TruckCodex

393.43 — Brake - relay emergency valve

FMCSA violation code under Vehicle Maintenance. 23,816 events recorded in roadside inspections. Severity weight: 7. Out-of-service eligible.

OOS Eligible
Severity Weight
7
OOS Eligible
Yes
BASIC Category
Vehicle Maintenance
Total Events
23,816
Code
393.43
Code System
FMCSR
BASIC Category
Vehicle Maintenance
OOS Eligible
Yes
Severity Weight
7
Violation Group
BASIC 5
Total Events
23,816
Carriers Cited
19,509

Violation Description

Relay or emergency valve on CMV is defective or malfunctioning.

About This Violation Code

Code 393.43 falls under the Vehicle Maintenance BASIC category in FMCSA's Safety Measurement System (SMS). It carries a severity weight of 7 (scale 1-10, higher = more severe). This violation is Out-of-Service eligible, meaning the driver or vehicle may be placed out of service at roadside when cited.

When this violation is cited during a roadside inspection, it contributes to the carrier's Vehicle Maintenance BASIC score. Carriers with high BASIC percentiles may be prioritized for FMCSA interventions including warning letters, investigations, or compliance reviews.

Regulatory Reference

Federal Motor Carrier Safety Regulations

This violation references 49 CFR 393.43 in the Federal Motor Carrier Safety Regulations.

View on eCFR.gov →FMCSA Violations Search →
Events (all time)
23,816
OOS Events
19,467
OOS Rate
81.7%
Top State (180d)
Texas
298 events

Top Enforcing States

Where 393.43 is most commonly cited (last 180 days)

1.Texas
298
OOS 70.8%
2.North Carolina
266
OOS 100.0%
3.Illinois
150
OOS 99.3%
4.New Mexico
68
OOS 100.0%
5.Kentucky
3
OOS 100.0%

Click a state to see roadside inspection activity, top stations, and carrier profiles in that jurisdiction.

Citation Trend (12 months)

Monthly count of 393.43 citations. Red bars mark months with OOS-triggering citations.

70
Apr
193
May
164
Jun
180
Jul
162
Aug
148
Sep
162
Oct
112
Nov
146
Dec
155
Jan
165
Feb
132
Mar
10
Apr

Most Active Stations

Inspection stations citing 393.43 most often (last 180 days)

1.IH-0030 IN DALLAS CO. (32-64)
34
OOS 97.1%
2.IH-0069 IN FORT BEND CO. (95-1
33
OOS 97.0%
3.8701 IH 30 FRONTAGE
17
OOS 100.0%
4.US77 RIVIERA SCALE
17
OOS 0.0%
5.STATESVILLE WEIGH STATION, I-4
14
OOS 100.0%
6.ANTHONY PORT OF ENTRY
13
OOS 100.0%
7.TW-PGBT IN DALLAS CO. (10-210)
12
OOS 100.0%
8.95
11
OOS 100.0%
9.020 - MARION - I-57 S/B
11
OOS 100.0%
10.74
10
OOS 100.0%

Often Cited Together

Other violations commonly found on the same inspection (last 90 days)

393.9185 co-occurrences396.17C184 co-occurrences392.2RG163 co-occurrences393.48A142 co-occurrences393.95A103 co-occurrences383.23A288 co-occurrences393.95F77 co-occurrences393.9TS54 co-occurrences390.21(a)51 co-occurrences396.3A1BOS45 co-occurrences

Citation patterns suggest related root causes (e.g., HOS violations paired with logbook errors).

Top Carriers Cited

Ranked by frequency • 19,509 carriers total • Page 1 of 781

Top Carriers with 393.43 Violations

Showing 25 of 19,509

fmcsa-violations
Top Carriers with 393.43 Violations
#CarrierUSDOT# Violations
#1MARYLAND TREE EXPERTS330493138
#2BENNETT TRUCK TRANSPORT LLC60038226
#3MASTEC NORTH AMERICA INC77424420
#4UNITED RENTALS NORTH AMERICA INC89974817
#5TRANSPORT INDIANA LLC305779116
#6ACME TRUCK LINE INC5276716
#7RH UNDERGROUND LLC396033814
#8BRIGHTVIEW LANDSCAPES LLC36282714
#9NEXT MILE INC319378313
#10UNITED PARCEL SERVICE INC2180012
#11SAKARA LLC442953012
#12SUNBELT RENTALS INC50057912
#13ASPLUNDH TREE EXPERT LLC10132812
#14PRODUCTORA AGRICOLA IND DEL NOROESTE SA DE CV55929412
#15WORLDWIDE TECH INC413604611
#16WLLC TRANSPORT INC375952911
#17J B HUNT TRANSPORT INC8080611
#18PIKE ELECTRIC LLC16518211
#19AUTO HAUL EXPRESS LLC432932511
#20MILLENNIUM INC252918511
#21WINDSTREAM COMMUNICATIONS LLC149666210
#22STAR FLEET TRUCKING INC49342410
#23BIG D RECYCING LLC217343210
#24CALIFORNIA TRUCKING COMPANY LLC278920710
#25AUTOTRANSPORTES ROMEDU SA DE CV11482599

Recent Inspections

Latest inspections where 393.43 was cited • 23,816 total events • Page 1 of 953

Recent Inspections with 393.43

Showing 25 of 23,816

fmcsa-inspections
Recent Inspections with 393.43
DateReport #StateLevelOOS
Apr 2, 202687486770ILLevel 1Yes
Apr 2, 202687486513NCLevel 1Yes
Apr 2, 202687486397NCLevel 1Yes
Apr 1, 202687459995NCLevel 2Yes
Apr 1, 202687486259NCLevel 1Yes
Apr 1, 202687486073NCLevel 1Yes
Apr 1, 202687485836NCLevel 1Yes
Apr 1, 202687485980NCLevel 1Yes
Apr 1, 202687477684ILLevel 1Yes
Apr 1, 202687477682ILLevel 1Yes
Mar 31, 202687459879NCLevel 1Yes
Mar 31, 202687460003NCLevel 2Yes
Mar 31, 202687460177NCLevel 1Yes
Mar 31, 202687477184NMLevel 1Yes
Mar 31, 202687465948ILLevel 1Yes
Mar 30, 202687463266NMLevel 1Yes
Mar 30, 202687438929NCLevel 1Yes
Mar 30, 202687452993NCLevel 1Yes
Mar 30, 202687453530ILLevel 1Yes
Mar 30, 202687453625ILLevel 1Yes
Mar 30, 202687453638ILLevel 1Yes
Mar 30, 202687453697ILLevel 1Yes
Mar 29, 202687462529NMLevel 2Yes
Mar 28, 202687432580NCLevel 1Yes
Mar 27, 202687432504NCLevel 1Yes

Data sources & freshness

FMCSA Vehicle Inspections and Violations
Updated 3 months ago
Federal Motor Carrier Safety Regulations (49 CFR)
Unknown freshness

Related records

CategoryAll Vehicle Maintenance Violations
Browse all violation codes in the Vehicle Maintenance BASIC
IndexAll Violation Codes
FMCSR violation codes by BASIC category
ReferenceFMCSA Roadside Inspections
Inspection levels and procedures
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