What Info Can an OBD2 Scanner Tell Me?

OBD2 scanners are invaluable tools when it comes to diagnosing and subsequently repairing a vehicle. The assortment of information they can unearth is enormous and extremely useful, providing particulars that ultimately aid in a fix. What follows is some of what an OBD2 scanner can provide:

Diagnostic Trouble Codes (DTCs): OBD2 scanners can read and interpret DTCs, which are codes that indicate issues within the vehicle's systems. These codes can help identify specific problems that may be affecting the engine, transmission, emissions, and other components. DTC has come to be the generic acronym used for the codes that a scanner pulls, so don’t be surprised to hear this used interchangeably throughout conversations surrounding the diagnosis of a vehicle’s problems.

Check Engine Light (CEL) Status: The CEL is the illuminated symbol of doom for some, but its appearance doesn’t tell even the start of the story. An OBD2 scanner can check the status of the check engine light and provide information about the specific issue triggering the light, helping make sense of what might be mysterious.

Live Data: Some OBD2 scanners can display real-time data from sensors and systems in the vehicle. This may include information such as engine RPM, coolant temperature, vehicle speed, oxygen sensor readings, and more. We’re particularly fond of the OBD2 scanners that display things like transmission temperature, which is a vital thing to monitor when towing or off-roading.

Readiness Monitors: OBD2 scanners can show the status of readiness monitors, which are self-tests that the vehicle's emissions control system performs. This information is useful for emissions testing; sometimes when replacing components to help pass an emissions test, the vehicle needs to re-learn the parameters. In order for this to happen, the car may need to be driven a certain number of miles. This number varies, but figure 50 miles at a minimum. An OBD2 scanner can tell when those monitors have hit their readiness threshold, at which point a vehicle can be run back through an emissions test.

Vehicle Information: The scanner can retrieve details about the vehicle, such as its VIN (Vehicle Identification Number), calibration IDs, and calibration verification numbers.

Oxygen Sensor Data: OBD2 scanners can provide data related to the performance of oxygen sensors, helping diagnose issues with fuel efficiency and emissions. This is also helpful in turning performance cars.

Resetting Codes: Some OBD2 scanners allow users to clear diagnostic trouble codes after addressing the underlying issues. However, it's important to note that clearing codes without fixing the problem may-- and likely will-- result in the issues recurring. In some instances though, like a loose gas cap that caused a CEL and didn’t reset itself, clearing the code is likely to be a quick solution.

Vehicle Performance Monitoring: Advanced OBD2 scanners may offer additional features such as performance monitoring, fuel efficiency analysis, and trip data recording. They can provide information on real-time RPM and speed readings, run time after a restart, average speed, and so on.

In terms of the specifics, here are some common types of codes that an OBD2 scanner can supply:

• P-Codes (Powertrain Codes):
• P0xxx: Generic powertrain codes
• P1xxx: Manufacturer-specific powertrain codes

• B-Codes (Body Codes):
• B0xxx: Generic body codes
• B1xxx: Manufacturer-specific body codes

• C-Codes (Chassis Codes):
• C0xxx: Generic chassis codes
• C1xxx: Manufacturer-specific chassis codes

• U-Codes (Network Communication Codes):
• U0xxx: Generic network communication codes
• U1xxx: Manufacturer-specific network communication codes

It's important to note that while OBD2 scanners can provide valuable information about potential issues, they do not necessarily pinpoint the exact cause of a problem. Additional diagnostics and expertise may be needed to address and resolve specific issues with your vehicle.