# Auto Diagnostic Testing in Upland > Something feels wrong but you can't name it? Auto diagnostic testing in Upland finds the cause, states the fee up front and ends in a written estimate. Source: https://route66autorepairshop.com/diagnostics-and-inspections/auto-diagnostic Updated: 2026-09-17 Business: Route 66 Auto Repair, 1775 W Foothill Blvd, Upland, CA 91786, (909) 608-7699 Hours: Monday to Friday 8 AM–5 PM, Saturday 8 AM–2 PM, Sunday closed **TLDR:** Tell us the symptom, and we **confirm it**, test the likely causes and hand you **written findings** plus an estimate before any repair begins. An auto diagnostic at Route 66 Auto Repair in Upland is for the car that feels wrong when you can't say why. A technician confirms the symptom, scans the computer, tests the likely causes and writes down what failed and how we know. You get the findings and a written estimate before any repair, and the diagnostic fee applies to approved related work. ## When should you book an auto diagnostic? - A vibration, smell or sound that is new and will not go away - The car drives differently after a pothole, a hot day or a long grade - A warning light that comes and goes - A parts store gave you a code but no clear answer - You already replaced a part and the problem is still there ## Why do we start with your description? The most useful diagnostic tool is the driver. You know that the shudder only happens between 40 and 50 mph, or that the smell shows up after the drive home from Ontario. We write your words on the repair order, then try to reproduce the problem on a road test before touching anything. A symptom we can feel ourselves is a symptom we can chase with confidence. If we cannot reproduce it, we say so. Some faults need the car to sit overnight or run a specific route before they appear. We would rather tell you that than replace a part on a hunch. For light-on complaints, the next step is often [check engine light diagnostics](https://route66autorepairshop.com/engine-services/check-engine-light-diagnostics). For trouble with power, lights or modules, it is [electrical system diagnostics](https://route66autorepairshop.com/electrical-services/electrical-system-diagnostics). ## Our auto diagnostic process 1. **Interview:** The service writer asks when, where and how often it happens, and what changed before it started. 2. **Reproduce:** A technician drives or runs the vehicle to feel, hear or see the symptom. 3. **Narrow it down:** Scan data, visual checks and targeted tests rule causes in or out one at a time. 4. **Report:** You get the cause, the evidence and a written estimate sorted into need-now and need-later. ## What's included in an auto diagnostic - Symptom interview written on the repair order - Road test to confirm the complaint - Computer scan with codes and live data reviewed - Targeted tests for the suspected system - Photos of the failed part when the part is the point - Written findings and estimate ## Which findings are need-now, and which can wait? **Need now:** - Symptoms that affect braking, steering or visibility - Smoke, burning smells or fresh fluid on the ground **Need later:** - A faint new noise with no change in how the car drives - An intermittent light with no drivability change, once we have checked it ## How pricing and timing work Most of the time goes into catching the fault. A constant problem is quicker to pin down than one that shows up once a week. The counter states the diagnostic fee before testing, and it applies to the approved related repair. Our [pricing page](https://route66autorepairshop.com/pricing) explains how estimates are built. AAA members save 10% on parts and labor, up to $75, with the card at time of service. ## Frequently asked questions ### What if you can't find anything wrong? Then we tell you what we tested, what passed and what we would try next. Sometimes the best step is to drive the car until the symptom is stronger and bring it back. You still get written notes, so the next visit starts where this one ended. ### Can I wait while you diagnose it? Sometimes. Wait or drop-off is decided at intake, based on the complaint and what the board can hold that day. For intermittent problems, drop-off usually works better because the technician may need several tries to catch it. ### Are your technicians certified? Yes. Our technicians are [ASE](https://www.ase.com/) certified, and Route 66 Auto Repair is an AAA Approved Auto Repair shop with 35+ years in business on Foothill Blvd. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.