# DiagonalOBDII — OBDII Drive Cycle App

> Automotive diagnostic app for mechanics to track vehicle drive cycles and emissions monitors. (iPhone/iPad app by Kyle Louderback.)

- Source: https://appshunter.io/ios/app/diagonalobdii/id6743419784 (this page in markdown: same URL + `.md`)
- Developer: [Kyle Louderback](https://appshunter.io/developer/1400068218)
- Category: Productivity, Utilities
- Price: Free with in-app purchases
- Rating: 5.00/5 from 1 App Store ratings · 1 written reviews indexed
- Age rating: 4+
- Requires: iOS 18.1 · 21 MB
- Languages: American English
- Released: 2025-08-07
- Data updated: 2026-08-22
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/diagonalobdii/id6743419784/reviews.md

## What is DiagonalOBDII?

Diagonal is designed specifically for mechanics who want to simplify and speed up vehicle drive cycles. Instantly track emissions monitors and diagnostic trouble codes (DTCs) live, ensuring accurate diagnostics and rapid vehicle readiness for inspection.

Key Features:

-Live Drive Cycle Monitoring: Clearly see the real-time status of emissions monitors as they run, complete, or require further action during your drive.

-Immediate Diagnostics: Quickly identify and address active trouble codes (DTCs) as they appear, eliminating uncertainty during drive cycles.

-Efficiency and Accuracy: Avoid unnecessary repeat drive cycles by verifying real-time monitor completion, ensuring vehicles pass inspection on the first try.

-Precise Drive Cycle Guidance: Monitor essential drive cycle parameters such as speed, RPM, engine temperature, and throttle position to meet exact diagnostic requirements.

-Professional Dashboard: Access all critical information quickly through a clear, easy-to-navigate interface tailored for automotive professionals.

-Instant Code Explanations: Quickly interpret trouble codes with straightforward, mechanic-friendly explanations.

Why Mechanics Trust Diagonal:
-Saves Valuable Time: Complete diagnostic drive cycles accurately the first time.

-Faster Inspections: Immediately identify vehicle readiness to streamline your workflow.

-Reduces Diagnostic Uncertainty: Clear, actionable data presented in real-time.

-Diagonal empowers professional technicians with the tools to perform diagnostics faster and more efficiently than ever before.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://diagonal-d070c.web.app/privacy.html

## Key features

- Live drive cycle monitoring
- Immediate diagnostic trouble code (DTC) identification
- Real-time emissions monitor status
- Precise drive cycle parameter guidance
- Professional, easy-to-navigate dashboard
- Instant code explanations

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Diagonal Premium Monthly | $12.99 | per month |
| Diagonal Premium Yearly | $99.99 | per year |
| Diagonal Premium Trial | $12.99 | per month |
| Shop Owner - Monthly | $17.99 | per month |


## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/diagonalobdii/id6743419784/reviews.md

### 1/5 — Free Version - Meh

*2025-10-30*

Couldn’t get it to connect to my OBDii MX+ adapter. No help or troubleshooting features to help fix the connection problem. Have to give it 1 star only based on connectivity failure.

**Developer response:** Thanks for your feedback, and we're sorry you had trouble connecting to your OBD-II MX+ adapter. We’re always working to improve compatibility and would love to help resolve this for you.

If you're open to it, we'd be thrilled to have you test using our own hardware—for free. It’s specially tuned to work smoothly with the app.

Please email us at support@drivecycle.app and we’ll get it sent out to you and help troubleshoot the connection issue. 

Thanks again for giving us a try!

## Frequently asked questions about DiagonalOBDII

### What is DiagonalOBDII used for?

DiagonalOBDII is used by mechanics to simplify and speed up vehicle drive cycles. It provides real-time tracking of emissions monitors and diagnostic trouble codes (DTCs) to ensure accurate diagnostics and vehicle readiness for inspection.

