When I scan the vehicle, it displays NOT READY

The vehicle has not completed its readiness Tests since the last time it was cleared or the battery was disconnected.

It will continue to say “NOT READY” until all on board diagnostic tests have been completed. This does not mean that it is not ready to be scanned. To get to this screen the vehicle computer reported that no Trouble Codes exist.

Some states require that some or all on-board tests be completed and no Trouble Codes be present to pass emissions testing. When the ScanGauge reports No Codes Found and READY, the vehicle is ready to pass emissions. Some states allow some tests to not be completed and can pass the vehicle even when the ScanGauge reports NOT READY.

Unable to clear trouble codes

Sometimes multiple attempts are needed to clear the codes. You may also try clearing the codes with the vehicle not running, and the key in the ON/RUN position.

Some vehicles don’t respond properly to the Clear Codes command and the codes cannot be cleared by the ScanGauge.

When I press SCAN it says -Not Ready- in the lower line. How can I tell which OBD test has not been completed?

There is a way to do this using the CMNDS feature in the ScanGauge II. See Finding Incomplete OBDII Tests Using the ScanGauge II.

What is FRZD in the ScanGauge?

When a trouble code is set, the data at that time (RPM, Coolant Temperature, Speed, Throttle Position, etc.) are captured like in a freeze frame. FRZD can be used to recall this data to help diagnose the problem.

The ScanGauge shows a trouble code of E0468. How do I figure out what this means?

There are many sources to decode this. A search of the internet for Trouble Codes for your particular vehicle is a great way to get them. Print them out and keep them in the car for future reference. You can also find them in the vehicle shop manual and after-market service and emissions manuals.