# OBD-II Scanning and Scan Reports in Upland > OBD-II scanning in Upland that records stored and pending codes, freeze-frame data and readiness monitors, then explains what the scan report means. Source: https://route66autorepairshop.com/diagnostics-and-inspections/obd-ii-scanning 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:** A scan report lists **stored and pending codes**, freeze-frame snapshots and **readiness monitors**. It points to a system; testing finds the part. OBD-II scanning at Route 66 Auto Repair in Upland reads what your car's computers have recorded and puts it on paper. OBD-II stands for on-board diagnostics, second generation, the self-monitoring system built into modern cars. We record the codes, the conditions when they set and the monitor status, then explain in plain words what the report does and does not prove. ## What does an OBD-II scan report show? - **Stored codes:** faults the computer confirmed, which usually turn on a warning light - **Pending codes:** faults seen once but not yet confirmed, often before any light comes on - **Freeze-frame data:** engine speed, temperature, load and fuel trim at the moment a code set - **Readiness monitors:** self-tests showing whether the emissions systems have finished checking themselves - **Module list:** which computers answered, including ABS, airbag, transmission and body modules on a full scan - **Permanent codes:** records some vehicles keep until the repair is proven, even after codes are cleared ## How is a generic scan different from a full-module scan? A basic handheld reader talks only to the engine computer using generic codes. That leaves out the anti-lock brakes (ABS), the airbag system, the body controller and, on many cars, the transmission. A full-module scan uses a shop scan tool to query every module the vehicle has and record manufacturer-specific codes, which are often more detailed than the generic ones. That difference matters when you are buying a car or chasing an odd problem. A dash with no lights can still hide stored faults in a module that does not control a warning lamp. That is why a full-module scan is part of every [deluxe pre-purchase inspection](https://route66autorepairshop.com/diagnostics-and-inspections/pre-purchase-vehicle-inspection). The standard behind all of this is worth knowing. OBD-II has been required on cars and light trucks sold in the United States since the 1996 model year, which is why the connector and the generic codes look the same from one brand to the next. Codes beginning P0 are the generic set that any reader can decode, while P1 codes are manufacturer-specific and need the right software to mean anything. Readiness monitors, which show whether the vehicle has finished its own self-tests, come from the same standard. ## Can a scan tell if codes were recently cleared? Often, yes. When someone clears codes with a reader, the readiness monitors reset to incomplete. A car with several incomplete monitors and a seller who says the light never came on deserves a closer look. The report records monitor status so you can see it for yourself. ## How we run and explain an OBD-II scan 1. **Connect:** We plug into the diagnostic port under the dash and confirm the VIN the computer reports. 2. **Read every module:** The scan tool polls each module and saves the codes, freeze-frame data and monitor status. 3. **Explain the report:** We go through the results with you in plain words and mark which codes are current. 4. **Plan the next test:** Codes that need follow-up get a test plan and an estimate before anything else is done. ## What's on an OBD-II scan report - VIN match between the computer and the vehicle - Stored, pending and permanent codes - Freeze-frame data for each code - Readiness monitor status - Module-by-module scan results - Plain-language explanation of the findings ## Which findings are need-now, and which can wait? **Need now:** - A code tied to a flashing light or active misfire - Airbag or ABS codes, which can mean those systems may not work in a crash or hard stop **Need later:** - A pending code with no symptoms, which we note and recheck - A small EVAP (fuel vapor) leak code, often a cap or hose ## How pricing and timing work The scan is the first step of a diagnosis, and the diagnostic fee stated at the counter covers the scan plus the testing that follows. If a code leads to an approved repair, the fee applies to it. When the check engine light is on, see [check engine light diagnostics](https://route66autorepairshop.com/engine-services/check-engine-light-diagnostics). Codes in body or lighting modules go through [electrical system diagnostics](https://route66autorepairshop.com/electrical-services/electrical-system-diagnostics). The repair-side page is [OBD-II scanning](https://route66autorepairshop.com/electrical-services/obd-ii-scanning) under electrical services. ## Frequently asked questions ### Will clearing the code fix the problem? No. Clearing a code turns off the light but leaves the fault in place. If the cause is still there, the code comes back, sometimes days later. Clearing codes also resets the readiness monitors, which can hide a problem from the next person who scans the car. ### Can you scan a diesel or a hybrid? Diesels are welcome and scan the same way, with extra data for the fuel and exhaust systems. If yours is a hybrid, tell us it's a hybrid at intake and we'll explain what we can take on for that model. ### Should I get a scan before a road trip? It is a good idea if a light has flickered or the car has felt off. A pending code found before a drive over the Cajon Pass is far easier to deal with in Upland than on the shoulder of the 15. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.