Comprehensive Component Monitoring
Comprehensive Component MonitoringComprehensive component monitoring diagnostics are required to monitor emissions-related Input and Output powertrain components. The California Air Resources Board (CARB) OBD II Comprehensive Component Monitoring List Of Components Intended To Illuminate The Malfunction Indicator Lamp (MIL) is a list of components, features or functions that could fall under this requirement.
Input Components
Input components are monitored for circuit continuity and out-of-range values. This includes rationality checking. Rationality 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). Input components may include, but are not limited to the following sensors:
^ Vehicle Speed Sensor (VSS)
^ 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
Output components are diagnosed for proper response to control module 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
^ Control module controlled EVAP Canister Purge Valve
^ Electronic Transaxle controls
^ A/C relay
^ Cooling fan relay
^ VSS output
^ MIL control
^ Cruise control inhibit
Description:
California Air Resources Board (CARB) OBD II Comprehensive Component Monitoring List of Components Intended to Illuminate MIL
Important: Not all vehicles have these components.
Wiring Service
Wiring Harness
The control module harness electrically connects the control module to the various solenoids, switches, and sensors in the vehicle engine room and passenger compartment.
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.
For wiring repair, refer to Wiring Repairs.
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 the Weather-Pack seals. Use the tachometer adapter J 35812, or the equivalent, which provides a convenient connection to the tachometer lead. The connector test adapter kit J 35616, or the equivalent, contains an assortment of flexible connectors used in order to probe the terminals during the diagnosis. The fuse remover and the test tool BT-8616, or the equivalent, is used for removing a fuse and to adapt the fuse holder to a meter 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 Com-Pack Ill terminals look similar, but are serviced differently.