Used 2020 BMW Pre-Purchase OBD2 Scan: Stored, Pending and BMW-Specific Faults
Last reviewed · OBDCode UK editorial
A generic OBD2 reader can retrieve emissions-related stored, pending and permanent codes. A BMW-capable tool may reach more modules. Neither scan proves the car is healthy on its own; treat it as one part of a pre-purchase check and do not clear codes for a seller.
What a 2020 BMW scan can and cannot prove
A scan gives you a snapshot. It can show reported faults, code status, freeze-frame data and emissions readiness. A wider tool may also find complaints in the gearbox, airbags, ABS and body modules.
It cannot judge worn brakes, a noisy bearing, an oil leak or how the gearbox behaves on the road. An intermittent fault may stay quiet during a short viewing.
Use the scan with a cold start, dashboard lamp check, service history, road test and proper inspection.
Verdict: A clean scan is useful, but it is not a clean bill of health. A serious code, missing module or recently reset monitor is a reason to ask questions before money changes hands.
Scope: This page does not report first-party vehicle tests.
Generic OBD modes versus BMW module access
A generic reader mainly deals with emissions-related engine data. That may be enough to find a stored engine fault or an incomplete readiness monitor.
For the gearbox, airbags, ABS and body electronics, you need software that says it covers BMW systems. Even then, check the exact model and year. “Full system” is catalogue language, not a promise that every menu works on your car.
| DIY tool | Published coverage and limit | Published UK price | Update and licence terms |
|---|---|---|---|
| iCarsoft BMM V3.0 | The global manufacturer page lists BMW, Mini and Rolls-Royce from 1996 to 2025. It also says functions vary by model, year and ECU. | £169 current price; £195 regular price from the UK outlet | The global manufacturer page says lifetime free updates, no subscription and card-reader updates using a PC. |
| Autel MaxiAP AP200 with BMW package | The global manufacturer page describes all-system diagnostics and broad European coverage. It does not confirm a particular 2020 BMW, so check BMW coverage before buying the package. | The UK retailer displays £46 and £57 without clearly labelling their relationship. | The global manufacturer page includes one vehicle software package and says more coverage needs an in-app purchase. It does not state the renewal period. |
Ask what jobs you need the tool to do. Engine codes only is one job. Engine, gearbox, airbags and ABS is another.
Oil reset on the box is not oil reset on a 2018 Focus.
Stored, pending, permanent and BMW-specific faults
These labels are clearest in generic emissions OBD. BMW modules and scanner apps may use different wording.
Stored or confirmed means the reader reports a fault retained in OBD memory. Record the code and any freeze-frame data.
Pending means the OBD system has noticed a possible fault that has not yet become confirmed. It may disappear or become stored after further monitoring.
Permanent is a separate emissions-code category. Do not assume that pressing erase has removed it. Check what the reader reports after the vehicle has run its own monitors.
BMW-specific faults come from manufacturer diagnostics or modules outside generic engine access. The description points you towards a system. It does not prove the named part needs replacing.
Read the status shown by the actual tool. Do not apply generic stored and pending rules to every BMW module label.
What to record before you buy
Save the full report before anyone clears anything. Record:
- registration, visible VIN and mileage
- date, time and whether the engine was cold or warm
- dashboard lamps before and after starting
- tool, app and software version
- every module attempted and reached
- every code, status and module
- freeze-frame data where available
- emissions readiness state
- battery voltage shown by the tool
- modules that would not communicate
Photograph the dashboard and keep the complete report. A copied code without its module, status or mileage is thin evidence.
Seller-controlled red flags
Be wary if the seller will not allow a cold start or an independent scan.
If an expected warning lamp does not illuminate during the normal lamp check, treat that as an abnormal result until the correct behaviour is confirmed. Do not assume from one viewing that someone disabled it.
Several incomplete readiness monitors can follow a recent code clear or battery disconnection. They can have other causes as well. There is no useful universal count that proves the seller cleared codes.
Slow down if:
- the seller cleared faults before you arrived
- the report does not match the car or mileage
- important modules refuse communication
- a fault returns during the viewing
- the seller will not let you save the original report
- the explanation jumps straight from a code to one cheap replacement part
Current DVSA guidance says an engine malfunction lamp that is inoperative or indicating a malfunction is a major MOT defect for vehicles within scope. That makes the lamp check worth doing properly.
FAQ: clearing codes, readiness monitors and scan records
Should I clear the codes before the test drive?
No. You would remove evidence and reset useful emissions information. Save the original report and leave the car as presented.
Can a seller hide a fault by clearing codes?
Clearing may switch off the warning lamp until the fault is detected again. Readiness monitors may also show that their checks are incomplete. Neither result proves dishonesty, but both deserve an explanation.
Does a pending code matter?
Yes. It shows that the OBD system has noticed something. It may not become a confirmed fault, so record it and see whether it returns during the agreed inspection.
Does a permanent code mean the fault is still present?
Not by itself. It is an emissions-code category that may remain after an ordinary erase command. Consider it with current codes, warning lamps, readiness and the repair history.
Does a clean engine scan cover the whole BMW?
No. A generic reader may never ask the gearbox, airbags, ABS or body modules. Check the scan report for a module list rather than relying on the words “no codes”.
What should I take to a garage?
Take the unedited report, module list, code statuses, freeze-frame data, readiness state, mileage and dashboard photographs. Do not clear the car first.
Public source note, 8 September 2026: Coverage, UK prices and update terms were checked against the manufacturer and named retailer pages linked in the table. The DVSA MOT inspection manual was checked for engine malfunction lamp rules. These are published claims and public procedures, not results from a tested vehicle.
Related
Related
General guidance, not professional advice.