# J1939FaultCode — ast J1939 Fault Code Lookup

> ast J1939 Fault Code Lookup (iPhone/iPad app by 洋 刘.)

- Source: https://appshunter.io/ios/app/j1939faultcode/id6778431735 (this page in markdown: same URL + `.md`)
- Developer: [洋 刘](https://appshunter.io/developer/6775317751)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 16.0 · 11 MB
- Languages: Chinese
- Released: 2026-06-16
- Data updated: 2026-07-17
- User reviews in markdown: https://appshunter.io/ios/app/j1939faultcode/id6778431735/reviews.md

## What is J1939FaultCode?

J1939 FaultCode is a practical offline diagnostic reference tool for commercial vehicle technicians, fleet maintenance teams, and engineers.

Quickly look up J1939 SPN parameters, FMI definitions, combined DTC meanings, and brand-specific fault code mappings. The app is designed for fast field use, with built-in data and no internet connection required for core lookup features.

Main features:

Search SPN codes by number or keyword
View FMI definitions with clear explanations
Query DTC combinations using SPN + FMI
Check common causes and repair suggestions
Browse brand-specific fault code mappings
Save frequently used codes to Favorites
Review recent lookup history
Switch between English and Chinese
Works offline after installation
Whether you are troubleshooting engine, aftertreatment, fuel, sensor, electrical, or communication faults, J1939 FaultCode helps you find useful reference information quickly and consistently.


## Version history (last 4 releases)

### 1.3 — 2026-07-16

• CAN signal database: 2,900+ messages, 16,000+ signals
• Pro upgrade: ad-free + unlimited signal details

### 1.2 — 2026-06-21

Bug fixes

### 1.1 — 2026-06-20

fix bug of language switch options

### 1.0 — 2026-06-16

No release notes.

## More apps by 洋 刘

- [Signed Base Converter](https://appshunter.io/ios/app/signed-base-converter/id6779268811)

All apps by 洋 刘: https://appshunter.io/developer/6775317751

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-17.*