OBD-II data streams are prioritized. When 2 messages attempt to establish communications on a data line at the same time, only the message with higher priority will continue. A new segment of the software called the Diagnostic Executive coordinates the protocol for recording and displaying diagnostic procedures.

Diagnostic Executive is a unique segment of software which is designed to coordinate and prioritize diagnostic procedures as well as define protocol for recording and displaying their results. The main responsibilities of the Diagnostic Executive are as follows:

Commanding CHECK ENGINE lamp on and off.
DTC logging and clearing.
Freeze Frame data for the first emission related DTC recorded.
Non-emission related service lamp.
Operating conditions Failure Records buffer, (the number of records will vary).
Current status information on each diagnostic.
System status (I/M ready).

Diagnostic Executive records DTCs and turns on MIL when emission-related faults occur. It can also turn off MIL if conditions cease which caused DTC to set.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Diagnostic Executive

Use the Manual With the Right Hardware

When to See a Mechanic

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