Comparison

Crewchief Auto vs J1939FaultCode

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Crewchief Auto

Manage your vehicles with this app. Read diagnostic trouble codes, view live engine data, and get AI-powered reports with repair guidance and cost estimates. Track maintenance, store records, and set reminders for unlimited vehicles.

Highlights
  • Read and clear diagnostic trouble codes (DTCs)
  • View live engine data
  • AI diagnostic reports with repair guidance
  • Track unlimited vehicle types
  • Store photos, documents, and service records
  • Set maintenance reminders
Features
Read full description

Crew Chief is your all-in-one vehicle management app. Connect a Bluetooth OBD2 scanner to read diagnostic trouble codes, view live engine data, and get AI-powered diagnostic reports with repair guidance and cost estimates. DIAGNOSTICS & SCANNING • Read and clear diagnostic trouble codes (DTCs) via Bluetooth OBD2 • View live engine data — RPM, speed, coolant temp, fuel trim, and more • Get AI diagnostic reports with severity ratings, repair steps, and part recommendations • Look up any OBD2 code with detailed explanations VEHICLE MANAGEMENT • Track unlimited vehicle types — cars, trucks, SUVs, motorcycles, boats, tractors, RVs, ATVs, and more • Store photos, documents, and service records • Set maintenance reminders and track tasks • Manage your entire fleet from one dashboard DREAM CARS • Set alerts for vehicles you're looking for • Search eBay Motors and marketplace listings • Save and compare listings PROJECTS • Track maintenance tasks across all vehicles • Organize by priority and status • Estimate costs and schedule due dates Works with any ELM327-compatible Bluetooth OBD2 scanner. Free to use with optional Pro subscription for unlimited AI diagnostics.

About

J1939FaultCode

Features
Read full description

J1939 Fault Code Lookup is the offline diagnostic reference for commercial-vehicle technicians, fleet mechanics and field engineers. Decode SAE J1939 diagnostic trouble codes in seconds — no internet connection required. KEY FEATURES ■ SPN Search Look up Suspect Parameter Numbers by number or keyword. See full parameter definitions including unit, range and resolution. ■ FMI Reference 23 bundled FMI definitions (0–21 and 31). Uncovered identifiers are reported explicitly. ■ DTC Diagnosis Look up covered SPN + FMI combinations. The fault database has 61 SPNs, 23 FMIs and 57 brand mappings. FMI-based guidance is general reference, not manufacturer/model-specific diagnosis. ■ Equipment Fault Records Organize an equipment alias, date, multiple fault codes, notes and review status. Draft and preview for free; Pro saves, edits and exports text reports. Uncovered codes can be recorded without invented definitions. ■ Brand Fault Codes Cross-reference OEM codes from Cummins, Bosch, Weichai, Yuchai and common aftertreatment systems. ■ CAN Signal Database 2,900+ J1939 messages and 16,000+ signal definitions with start bit, length, scaling, offset, range and enum values — perfect for calibration and network troubleshooting. ■ Favorites & History Bookmark frequently used codes; your search history is saved automatically. ■ 100% Offline Every database is built into the app. Underground garage, remote job site, no signal — it just works. PRO UPGRADE (one-time purchase) • Removes all ads (banner + interstitial) • Unlimited signal database detail views (free tier: 3 per day) • Save/edit local equipment records and export multi-fault text reports One-time purchase. Saved records remain viewable, deletable and exportable after revocation. Existing basic lookups, favorites/history and single-code copying/sharing stay free. WHO IS IT FOR Truck, bus and heavy-equipment technicians, service engineers, fleet managers, automotive electronics and calibration engineers, vocational students. DISCLAIMER All information is provided for reference only. Always consult the OEM's official service documentation before performing repairs. Records stay on your device, with no account or cloud sync. Export before deleting the app. Lookups and records work offline; purchases, restores and ads need a network connection.

Screenshots

Crewchief Auto4 screens
J1939FaultCode4 screens

Verdict

The call

The clearest difference is in-app purchases: Crewchief Auto at none against J1939FaultCode's 1. Crewchief Auto also leads on ads (none vs shown) and device support (3 vs 1). On price, update cadence and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. J1939FaultCode sells 1 one-off in-app purchase. Crewchief Auto asks for nothing beyond the download.

UpkeepUpdate frequency

Crewchief Auto ships an update every 3 weeks, J1939FaultCode fortnightly. The most recent releases landed on October 31, 2026 and November 5, 2026 respectively.

Scorecard3 real differences · 7 level
Crewchief Auto versus J1939FaultCode: the parameters behind the verdict, then further details
ParameterCrewchief AutoJ1939FaultCode
PriceFreeFree
Rating5.0 (3 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings3 — better—
Update frequencyEvery 3 weeksFortnightly — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFreemium—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.1 — better16.0
Further details — not scored
Size35 MB14 MB
Age rating4+4+
DeveloperDavid Justice洋 刘

In-app purchases

None

Crewchief Auto

No in-app purchases

1 purchases

J1939FaultCode

One-time1
  • J1939 Pro$2.99

Questions

Is Crewchief Auto free?
Crewchief Auto is free to download, with no in-app purchases.
Is J1939FaultCode free?
J1939FaultCode is free to download, with in-app purchases available.
Do Crewchief Auto or J1939FaultCode have ads?
J1939FaultCode shows ads; Crewchief Auto does not.
Which is updated more often, Crewchief Auto or J1939FaultCode?
Crewchief Auto ships an update every 3 weeks, and J1939FaultCode fortnightly. Most recently, Crewchief Auto was updated on October 31, 2026 and J1939FaultCode on November 5, 2026.

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