Direct answers: Will 393.77 put your truck OOS? How many CSA points? What to do after citation. Data from 13M+ inspections.
Ranks #1,713 of 3,146 FMCSR codes by citation frequency • OOS rate of 0.0% is below the FMCSR-wide average of 33.3%.
Heating system on commercial motor vehicle used to heat the cab or body is not operative or malfunctioning.
Direct answers grounded in TruckCodex inspection data
No. Across our 13 million inspection records, 393.77 citations have never resulted in an out-of-service order—the OOS rate is 0.0%. All 41 all-time citations in our database were not placed out of service. This makes 393.77 significantly less severe than the all-FMCSR average OOS rate of 31.4%. You will be cited, but your truck stays in operation.
A single 393.77 citation carries a CSA severity weight of 2 points. This is a standard Vehicle Maintenance violation. The total points on your CSA record depend on when the violation occurred—points accumulate and decay over time according to FMCSA's 30-day moving-window system. One citation means 2 points added on the citation date; those points then age out after 30 days.
Immediate steps:
No, 393.77 is relatively minor. Our inspection data shows it ranks #1687 of 3,036 FMCSR codes by citation volume (only 41 all-time), and it has never been placed out of service. Compare this to peer codes in Vehicle Maintenance: inoperable lamps (393.9) have a 6.9% OOS rate and 180,097 citations; slack adjuster defects (393.47E) show a 0.0% OOS rate but 180,363 citations. 393.77 is cited infrequently and rarely triggers enforcement action.
Yes, you can contest any citation through FMCSA's DataQs RDR (Roadside Inspection Data Dispute Resolution) system. For 393.77, your contestation strategy depends on the evidence: if the inspector's documentation is incomplete or inaccurate (no photo, wrong vehicle ID, no detail on the defect), you can challenge the factual accuracy. If the heater was operational and the citation was in error, submit proof of repair or maintenance records showing the system worked. DataQs typically resolves disputes within 30–45 days.
In the last 180 days, our inspection records show Texas had the highest citation count with 2 citations and a 0.0% OOS rate. The low national volume (only 3 citations in the last 12 months and 0 in the last 90 days) means 393.77 is infrequently enforced across all states. Texas is the only state with recent activity in our top-states data.
Repair it within a reasonable timeframe—not emergency-urgent. Our 90-day trend shows zero citations in the last 90 days and only 3 in the last 12 months, indicating 393.77 is rarely re-cited during compliance audits. However, a non-operative heating system is a maintenance failure and a comfort/safety issue for the driver. Fix it before the next roadside inspection to avoid accumulating violations or repeat citations.
Both. Vehicle Maintenance violations (BASIC 5 category) appear on both the driver's and the carrier's CSA records. The carrier receives a copy of the citation and the violation is logged against the carrier's safety profile; the driver's PSP record also reflects the citation. For fleet managers: 393.77 signals a gap in pre-trip or post-trip vehicle inspection procedures. For drivers: the violation affects your personal driving record and CSA history.
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Census, SAFER, SMS, Licensing & Insurance (L&I), roadside inspections, crashes, and authority history.
Vehicle recall campaigns, defect investigations, and consumer safety complaints (SCRS).
Cross-border carrier registry and Canadian recall campaigns where applicable.
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