Powertrain Management: Description and Operation

CONTROL MODULE FUNCTION
The Control Module supplies a buffered voltage to various sensors and switches. The input and output devices in the control module include an analog to digital converters, signal buffers, counters, and special drivers. The Control Module controls most components with electronic switches which complete a ground circuit when turned ON. These switches are arranged in groups of 4 and 7 called one of the following:

^ Quad Driver Module
^ Output Driver Modules

The surface mounted Quad Driver Module can independently control up to 4 outputs (Control Module) terminals. The Output Driver Modules can independently control up to 7 outputs. Not all outputs are always used.

SERVICE ENGINE SOON Malfunction Indicator Lamp (MIL)
The SERVICE ENGINE SOON Malfunction Indicator Lamp (MIL) is located in the Instrument Panel Cluster (IPC). The SERVICE ENGINE SOON MIL is controlled by the PCM through CKT 419 and is used to indicate that the PCM has detected a problem that affects vehicle emissions, may cause powertrain damage, or severely impacts driveability. Refer to DTC P1641 for diagnosis of Service Engine Soon MIL. Testing and Inspection

AFTER DIAGNOSIS IS COMPLETE
After diagnosing a problem, in addition to repairing the discovered fault, it is a good idea to clear any DTC(s) set and verify proper operation. To verify a repair, you must duplicate the conditions when the customers complaint occurred or if a DTC was set, you must duplicate the test conditions for that DTC and see if the DTC sets. If the DTC runs and passes, chances are good that the problem is repaired.

DTC(s)
DTC(s), when set, indicate that the PCM has detected a malfunction in a particular circuit or system. The PCM is programmed with routines or checks that it follows only under prescribed conditions (called Test Conditions). When these conditions exist, the PCM checks certain circuits or systems for a malfunction. These checks are called failure conditions. When the failure conditions are true, a DTC is set. Some DTC(s) alert the driver through the SERVICE ENGINE SOON MIL or a message. Other DTC(s) don't trigger a driver warning. The PCM also saves data and input parameters when most DTC(s) are set.

UNLEADED EXPORT VEHICLE DTC TYPE INFORMATION
The service information contained in this section refers to the domestic calibration package - United States, Puerto Rico, U.S. Virgin Islands, Caribbean and Guam. The Canadian and Unleaded Export calibration package (K 29) is referenced in this section in the DTC Type Table only. For the Unleaded Export calibration package some DTCs have been disabled and others have changed types (Type A to Type D, etc.). If a DTC has changed type or is disabled for the Unleaded Export calibration package, this change is NOT reflected in the service information on the DTCs diagnostic support information. The Unleaded Export calibration package consists of vehicles sold in: Canada, Asia, Korea, Taiwan, Japan, Europe, Israel, Mexico, Iceland, South and Central America and Fleet(Govt./Military).