In process of controlling various subsystems, PCM, DERM, EBTCM, RSS Module and BCM continually monitor operating conditions for possible system malfunctions. By comparing system conditions against standard operating limits, certain circuit and component malfunctions can be detected. A three digit numerical Trouble Code is stored in computer memory when a problem is detected by this self-diagnostic system.

These trouble codes can later be displayed as an aid in system repair. The occurrence of certain system malfunctions require that vehicle operator be alerted to problem so as to avoid prolonged operation of vehicle under subnormal system operation. Computer controlled diagnostic messages and/or telltales will appear under these conditions which indicate that service is required.

If a particular malfunction would result in unacceptable system operation, self-diagnostics will attempt to minimize effect by taking "Failsoft" action. Failsoft action refers to any specific attempt by computer system to compensate for the detected problem. A typical "Failsoft" action would be a situation of a fixed input value when a sensor is detected to be open or shorted.

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

Trouble Codes

Use the Manual With the Right Hardware

When to See a Mechanic