNACLE (CHU) 2019 110000 ELECTRICAL SYSTEM
MACK PINNACLE (CXU) 2019 110000 ELECTRICAL SYSTEM
MACK PINNACLE (PI) 2019 110000 ELECTRICAL SYSTEM
MACK TERRAPRO (TE) 2019 110000 ELECTRICAL SYSTEM
VOLVO VAH 2019 060000 ENGINE (PWS)
VOLVO VAH 2019 110000 ELECTRICAL SYSTEM
VOLVO VHD 2019 060000 ENGINE (PWS)
VOLVO VHD 2019 110000 ELECTRICAL SYSTEM
VOLVO VNL 2019 110000 ELECTRICAL SYSTEM
VOLVO VNL 2019 060000 ENGINE (PWS)
VOLVO VNM 2019 060000 ENGINE (PWS)
VOLVO VNM 2019 110000 ELECTRICAL SYSTEM
MACK ANTHEM (AN) 2018 110000 ELECTRICAL SYSTEM
MACK CHU 2018 110000 ELECTRICAL SYSTEM
MACK CXU 2018 110000 ELECTRICAL SYSTEM
MACK GRANITE (GR) 2018 110000 ELECTRICAL SYSTEM
MACK GU 2018 110000 ELECTRICAL SYSTEM
MACK MRU 2018 110000 ELECTRICAL SYSTEM
MACK PINNACLE (PI) 2018 110000 ELECTRICAL SYSTEM
MACK TERRAPRO (TE) 2018 110000 ELECTRICAL SYSTEM
VOLVO VAH 2018 060000 ENGINE (PWS)
VOLVO VAH 2018 110000 ELECTRICAL SYSTEM
VOLVO VHD 2018 060000 ENGINE (PWS)
VOLVO VHD 2018 110000 ELECTRICAL SYSTEM
VOLVO VNL 2018 060000 ENGINE (PWS)
VOLVO VNL 2018 110000 ELECTRICAL SYSTEM
VOLVO VNM 2018 060000 ENGINE (PWS)
VOLVO VNM 2018 110000 ELECTRICAL SYSTEM

Related MACK Recalls

CampaignModelYearComponentSummary
ANTHEM AN (4) 2026 SERVICE BRAKES, AIR:ANTILOCK:CONTROL ... Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-...
ANTHEM AN (4) 2027 SERVICE BRAKES, AIR:ANTILOCK:CONTROL ... Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-...
PIONEER PR (4) 2025 SERVICE BRAKES, AIR:ANTILOCK:CONTROL ... Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-...
PIONEER PR (4) 2026 SERVICE BRAKES, AIR:ANTILOCK:CONTROL ... Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-...
PIONEER PR (4) 2027 SERVICE BRAKES, AIR:ANTILOCK:CONTROL ... Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-...

What Should You Do?

If your vehicle is affected by this TSB, contact your authorized MACK dealer. Bring this bulletin ID (K93394430) when you visit. If under warranty, the repair should be free. If your warranty has expired, ask about goodwill coverage — manufacturers sometimes cover TSB-related repairs beyond the warranty period.

Frequently Asked Questions

A recall is a mandatory safety fix — the manufacturer must repair every affected vehicle for free. A TSB is an advisory document that describes a known issue and the recommended fix, but repairs are not required. However, some TSBs eventually lead to recalls if the issue poses a safety risk. TSBs are generally issued for quality or performance problems, while recalls address safety defects.

If your vehicle is still under the manufacturer's warranty, TSB-related repairs are typically covered at no cost. If your warranty has expired, you can ask the dealer about goodwill or customer assistance programs. Many manufacturers will cover or partially cover repairs for well-known issues, especially if the TSB was issued recently or affects a large number of vehicles.

Check the make, model, and model year listed above against your vehicle. If they match, this bulletin likely applies. However, TSBs may only affect vehicles with specific production dates, VIN ranges, or configurations. Your dealer can confirm by entering your VIN into their service system, which will show all applicable TSBs and recalls.

This data comes from the National Highway Traffic Safety Administration (NHTSA). Manufacturers are required to submit copies of all communications (including TSBs) sent to their dealers to NHTSA. The agency makes this data publicly available as part of its vehicle safety monitoring program.