### Does DiagonalOBDII have ads?

No, DiagonalOBDII does not contain advertisements. The app is free to download and use, with optional in-app purchases for premium features.

### What subscription plans are available for DiagonalOBDII?

DiagonalOBDII offers several subscription plans, including a 'Diagonal Premium Trial' for $12.99/month with a free trial, 'Diagonal Premium Monthly' for $12.99/month, 'Shop Owner - Monthly' for $17.99/month, and 'Diagonal Premium Yearly' for $99.99/year.

### How does DiagonalOBDII help mechanics save time?

DiagonalOBDII saves mechanics valuable time by allowing them to complete diagnostic drive cycles accurately the first time. It streamlines workflows by immediately identifying vehicle readiness for faster inspections and reducing diagnostic uncertainty with clear, real-time data.

### What kind of drive cycle parameters does DiagonalOBDII monitor?

DiagonalOBDII monitors essential drive cycle parameters such as speed, RPM, engine temperature, and throttle position. This precise guidance helps users meet exact diagnostic requirements for vehicles.

### Is DiagonalOBDII available on multiple devices?

Based on the provided data, DiagonalOBDII is currently supported on iPhones. Information regarding Android or other platform compatibility is not available.

### How often is DiagonalOBDII updated?

The latest version of DiagonalOBDII is 2.3, which was last updated on February 15, 2026. This indicates a recent update, suggesting the app is actively maintained.

### What is the age rating for DiagonalOBDII?

DiagonalOBDII has an age rating of 4+. This suggests it is suitable for a wide range of users, including younger individuals, though its primary audience is professional mechanics.

## Version history (last 5 releases)

### 2.3.6 — 2026-08-21

Sensor picker in Live Drive Cycle

### 2.3.5 — 2026-08-01

AI and bug fixes.

### 2.3.4 — 2026-07-22

Bug fixes

### 2.3.3 — 2026-07-17

• Share diagnostic PDFs — full report or a customer-friendly summary
• Smoother/Smarter AI Mechanic chat with quick-reply suggestions
• Improved UI during Magic Analysis
• Job History to revisit past diagnostics
• Request an adapter straight from the app

### 2.3.1 — 2026-07-15

Upgraded AI Mechanic

## Apps similar to DiagonalOBDII

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Giotto ScanTool](https://appshunter.io/ios/app/giotto-scantool/id1294503417) | 3.3 (44) | Free | Productivity |
| [Shodann Incident Reporter](https://appshunter.io/ios/app/shodann-incident-reporter/id1609217316) | — | Free | Productivity |
| [SafeInCloud 1](https://appshunter.io/ios/app/safeincloud-1/id785120026) | 4.9 (2,341) | $49.99 | Productivity |
| [Kegel Pattern Library](https://appshunter.io/ios/app/kegel-pattern-library/id1239558477) | 2.6 (5) | Free | Productivity |
| [AI Chat & Essay Writer - Aivan](https://appshunter.io/ios/app/ai-chat-and-essay-writer-aivan/id6449188590) | 4.6 (202) | Free | Productivity |
| [OBDAI OBD2 Scanner & ELM327 AI](https://appshunter.io/ios/app/obdai-obd2-scanner-and-elm327-ai/id6741182859) | 4.4 (12) | Free | Productivity |

## More apps by Kyle Louderback

- [Fables - Bedtime Stories](https://appshunter.io/ios/app/fables-bedtime-stories/id6737703420)
- [PlanMySalesRoute](https://appshunter.io/ios/app/planmysalesroute/id6762305924)
- [9up-9down](https://appshunter.io/ios/app/9up-9down/id6762537531)
- [Momentum - Gym](https://appshunter.io/ios/app/momentum-gym/id6797039060)

All apps by Kyle Louderback: https://appshunter.io/developer/1400068218

## Related topics

[diagonalobdii](https://appshunter.io/ios/topics/diagonalobdii)

---

*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 2026-08-22.*