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OBD-II scanning reads the trouble codes and live data stored in your vehicle's computers through the diagnostic port under the dash. Route 66 Auto Repair in Upland scans every module we can reach, including body, lighting, door and network modules that a basic engine-only reader cannot see. Our ASE-certified technicians use the scan as the first step of an electrical diagnosis and explain what the codes do and do not prove.
What does a full scan show that a basic reader does not?
- Body control codes for lights, locks and windows
- Network codes (U codes) when modules stop communicating
- Airbag, ABS and climate module codes
- Freeze frame data showing conditions when a code set
- Readiness monitor status after a repair or battery disconnect
What can a scan not tell you?
A code points to a circuit or a condition a module did not like. It does not prove a part is bad. A low voltage code may come from a failing battery, a bad ground or a weak alternator. That is why a scan is followed by testing, such as electrical system testing.
Some faults leave no code at all, such as a dead dome light on a simple circuit. Some modules need brand-specific software to read, and any module programming needs are confirmed on the estimate. For a hybrid, tell us it is a hybrid at intake and we will explain what we can take on. The NHTSA recall lookup (opens in a new tab) is worth checking too, since some electrical faults are recall items.
Our scanning process
Step 1: Connect and identify
The scan tool connects at the diagnostic port and confirms the vehicle and its modules.
Step 2: Read every module
Codes, status and freeze frame are collected from each reachable module.
Step 3: Sort the results
We separate current faults from old history and group codes that share a cause.
Step 4: Explain next steps
You get the codes in plain language and a recommendation for testing or repair.
What's included in an OBD-II scan
Included on the work order
- 01Scan of all reachable modules
- 02Current and history code list
- 03Freeze frame data review
- 04Readiness monitor status
- 05Plain-language explanation and next-step recommendation
How do we label scan findings?
Need now: call
- Active codes for charging, airbags, ABS or engine control
- Network codes with running or starting problems
- Codes tied to a flashing check engine light
Need later: book
- History codes from a past low battery
- A body code for a feature that still works
- An incomplete monitor after a recent battery change
How pricing and timing work
A scan is quick, and the service writer states the price at the counter before we connect. If you choose testing next, the diagnostic fee is also stated before we start and applies to approved related repair. Repairs are quoted in writing. AAA members save 10% on parts and labor, up to $75, with the card. Scans usually happen while you wait when the board allows; call before you drive over.
After the scan
Do not clear codes before your visit; the history helps us. If a light came on and went off, tell the service writer. For engine-specific trouble, see check engine light diagnostics, and for the scan report format, the OBD-II scan report page. Call (909) 608-7699 with questions.
Frequently asked questions
The parts store read my codes for nothing. Why pay for a scan?
A basic reader usually sees engine codes only. Our scan reads body, network, airbag and ABS modules, and a technician interprets the results. That is often where electrical faults show up.
Can a scan find a battery drain?
Sometimes a module logs a fault that hints at it, but a drain needs a parasitic draw test. The scan helps us decide where to look.
Will the scan erase my codes?
No. We read and record everything first. Codes are cleared only after a repair, and only when you approve it. See check engine light reset.