READING OBD2 FAULT CODES
Enter OBD2
OBD2 is more user-friendly. All manufacturers switched to a standard protocol and 16-pin socket. Cheap scanners can by linked via Bluetooth to a smartphone or tablet. You can also read codes on a laptop using a cable and appropriate software.
Diagnosing faults
When the scan is complete, the screen shows stored fault codes as a list of four digit numbers with a brief text description. Usually looking up the code online or in a workshop manual will provide more details about the fault – and the likely cures.
Checking components
A multimeter can often be used to test a suspect sensor. This Jaguar’s coolant temperature sensor is tested by measuring the resistance across its pins at different temperatures. The correct resistances at set temperatures can be found online.
Plugging in
OCD2 ports are usually located inside the car, generally under the dash. This Jaguar has its port in the driver’s footwell. Plug a Bluetooth scanner or USB cable into the port and connect your phone, tablet or laptop. The scanner gets its power from the port.
Finding more information
Some devices are quite clever. The software of our scanner automatically looks up the car manufacturer’s fault code information if the tablet is connected to Wifi. This provides useful information on how to fix the fault – in this case an ECU error.
Clearing fault codes
Once you’ve solved the issue, select the option to clear the codes stored in the ECU from the scanner’s menu. This can take some time. The codes should eventually disappear and the engine management light on the dash should go out.
Reading OBD2 codes
Turn on your device and launch the software. The exact appearance will of the user interface will depend on what you’re using. Select the option to read stored fault codes. It usually takes a minute-or-two before they’re displayed on the screen.
Viewing live readings
Scanners can display live readings from the main sensors, which is useful to check if they’re functioning sensibly. For example, you can test the throttle position sensor by watching how the throttle dial changes while pressing the pedal.
Service indicator
Obd2-equipped cars also have a dashboard service indicator. This is usually reset without the scanner by simultaneously pressing dashboard control buttons in a sequence. The method varies: check online or in your workshop manual.