# Service bulletin T020 \- PB

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11016468
- Published by NHTSA: 2025\-04\-04
- Manufacturer's number: T020 \- PB
- Manufacturer's date: 2025\-03\-20
- Campaign id or software version: T020 \- PB
- NHTSA component: POWER TRAIN

## NHTSA's summary

Fix\-As\-Fail Certain Model 535, 536, 537, and 548 chassis equipped with a PACCAR TX\-8 transmission received transmission software with an incorrect variable. This software issue may cause DTC 521215\-2 to set, the Transmission Dash Light to Illuminate, and shifting to be restricted. A software update is now available to fix the issue. Fix\-as\-Fail start date: 03/19/2025.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11016468-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11016468-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Transmission and driveline

## Vehicles listed

- 2024 to 2025 PETERBILT 535
- 2024 to 2026 PETERBILT 536
- 2024 to 2026 PETERBILT 537
- 2024 to 2026 PETERBILT 548

## Recalls for the same vehicles and component

- [2025018](/recalls/tc/2025018.md), 2025-01-16: Powertrain
- [24V903000](/recalls/nhtsa/24V903000.md), 2024-12-02: POWER TRAIN:AXLE HUBS
- [24V190000](/recalls/nhtsa/24V190000.md), 2024-03-20: POWER TRAIN:AUTOMATIC TRANSMISSION:LEVER AND LINKAGE:COLUMN SHIFT
- [2023437](/recalls/tc/2023437.md), 2023-08-04: Powertrain
- [23V504000](/recalls/nhtsa/23V504000.md), 2023-07-21: POWER TRAIN:DRIVELINE

## Other bulletins for the same vehicles and component

- [T017](/bulletins/11037625.md), 2026-10-01, Service bulletin: UNKNOWN OR OTHER; POWER TRAIN. Information has been added to identify that ECAT incorrectly identifies PS386 as the correct transmission oil for TX\-8 transmission on certain vehicles.\[
- [T024](/bulletins/11033925.md), 2026-06-17, Service bulletin: POWER TRAIN. "KW \& PB: New software is available for download. The DAVIE4 cache must be cleared before attempting to reprogram a chassis that is experiencing problems to ensure the latest version of software is installed. Follow all steps in the attached procedures before submitting a TCS case."
- [T\-024](/bulletins/11033923.md), 2026-06-17, Service bulletin: POWER TRAIN. The repair procedure has been updated to include diagnostic steps.
- [T024](/bulletins/11033379.md), 2026-06-03, Service bulletin: POWER TRAIN. KW: A Transmission Control Module \(TCM\) software update is now available for certain T280, T380, T480, T680, T880, and W990 chassis with PACCAR TX\-12 and TX\-18 transmissions, TCM software version R5.5 or later and an AT5 controller, where the TASPS fails. PB: A Transmission Control Module \(TCM\) software update is now available for certain Model 537, 548, 567, 579, and 589 chassis with PACCAR TX\-12 and TX\-18 transmissions, TCM software version R5.5 or later and an AT5 controller, where the TASPS fails.
- [24PBE](/bulletins/11026415.md), 2025-12-05, Service campaign: ELECTRICAL SYSTEM; POWER TRAIN. The right\-hand shift stalk may have an improper wire harness terminal crimp within the wire harness connector. Loss of communication between the right\-hand shift stalk and the vehicle may result in the vehicle being disabled after it comes to a stop, thereby increasing the risk of crash or injury. A warning will appear on the dash display when communication is lost, including transmission or engine warnings, “\!” next to DNR/DNRP indicator, “\-“ in the DNR/DNRP indicator, and/or chimes, depending upon whether you are operating a diesel/gas or battery electric vehicle.
- [24PBJ](/bulletins/11021490.md), 2025-08-05, Service bulletin: POWER TRAIN; SUSPENSION. "Safety Recall Parts and repair procedures are now available. Certain Meritor 10\-16K and 18\-23K Front Steer Drive Axles may have insufficient wheel bearing grease. Insufficient lubrication in the wheel bearing may cause the wheel hub to overheat and become damaged, which may increase the risk of a crash or thermal event . The driver may hear noise, excessive steering play, and/or smoke from the front wheel.
- [E307](/bulletins/10254171.md), 2024-05-04, Service bulletin: POWER TRAIN; ENGINE AND ENGINE COOLING. CARB Emission s Manufacturer Warranty term and/or kilometers conversion displayed in certain EMY 2022\-2023 PX\-7 or PX\-9 Operator’s Manuals are incorrect.
- [24PBE](/bulletins/10252585.md), 2024-04-03, Service bulletin: POWER TRAIN; ELECTRICAL SYSTEM. INTERIM Safety Recall Parts are not currently available for this safety recall. This bulletin will be updated once repair parts are available. The right\-hand shift stalk may have an improper wire harness terminal crimp within the wire harness connector. Loss of communication between the right\-hand shift stalk and the transmission may result in the vehicle becoming disabled after it comes to a stop thereby increasing the risk of crash or injury. A transmission fault will appear on the dash display if communication is lost.
- [23PBE](/bulletins/10241496.md), 2023-09-01, Service bulletin: POWER TRAIN. Safety Recall Certain vehicles built with TX\-8 transmissions with flange mounted yokes may not have a locking feature installed on fastener threads. This may allow the driveline fasteners to become loose, increasing the risk of a crash.

JSON: [/v1/bulletins/11016468](/v1/bulletins/11016468)

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