Comparison

J1939FaultCode vs Auto Diag Solution

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

Head to head
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.

About

Auto Diag Solution

Features
Read full description

Auto Diag Solution est une application de diagnostic automobile permettant d'identifier les pannes, consulter les codes défaut, suivre l'entretien des véhicules, accéder à un garage virtuel et bénéficier d'un assistant IA spécialisé. Conditions d'utilisation (EULA) : https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Politique de confidentialité : https://autodiagsolution.com/privacy

Screenshots

J1939FaultCode4 screens
Auto Diag Solution4 screens

Verdict

The call

The clearest difference is ads: Auto Diag Solution at none against J1939FaultCode's shown. Auto Diag Solution also leads on update cadence (every 5 days vs fortnightly) and device support (3 vs 1). On price, in-app purchases 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 and Auto Diag Solution sells 2 in-app purchases, starting at $6.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

J1939FaultCode ships an update fortnightly, Auto Diag Solution every 5 days. Both last shipped on November 5, 2026.

Scorecard3 real differences · 3 level
J1939FaultCode versus Auto Diag Solution: the parameters behind the verdict, then further details
ParameterJ1939FaultCodeAuto Diag Solution
PriceFreeFree
Update frequencyFortnightlyEvery 5 days — better
AdsYesNo — better
In-app purchasesYesYes
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS16.015.1 — better
Further details — not scored
Size14 MB51 MB
Age rating4+4+
Developer洋 刘Lopes Brice

In-app purchases

1 purchases

J1939FaultCode

One-time1
  • J1939 Pro$2.99
2 purchases

Auto Diag Solution

Subscriptions2
  • Auto Diag Pro Mensuel$6.991 Month
  • Auto Diag Pro Annuel$49.991 Year

Questions

Is J1939FaultCode free?
J1939FaultCode is free to download, with in-app purchases available.
Is Auto Diag Solution free?
Auto Diag Solution is free to download, with in-app purchases available.
Do J1939FaultCode or Auto Diag Solution have ads?
J1939FaultCode shows ads; Auto Diag Solution does not.
Which is updated more often, J1939FaultCode or Auto Diag Solution?
J1939FaultCode ships an update fortnightly, and Auto Diag Solution every 5 days. Most recently, J1939FaultCode was updated on November 5, 2026 and Auto Diag Solution on November 5, 2026.

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