For 1990-2009 cars only
There are two modes that can be selected with the hand held scanner. The following is a description of each mode and the functions available:
Service Mode
With the hand held scanner connected to the data link connector (DLC) and the Service Mode, or ON selected, the engine control module (ECM) will enter the service mode and the following will occur:
| • | The ECM signals the service mode is entered by displaying diagnostic trouble code (DTC) 12. The ECM does this by flashing the malfunction indicator lamp (MIL) once, pausing, and then flashing the MIL twice. This sequence will continue as long as no other DTCs are present. |
| • | The ECM will display any stored DTCs by flashing the MIL. The DTCs will be displayed twice, and then DTC 12 will be flashed again. |
| • | The ignition timing is controlled to a fixed timing degree programmed in the ECM. This allows base timing to be adjusted on distributor equipped engines. |
| • | The ECM controls the idle air control (IAC) valve to maintain approximately 1,000 RPM. |
Normal Mode
With the hand held scanner connected to the data link connector (DLC) and the Normal Mode, or OFF selected, the engine control module (ECM) will return to normal operation. The hand held scanner has no effect on operation in this mode.
