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3.0L MULTI-PORT FUEL INJECTION—SYSTEM OPERATION INDEX page page Air Conditioning (A/C) Clutch Relay (AA, AG, AJ Body)—PCM Output . . . . . . . . . . . . . . . . . . . . 118 Air Conditioning (A/C) Clutch Relay (AC Body) —PCM Output . . . . . . . . . . . . . . . . . . . . . . . . 118 Air Conditioning Switch Sense (AA, AG, AJ Body)—PCM Input . . . . . . . . . . . . . . . . . . . . . 115 Air Conditioning Switch Sense (AC Body)—PCM Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Auto Shutdown (ASD) Relay and Fuel Pump Relay—PCM Output . . . . . . . . . . . . . . . . . . . . 119 Battery Voltage—PCM Input . . . . . . . . . . . . . . . 115 Brake Switch—PCM Input . . . . . . . . . . . . . . . . . 115 CCD Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Data Link Connector—PCM Output . . . . . . . . . . 120 Distributor Pick-Up—PCM Input . . . . . . . . . . . . . 115 Duty Cycle Evap Canister Purge Solenoid —PCM Output . . . . . . . . . . . . . . . . . . . . . . . . 119 Engine Coolant Temperature Sensor —PCM Input . . . . . . . . . . . . . . . . . . . . . . . . . 115 Fuel Injectors—PCM Output . . . . . . . . . . . . . . . 120 Fuel Pressure Regulator . . . . . . . . . . . . . . . . . . 124 Fuel Supply Circuit . . . . . . . . . . . . . . . . . . . . . . 123 General Information . . . . . . . . . . . . . . . . . . . . . . 113 Generator Field—PCM Output . . . . . . . . . . . . . . 118 Heated Oxygen Sensor (O 2 Sensor) —PCM Input . . . . . . . . . . . . . . . . . . . . . . . . . 116 Idle Air Control Motor—PCM Output . . . . . . . . . 119 Ignition Coil—PCM Output . . . . . . . . . . . . . . . . . 121 Malfunction Indicator Lamp (Check Engine Lamp)—PCM Output . . . . . . . . . . . . . . . . . . . 120 Manifold Absolute Pressure (MAP) Sensor —PCM Input . . . . . . . . . . . . . . . . . . . . . . . . . 116 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . 121 Park/Neutral Switch—PCM Input . . . . . . . . . . . . 117 Part Throttle Unlock Solenoid—PCM Output . . . 121 Powertrain Control Module . . . . . . . . . . . . . . . . . 113 Radiator Fan Relay—PCM Output . . . . . . . . . . . 121 Speed Control Solenoids—PCM Output . . . . . . . 121 Speed Control—PCM Input . . . . . . . . . . . . . . . . 117 System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . 113 Tachometer—PCM Output . . . . . . . . . . . . . . . . . 121 Throttle Body . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Throttle Position Sensor (TPS)—PCM Input . . . . 117 Transaxle Control Module—PCM Output . . . . . . 120 Vehicle Speed and Distance Input—PCM Input . 118 Vehicle Speed Sensor—PCM Input . . . . . . . . . . 118 GENERAL INFORMATION The 3.0L engine uses a sequential Multi-Port Elec- tronic Fuel Injection system (Fig. 1). The MPI system The MPI system is operated by the powertrain con- trol module (PCM). The PCM regulates ignition timing, air-fuel ratio, emission control devices, cooling fan, charging sys- All inputs to the PCM are converted into signals. The PCM can adapt its programming to meet chang- Fuel is injected into the intake port above the in- take valve in precise metered amounts through elec- operated injectors. The PCM fires the injectors in a specific sequence. The PCM maintains The PCM adjusts injector pulse width by opening and closing the ground path to the injector. Engine SYSTEM DIAGNOSIS The powertrain control module (PCM) tests many of its own input and output circuits. If a fault is CCD BUS Various modules exchange information through a communications port called the CCD Bus. The pow- POWERTRAIN CONTROL MODULE The powertrain control module (PCM) is a digital computer containing a microprocessor (Fig. 2). The PCM Inputs: • Air Conditioning Controls • Battery Voltage • Brake Switch Ä FUEL SYSTEMS 14 - 113 |