Comprehensive Component Monitoring
COMPREHENSIVE COMPONENT MONITOR DIAGNOSTICComprehensive component monitoring diagnostics are required to monitor emissions-related input and output Powertrain components.
INPUT COMPONENTS
The PCM monitors the input components for circuit continuity and out-of-range values. This includes performance checking. Performance checking refers to indicating a fault when the signal from a sensor does not seem reasonable (i.e. a Throttle Position (TP) sensor that indicates high throttle position at low engine loads or MAP voltage). The input components may include but are not limited to the following sensors:
^ The Vehicle Speed (VSS) sensor
^ The Accelerator Pedal Position (APP) sensor (if so equipped)
^ Mass Air Flow (MAF) sensor
^ Intake Air Temperature (IAT) sensor
^ Crankshaft Position (CKP) sensor
^ Knock Sensor (KS)
^ Throttle Position (TP) sensor
^ Engine Coolant Temperature (ECT) sensor
^ Camshaft Position (CMP) sensor
^ Manifold Absolute Pressure (MAP) sensor
^ Mass Air Flow (MAF) sensor
In addition to the circuit continuity and rationality check, the ECT sensor is monitored for its ability to achieve a steady state temperature to enable closed loop fuel control.
OUTPUT COMPONENTS
Diagnose the output components for the proper response to PCM commands. Components where functional monitoring is not feasible will be monitored for circuit continuity and out-of-range values if applicable. Output components to be monitored include, but are not limited to the following circuits:
^ Idle Air Control (IAC) Motor
^ EVAP system
^ Electronic transmission controls
^ A/C relay
^ Cooling fan relay
^ VSS output
^ MIL control
^ Cruise control inhibit (if so equipped)
WIRING HARNESS SERVICE
Replace the wire harnesses with the proper part number replacement. When splicing signal wires into a harness, use the wiring that has high temperature insulation. Consider the low amperage and voltage levels utilized in the Powertrain control systems. Make the best possible bond at all splices. Use rosin-core solder in these areas. Molded-on connectors require complete replacement of the connector. Splice a new connector into the harness. Replacement connectors and terminals are listed in Group 8.965 in the Standard Parts Catalog.
CONNECTORS AND TERMINALS
In order to prevent shorting between opposite terminals, use care when probing a connector and when replacing terminals. Damage to the components could result. Always use jumper wires between connectors for circuit checking. Never probe through Weather-Pack seals. The connector test adapter kit J 35616, or the equivalent, contains an assortment of flexible connectors used to probe terminals during diagnosis. Fuse remover and test tool BT-8616, or the equivalent, is used for removing a fuse and to adapt the fuse holder to a DVM for diagnosis.
Open circuits are often difficult to locate by sight because oxidation or terminal misalignment are hidden by the connectors. Merely wiggling a connector on a sensor, or in the wiring harness may temporarily correct the open circuit. Oxidized or loose connections may cause intermittent problems. Be certain the type of connector and terminal before making any connector or terminal repair. Weather-Pack and Corn-Pack III terminals look similar, but are serviced differently.