Chevrolet, GMC and 2 others preliminary evaluation PE23016
6L90 Transmission Failure. NHTSA’s Office of Defects Investigation opened this preliminary evaluation about the valves/valve body on 20 model years (2016–2022). Opened Sep 27, 2023, closed Jan 10, 2025 after 15 months without a recall. closed
What NHTSA says
Source: Office of Defects Investigation, as filedThe Office of Defects Investigation (ODI) opened this Preliminary Evaluation (PE) after receiving one Vehicle Owner Questionnaire (VOQ) complaint related to four school buses built on General Motors (GM) van chassis. The VOQ alleged transmission failure resulting in a loss of all forward gear. In ODI's pre-investigative discussions with GM, ODI learned that valve body separator plates had been machined out of tolerance during production periods between October 2016 to April 2017 and February 2021 to April 2021. This out of tolerance machining may create excessive wear to the valve body check balls, possibly resulting in an inability to engage drive or reverse. The potential loss of drivability only begins when shifting from a park or neutral transmission selection and does not occur during a functional drive cycle. The average failure mileage of vehicles which experienced this condition is within warranty and related claims or complaints did not include any accidents, injuries, or fatalities. After discussions with GM, Technical Service Bulletin (TSB) 23-NA-142 (NHTSA ID number 10243753) was released in September 2023. This technical service bulletin provides a procedure for technicians to replace the forward check ball and separator plate if found to be the cause of a customer's concern. During the course of the investigation, GM also released a Customer Satisfaction Program (CSP) N232428780 (NHTSA ID 10253316) in February 2024, to notify school bus and ambulance fleets of the concern and to proactively mitigate the risk in these essential-operation vehicles. Recently, ODI contacted multiple school bus fleets, verifying that there have not been any stranded buses mid-route from this condition. Additionally, ODI has not received any additional VOQ complaints since the opening of this investigation. Based on the available information, including GM's TSB and CSP, this PE is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The Agency reserves the right to take additional action if warranted by future circumstances. To review the ODI report cited in the Closing Resume ODI Report Identification Numbers document, go to NHTSA.gov.
A Preliminary Evaluation is the first formal stage: NHTSA has decided the complaints and other information it screened are worth a closer look, and asks the manufacturer for its own data on the condition. The summary is the agency’s own text from its investigation file, unedited; the resumes carrying the full reasoning are linked below.
The paperwork NHTSA filed
Source: every document on this action, at nhtsa.gov- Opening resume — ODI’s own summary of why it opened this — the subject, what prompted it, and the vehicles in scope.
- Closing resume — ODI’s own summary of why it closed this, and what it concluded.
| Document | Code | Filed | At NHTSA |
|---|---|---|---|
| Opening resume | INOA | 2023 | |
| Closing resume | INCLA | 2023 | |
| Information request to the manufacturer | INIM | 2023 | |
| Manufacturer's response — data | INRD | 2023 | 10 files 12345678910 |
| Manufacturer's response — full submission | INRL | 2023 | 3 files 123 |
| Filed document | INOV | 2023 | |
| Filed document | INCV | 2023 |
These are NHTSA’s own files, served from the agency’s site — the resumes are what ODI wrote when it opened and closed the action, and the rest is the correspondence behind them, including what the manufacturer sent when the agency asked. They are linked, not copied: where a document names the people who wrote in, that redaction is the agency’s to make and its copy is the one you should read.
What owners had already reported
Source: complaints on file the day it openedWhen NHTSA opened this on Sep 27, 2023, owners had filed 27 complaints with the agency about the model years above, of which 5 named the power train NHTSA went on to investigate. Owner complaints are the agency’s main early signal: ODI screens them, and a Preliminary Evaluation is usually where a pattern in them ends up.
This is what the complaint file held on that date, not a claim about which reports prompted the investigation — NHTSA’s complaint records carry no investigation number, so nobody can make that link from the data alone. The opening resume linked above names the reports ODI itself cited. Complaint records on this site begin with 2016.
What this means for an owner
Source: and what happens nextAn investigation is not a finding that a defect exists, and it puts no duty on anyone. NHTSA opens a Preliminary Evaluation when complaints and other reports suggest a condition worth asking the manufacturer about; it upgrades to an Engineering Analysis when the answers warrant testing; it closes either when it recommends a recall, when the manufacturer recalls on its own, or when no defect trend is found. The agency’s own goals are about four months for a petition, eight for a Preliminary Evaluation or a Recall Query and eighteen for an Engineering Analysis; many run longer.
This one closed without a recall. That means NHTSA found no defect trend it chose to act on at the time, or the manufacturer addressed the condition another way (a service campaign or a bulletin, which have their own pages). A closed file can be reopened if new reports arrive.
Model years it names
Source: as NHTSA filed themAlso named on model years this site has no page for: 2016 Micro Bird MB II School Bus; 2017 Micro Bird MB II School Bus; 2021 Micro Bird MB II School Bus; 2022 Micro Bird MB II School Bus; 2018 Micro Bird MB II Transit Bus; 2016 Thomas Built Buses Minotour; 2017 Thomas Built Buses Minotour; 2018 Thomas Built Buses Minotour; 2021 Thomas Built Buses Minotour; 2022 Thomas Built Buses Minotour.
A vehicle page’s investigation list carries the same action; a name here is the scope NHTSA opened, not a list of affected VINs.
Common questions
Source: NHTSA Office of Defects InvestigationIs PE23016 a recall?
No. A preliminary evaluation is NHTSA asking questions, not a recall. A safety recall carries an NHTSA campaign number and a duty to repair for free; this one closed without one. Whether one particular vehicle has an open recall is a VIN question at nhtsa.gov/recalls.
Is PE23016 still open?
No. It closed on Jan 10, 2025 without a recall.
Which vehicles does PE23016 cover?
NHTSA opened it on 20 model years: 2022 Chevrolet Express, 2021 Chevrolet Express, 2018 Chevrolet Express, 2017 Chevrolet Express, 2016 Chevrolet Express, 2022 GMC Savana and more. That is the scope of the inquiry, not a list of affected vehicles; a recall, if one follows, defines its own population by VIN.