Pre-Purchase OBD-II Scan

Expert service in Atascadero · Honest diagnostics · Quality parts

Signs Your Vehicle Needs This Service

Any used vehicle purchase from a private seller: an OBD-II scan before purchase takes under an hour and gives you documented information about the vehicle's current fault status across all accessible modules
Dealer sale where the check engine light is off but the service history is incomplete: dealers sometimes clear codes during reconditioning, and a permanent code review shows whether this occurred
Vehicle with a suspicious number of incomplete readiness monitors: a vehicle driven normally for months should have most monitors complete; multiple incomplete monitors suggest a recent battery disconnect or code clear
Vehicle being purchased remotely or sight-unseen: an independent pre-purchase scan provides documented findings you can review before finalizing the purchase
Vehicle described as recently repaired with the check engine light cleared: a permanent code check tells you whether the repair actually resolved the underlying fault

Pre-Purchase OBD-II Scan

Stored, Pending, and Permanent Code Review

We retrieve all stored codes representing confirmed current faults, pending codes representing faults detected once but not yet confirmed, and permanent codes indicating faults detected before a repair was confirmed. Permanent codes are the most important category for pre-purchase evaluations because they cannot be concealed by a code clear.

Readiness Monitor Completion Analysis

We review every readiness monitor and note which are complete and which are incomplete. On a vehicle with normal driving history most monitors should be complete. Multiple incomplete monitors on a vehicle that has supposedly been driven regularly are a significant finding that warrants additional investigation before purchase.

Freeze Frame Evidence Review

For any stored codes, we review the freeze frame data to understand when the fault occurred and under what conditions. Freeze frame data that contradicts the vehicle's claimed history or usage pattern is worth noting before purchase.

Multi-Module Code Check

We scan beyond the engine module to check the ABS module, airbag module, transmission module, and body control module for any codes the seller may not have known about or addressed.

Written Pre-Purchase Report

We provide a written summary of all codes found, the readiness monitor status, any permanent codes identified, and our interpretation of what the findings indicate about the vehicle's current fault status and recent history.

What to Expect: Typical Service Times

Full OBD-II pre-purchase scan with all code categories: 30 to 45 minutes
Multi-module scan: 15 to 30 minutes additional
Written report preparation: 10 to 15 minutes
Total pre-purchase OBD-II scan: 45 to 75 minutes

How Our Technicians Approach a Pre-Purchase OBD-II Scan

When a vehicle comes in for a pre-purchase scan, we begin with the permanent code check because permanent codes are the most revealing finding in a pre-purchase context. A vehicle with permanent codes has known faults that were detected and not yet confirmed as resolved, which is critical information before any purchase decision.

We then check readiness monitor completion status. A vehicle with most monitors incomplete suggests a recent battery disconnect or code clearing event. The combination of recent monitor clearing and permanent codes is a significant finding indicating the seller may have attempted to conceal known problems.

We retrieve all stored and pending codes from all accessible modules, review each one with freeze frame context, and compile everything into a written report. We explain every finding clearly and give our interpretation of what the OBD-II data suggests about the vehicle’s recent fault history.

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Why Choose APS Automotive

Honest Diagnostics

We tell you exactly what's wrong and what it takes to fix it. Nothing more, nothing less. No upselling, no surprise charges.

Quality Parts & Warranty

We use only trusted brands and back our work with a solid warranty, giving you peace of mind long after you drive away.

Fast Turnaround

We know you need your vehicle. Our efficient workflow gets you back behind the wheel as quickly as possible without cutting corners.

ASE Certified Technicians

Our 2 ASE-certified technicians bring real expertise. We're also California-licensed smog technicians serving Atascadero since 1992.

Transparent Pricing

You'll receive a detailed estimate before we begin any work. We respect your budget and will never start without your approval.

Clear Communication

No confusing jargon. Just straightforward explanations of what your vehicle needs and why. We're educators, not salespeople.

Ready to Schedule Service?

Request an appointment. We're open Monday through Friday, 7:30am – 5:30pm.

(805) 461-5823

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