Home  |  What Does CarMD Test?

The CarMD tester monitors all of the systems throughout the vehicle that are related to on-board diagnostics. This translates into coverage of approximately 80 percent of the vehicle’s systems.

The CarMD device and website are meant to provide a basic overview of probable causes related to engine, electronic and emissions systems in your vehicle. This product should be used as a supplement to a regular automotive maintenance program, which also includes basic mechanical upkeep such as regularly checking your tire pressure, oil and fluids. *


The following is a partial list of systems it monitors and problems that CarMD can catch:

The following is a list of some of the things that CarMD does not monitor:

  • Air Bags / Supplemental Restraint System (SRS) Coming Soon!

  • Air Conditioning A/C Clutch Status

  • Anti-Lock Brake System (ABS)
    Coming Soon!

  • Camshaft Position Sensor 

  • Catalytic Converter(s) Failure

  • Check Engine Light Diagnosis

  • Clutch Position Sensor

  • Comprehensive Component Monitoring System

  • Crankshaft Position Sensor

  • Cruise Control System

  • EGR (Exhaust Gar Recirculation) Valve Problem

  • Engine Control Module Failure

  • Engine Coolant Temperature (ECT)

  • Engine Misfire

  • Engine Oil Monitoring System (If Vehicle Equipped)

  • Engine Speed RPM Input Circuit

  • Evaporative Emissions System Malfunction (EVAP) 

  • Exhaust Gas Recirculation System (EGR)

  • Fuel Injector Control System Failure 

  • Fuel Sending Unit System

  • Fuel Metering System  (Too Rich/Too Lean)

  • Heated Catalyst Monitor System

  • Heated Oxygen Sensor HO2S Circuit

  • Idle Air Control (IAC) Valve Circuit Low Voltage

  • Ignition System Failure

  • Intake Air Control Valve Monitor

  • Intake Air Heater

  • Intake Air Temperature IAT Sensor Circuit High VoltageKnock Control System (Sensor/Circuit)

  • Loose/Missing/Damaged Gas Cap

  • Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

  • Mass Air Flow Circuit/Sensor

  • Non Methane Hydrocarbon (NMHC) Monitor (If Vehicle Equipped)

  • Oxygen Sensor(s) Failure  (Sensor/Circuit)

  • Power Stering Pressure System (Sensor/Circuit)

  • Radiator Fan Control System (FC)

  • Secondary Air Injection System

  • Supercharger & Turbocharger/Boost Sensor Malfunction

  • Thermostat

  • Throttle Position (TP) Sensor/Circuit

  • Torque Converter Clutch

  • Transmission Fluid Monitoring System (If Vehicle Equipped)

  • Transmission Shift Solenoids

  • Vacuum Leak Detection

  • Vehicle Speed Sensor (VSS) system/circuit

(Any mechanical parts)

  • Alarm System

  • Audio/Entertainment System

  • Belts & Hoses

  • Body Damage

  • Brake Pad Wear

  • Door Locks

  • General Fluid Levels

  • Wiper Blades

  • Interior Condition

  • Maintenance History

  • Service Indicator Light (Not to be confused with the "Check Engine" or "Service Engine Soon" light.  The "Service Light" is a courtesy maintenance reminder recommended by the vehicle manufacturer. It is usually tied to vehicle mileage.)

  • Tire Condition

  • Tire Pressure (TPMS)

  • Windows


If you have a question about whether CarMD monitors a specific system or part that you do not see listed above, please send an email to support@CarMD.com.