Comparison

OTR Diagnostics vs ZDOBD

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

Head to head
About

OTR Diagnostics

This app helps heavy-duty truck owners diagnose and resolve common issues like fault codes, regen problems, and derates. It provides plain-language explanations of error codes, allows for bi-directional commands to fix issues, and monitors live truck data to prevent downtime.

Highlights
  • AI-powered fault code explanation
  • Bi-directional commands for repairs
  • Reset active/inactive fault codes
  • Run forced DPF/SCR regens
  • Live data monitoring
  • Fault code history tracking
Features
Read full description

OTR Diagnostics — Trusted by 10,000+ Truck Owners Dealing with regen problems, nonstop alerts, fault codes, and unexpected derates on your heavy duty truck? You are not alone. More than 10,000 truck owners and fleets trust OTR Diagnostics to take control, cut downtime, and avoid expensive dealer visits. Powered by OTR Assist + OTR LINK 2 This is more than a scan tool. OTR Assist is your AI partner, breaking down fault codes in plain language and helping you troubleshoot and decide if you can keep driving or need service now. Paired with OTR LINK 2, our proprietary Bluetooth adapter, you get faster connection speeds, more accurate fault code data, and more live data parameters than ever before. It is 5X better than previous hardware. Ask us how to get a FREE upgrade today. Commands That Keep You Moving With bi-directional commands built right into OTR Diagnostics, you are no longer stuck waiting on a shop to do what you can handle yourself. Reset active and inactive fault codes Reset the entire aftertreatment system Reset derates that slow you down Reset soot levels after a DPF service Run forced DPF or SCR regens right from the cab These commands put you back in control, saving you time, money, and downtime. Fault Code Insights Go beyond a flashing dash light. OTR Diagnostics helps you understand fault codes with the same level of detail as dealer software, but in plain language you can actually use. Decode your dash lights Uncover the root causes of issues Track how often a problem occurs Know which repairs or parts are needed Live Data Monitoring Want to know if your regen is working? Want to monitor exhaust temps, soot levels, or DEF? OTR Diagnostics lets you see your truck’s vitals in real time so you can spot issues before they stop you. Common live data parameters include: DPF fluid level DPF soot level EGR valve position Aftertreatment exhaust temps Boost pressure Accelerator pedal position Engine fuel delivery pressure Available live data may vary depending on the engine model your device is connected to. Explore Your History Recurring problems? OTR Diagnostics logs every fault code and command so you can see when issues happened, when they were cleared, and how long regens lasted. Proven. Tested. Backed by Support We run OTR Diagnostics, OTR Assist, and OTR LINK 2 on our own fleet of test trucks including late model Paccar MX engines to make sure everything works before it reaches you. That is why more than 10,000 drivers already trust OTR Diagnostics. Made in Michigan. Built for You We engineer, assemble, and ship right from our shop in Macomb, MI. If you are nearby, stop in and see us. Coverage We support a wide range of heavy duty engines: Cummins: CM871, CM2150, CM2250, CM2350 (2008–2024) Detroit Diesel: DD60, MBE, DD13, DD15, DD16 (2008–2024) Paccar: MX11, MX13 (2011–2024), PX7, PX9 (2008–2024) Volvo: D11, D13, D13TC, D16 (2014–2024) Mack: MP7, MP8, MP8HE, MP10 (2014–2024) For the full list of compatible models, call or text us at 586-799-4375. Need Help or Have Questions? Call or text us anytime at 586-799-4375 or email support@otrperformance.com.

About

ZDOBD

This diagnostic tool connects to portable diesel vehicle devices via Bluetooth to perform comprehensive vehicle checks. It allows users to view ECU information, diagnose and clear faults, monitor real-time data, and conduct specific tests like DPF regeneration.

Highlights
  • Bluetooth connectivity
  • ECU version information
  • Vehicle fault diagnosis and clearing
  • Real-time data flow monitoring
  • DPF regeneration
  • SCR testing
Features
Read full description

EPS001, a portable diesel vehicle diagnosis device, needs to be used with a cell phone, already supports IOS system,using bluetooth transmission mode. EPS001 can simultaneously perform communication testing on vehicles equipped with Cummins engine series, as well as vehicles in the United States and Europe, etc. It can view ECU version information, query vehicle maintenance faults, clear vehicle malfunctions, read real-time vehicle operation data flow, DPF regeneration, SCR test and other functions.

Screenshots

OTR Diagnostics4 screens
ZDOBD3 screens

Verdict

The call

The clearest difference is review sentiment: OTR Diagnostics at 55% against ZDOBD's 0%. OTR Diagnostics also leads on rating (4.0 vs 2.0) and ratings volume (99 vs 4). ZDOBD's advantage is iOS requirement (15.6 vs 17.6). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

OTR Diagnostics holds the better App Store score, 4.0 against 2.0. That said, the two scores are not equally well evidenced: OTR Diagnostics has 99 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 55% of OTR Diagnostics's written reviews are positive against 0% of ZDOBD's.

UpkeepUpdate frequency

OTR Diagnostics ships an update fortnightly, ZDOBD monthly. The most recent releases landed on September 23, 2026 and September 8, 2026 respectively.

Scorecard5 real differences · 5 level
OTR Diagnostics versus ZDOBD: the parameters behind the verdict, then further details
ParameterOTR DiagnosticsZDOBD
PriceFreeFree
Rating4.0 (99 ratings) — better2.0 (4 ratings)
Positive reviews55.2% of reviews — better0.0% of reviews
Number of ratings99 — better4
Update frequencyFortnightly — betterMonthly
AdsNoNo
In-app purchasesNoNo
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.615.6 — better
Further details — not scored
Size266 MB22 MB
Age rating4+4+
DeveloperOTR Performance深圳市正德友邦科技有限公司

Customer experience

OTR Diagnostics

All ratings99 ratings
Positive70.7%
Neutral7.1%
Negative22.2%
Written reviews58 reviews
Positive55.2%
Neutral10.3%
Negative34.5%

ZDOBD

All ratings4 ratings
Positive25.0%
Neutral0.0%
Negative75.0%
Written reviews2 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and requests

OTR Diagnostics

Reported bugs

10 issues
  • App constantly disconnects from device
  • Generic code option disappeared
  • Forced regen is no longer consistent
  • AI assistant not working
  • App asks to do things not available in app
Show 5 more
  • Bluetooth connection rejects
  • App doesn't work without data connection
  • Forced regen not activating after updates
  • Login authentication errors
  • Cannot start regen process on newer models

Requested features

5 requests
  • Remember email address for login
  • Allow offline functionality without data connection
  • Add option to change speed
  • More detailed diagnostic information
  • Allow basic subscription to work on multiple VINs

ZDOBD

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

OTR Diagnostics

No in-app purchases

None

ZDOBD

No in-app purchases

Questions

Is OTR Diagnostics free?
OTR Diagnostics is free to download, with no in-app purchases.
Is ZDOBD free?
ZDOBD is free to download, with no in-app purchases.
Which has better reviews, OTR Diagnostics or ZDOBD?
OTR Diagnostics is rated higher. OTR Diagnostics averages 4.0 out of 5 from 99 ratings, while ZDOBD averages 2.0 from 4 ratings.
Do OTR Diagnostics or ZDOBD have ads?
Neither OTR Diagnostics nor ZDOBD shows ads.
Which is updated more often, OTR Diagnostics or ZDOBD?
OTR Diagnostics ships an update fortnightly, and ZDOBD monthly. Most recently, OTR Diagnostics was updated on September 23, 2026 and ZDOBD on September 8, 2026.

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