Gretio

Though not super slick and sometimes crashes, this app is an absolute powerhouse for dealing with complex, intermittent sensor issues in modern diesels. Without question, I would not have been able to resolve my issue without it. Be sure to track down their troubleshooting guide if you are chasing diesel emissions issues. The guide brings context to the data and maps a path to resolution.

Found a forum where the author said he had a truck like ours with similar issues, and that he had an app for that! Bought the OBD link mentioned for $138 on Amazon and paid the $20 for the app. We also replaced the Nox sensor 1 to start fresh(er). Hooked the OBDlink up to Bluetooth, used the Gretio app to run the DPF Service Regen, (so cool to watch the soot percentage come down)then the DPF Reset, then the Reductant System Malfunction Warning Service Bay Test and all is right in the world again.

Look, I’m a Soldier stationed overseas in Italy, NO GMC dealerships here. I got the dreaded “Exhaust Fluid Quality Poor” message in my 2017 Canyon, and I was freaking out, because I still have 3 years left in Italy. I swapped both NOx sensors and the speed limit warning did not go away, I kept searching and I came across the OBDLink MX+ and the Gretio App, I ran the Reductant System Malfunction Warning Service Bay Test through the Gretio App and BOOM! Problem solved! I’ll keep paying the yearly subscription out of gratitude for this fantastic app! Thank you!

Many options and deep diagnostics on every module for these newer models! Great addition for a technician or at home mod fanatic!

The combination of this app and its concise diesel emission trouble shooting guide are invaluable! Using them, along with OBDlink MX+, I was able to resolve the “Exhaust Fluid Quailty Poor” issue that was on the verge of bricking my LWN diesel. Being able to conduct diagnostic tests to resolve diesel emission issues removes the haunting fear of diesel ownership. I give thanks to the developer for sharing his skill and automotive passion!

Could you please fix the issue of not connecting to the OBD Bluetooth device. It shouldn’t take 10 minutes and 87 attempts

When all other scanners and code readers failed, this app let me do a service bay test that cleared that code after I changed my NoX sensors. Cannot say enough good things!

Don’t waste your money on this one Very basic do nothing app that advertises as equal to torque 1

I was excited to purchase this app and happily pay for quality. I was highly dissatisfied given the description in the App Store did not give caveat that there is not a very long list of supported GM vehicles. I had to find out after sending an email to the developer. Once I got that email I had to go to the Gretio support site and find a link of supported vehicles. This link should be front and center in the app description so an informed decision can be made before purchase.

When CHanging injectors on a LML duramax you have to enter the code from the new injector both in the ecm and in the GPCM. This only seems to let you do the ecm, so you get an incompatibility code on your truck!!! Fix this please!!!!