Grand Cherokee 2WD V8-318 5.2L VIN Y MFI (1994)
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Intake air temperature (IAT) sensor
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Crankshaft position (CKP) sensor
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Throttle Position Sensor (TPS)
Based On These Inputs The PCM Will:
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Adjust engine idle speed through the IAC motor.
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Adjust ignition timing.
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Operate A/C Compressor Clutch relay (if selected).
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Ignore oxygen sensor input. The PCM will enter fuel cut-off strategy (under hard deceleration).
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Determine proper injector pulse width and continue injection (under normal deceleration).
Engine Start-Up
This is an OPEN LOOP mode.
When the starter motor is engaged, the PCM receives input from:
- Battery voltage
- Crankshaft position (CKP) sensor
- Engine coolant temperature (ECT) sensor
- Intake air temperature (IAT) sensor
- Throttle position sensor (TPS)
- Camshaft position (CMP) sensor
- Starter relay
Based on these inputs the PCM will:
- Monitor crankshaft position sensor. If no signal is received within 3 seconds, the PCM will shut down the fuel injection system.
- Supply the injectors with a ground path, firing all injectors until the PCM determines crankshaft position.
- Determine proper ignition timing.
Engine Warm-Up
This is an OPEN LOOP mode.
During engine warm-up, the Powertrain Control Module (PCM) receives input from:
- Battery voltage
- Crankshaft position (CKP) sensor
- Engine coolant temperature (ECT) sensor
- Intake air temperature (IAT) sensor
- Manifold absolute pressure (MAP) sensor
- Throttle position sensor (TPS)
- Camshaft position (CMP) sensor
- A/C select switch
Based on these inputs the PCM will:
- Apply voltage to the injectors. The PCM then controls injection sequence and pulse width by switching individual injector ground paths on
and off.