--- title: How Transmission Diagnosis Works | A-1 Transmission url: https://a1transmissionrenonv.com/faq/diagnosis/ business: A-1 Transmission (A-1 Transmission Inc) address: 670 East Grove Street, Reno, NV 89502 phone: (775) 829-1333 hours: Monday to Friday 7:30 am to 5:30 pm, closed Saturday and Sunday type: Transmission shop and auto repair shop in Reno, Nevada, since 1968; walk-ins welcome during business hours, appointments suggested --- - [Home](https://a1transmissionrenonv.com/) - [FAQ](https://a1transmissionrenonv.com/faq/) - How diagnosis works # How diagnosis works At A-1 Transmission, diagnosis comes before any repair: "We will diagnose the situation to determine the kind of service you need." The shop looks at the vehicle, finds the cause and explains what it needs. [Call (775) 829-1333](tel:+17758291333) [Get directions](https://www.google.com/maps/dir/?api=1&destination=A-1+Transmission+Inc,+670+East+Grove+Street,+Reno,+NV+89502&destination_place_id=ChIJZfhkfH4_mYARqc7eV_uhOws)[What is it doing?](https://a1transmissionrenonv.com/symptoms/#checker) 1968 In business since [4.6 ★ 112 Google reviews](https://maps.google.com/maps?cid=809418658926218921) ATRA Member shop M-F 7:30 am to 5:30 pm A good diagnosis saves money because it makes sure the repair matches the problem. The shop's promise is "We will never try to sell you a service you don't need," and a review from November 2022 says: "Outstanding integrity,on time .as good as new." These are the questions drivers ask most. The longer version is on the [transmission diagnosis page](https://a1transmissionrenonv.com/services/transmission-diagnosis/). ## Before you arrive ### What should I tell the shop? The year, make, model and engine, the mileage, what the vehicle is doing, when it started and whether a warning light is on. The [call checklist](https://a1transmissionrenonv.com/call/) has the whole list. ### Can I describe it on the phone and get an answer? The shop can tell you what a symptom usually means. Only a look at the vehicle tells what it needs. ### Should I keep driving it until my appointment? Call first. Our [driving with a slipping transmission](https://a1transmissionrenonv.com/guides/driving-with-a-slipping-transmission/) guide explains when to stop. ## What gets looked at ### What does the mechanic check first? Usually fluid level and condition, any leaks, stored trouble codes, and how the vehicle drives. A road test often shows what a parking lot cannot. ### Does a check engine light mean my transmission is bad? Not always. The light covers the whole vehicle. If the code is in the P07xx family it relates to the transmission; see [check engine light and transmission codes](https://a1transmissionrenonv.com/symptoms/check-engine-light-transmission-codes/). ### Do you diagnose manuals and 4x4s too? Yes. The same approach applies to automatic and standard transmissions, clutches and transfer cases. ## What you hear afterward ### What will I be told? What is wrong, what the repair options are, and whether it is a small repair or a large one. The shop explains it before any work. ### What if the problem is outside the transmission? Then the diagnosis says so. Many things that feel like a transmission problem come from sensors, wiring, engine trouble or the fluid. ### What does the diagnosis cost and how long does it take? Call (775) 829-1333 and ask; the shop will tell you for your vehicle. ## Next steps ### Do I have to go ahead with the repair? No. The diagnosis tells you what the vehicle needs. The decision is yours. ### Sources - [A-1 Transmission, Services page (old site, read September 6, 2026)](https://a1transmissionrenonv.com/services/) - [On-board diagnostics, Wikipedia](https://en.wikipedia.org/wiki/On-board_diagnostics) Keep reading ## Related pages [Transmission diagnosis Transmission diagnosis is the step where a mechanic finds out what is actually wrong before choosing a repair.](https://a1transmissionrenonv.com/services/transmission-diagnosis/)[What to tell us when you call Have the year, make, model and mileage ready, then describe what it does and when it happens.](https://a1transmissionrenonv.com/call/)[What to expect at the shop Expect a phone call or a walk-in during business hours, a diagnosis, and a plain explanation of what your vehicle needs before any work.](https://a1transmissionrenonv.com/faq/what-to-expect/)[Signs your transmission needs attention The signs your transmission is going out are slipping gears, shifts that are harsh or late, a delay going into Drive or Reverse.](https://a1transmissionrenonv.com/guides/signs-your-transmission-is-failing/) More questions ## Other question pages [Appointments and walk-ins Appointments are suggested, and walk-ins are welcome during business hours, Monday to Friday from 7:30 am to 5:30 pm.](https://a1transmissionrenonv.com/faq/appointments-and-walk-ins/)[Hours and location A-1 Transmission is open Monday to Friday from 7:30 am to 5:30 pm and closed Saturday and Sunday, at 670 East Grove Street, Reno, NV 89502.](https://a1transmissionrenonv.com/faq/hours-and-location/)[Payment A-1 Transmission accepts Visa, Mastercard and cash.](https://a1transmissionrenonv.com/faq/payment/)[What to expect at the shop Expect a phone call or a walk-in during business hours, a diagnosis, and a plain explanation of what your vehicle needs before any work.](https://a1transmissionrenonv.com/faq/what-to-expect/) ## Not shifting right? 670 East Grove Street, Reno, NV 89502 Monday to Friday, 7:30 am to 5:30 pm [What to tell us when you call](https://a1transmissionrenonv.com/call/) [(775) 829-1333](tel:+17758291333)