Van wont start

  • 6 CYL
  • FWD
  • 135,847 MILES
I was told I need a computer wat is a computer and wat is the retail price for one
Do you
have the same problem?
Saturday, February 12th, 2011 AT 4:57 AM

1 Reply

The PCM is a digital computer containing a microprocessor.

The PCM receives input signals from various switches and sensors that are referred to as PCM Inputs. Based on these inputs, the PCM adjusts various engine and vehicle operations through devices that are referred to as PCM Outputs.

PCM Inputs

Air Conditioning Head Pressure
Battery Voltage
Brake Switch
Camshaft Position Sensor
Crankshaft Position Sensor
Engine Coolant Temperature Sensor
Heated Oxygen Sensors (Upstream and Downstream)
Manifold Absolute Pressure (MAP) Sensor
SCI Receive
Speed Control System Controls
Throttle Position Sensor
Transaxle Park/Neutral Position Switch (automatic transaxle)
Transmission Control Module
Vehicle Speed Sensor
PCM Outputs

Air Conditioning Clutch Relay
Automatic Shutdown (ASD) Relay
Data Link Connector
Proportional Purge Solenoid
Electric EGR Transducer
Fuel Injectors
Fuel Pump Relay
Generator Field
Idle Air Control Motor
Ignition Coil
Leak Detection Pump
Malfunction Indicator (Check Engine) Lamp
Radiator Fan Control Module
Speed Control Solenoids
Tachometer Output
Torque Converter Clutch Solenoid (3 speed transmission)
Transmission Control Module
Based on inputs it receives, the PCM adjusts fuel injector pulse width, idle speed, ignition spark advance, ignition coil dwell and canister purge operation. The PCM regulates the cooling fan, air conditioning and speed control systems. The PCM changes generator charge rate by adjusting the generator field.

The PCM adjusts injector pulse width (air/fuel ratio) based on the following inputs:

Battery voltage
Engine coolant temperature
Exhaust gas content (oxygen sensors)
Engine speed (crankshaft position sensor)
Manifold absolute pressure
Throttle position
The PCM adjusts ignition timing based on the following inputs.

Barometric pressure
Engine coolant temperature
Engine speed (crankshaft position sensor)
Manifold absolute pressure
Throttle position
Transaxle gear selection (park/neutral switch)
The PCM also adjusts engine idle speed through the idle air control motor based on the following inputs.

Air conditioning select switch head pressure
Brake switch
Engine coolant temperature
Engine speed (crankshaft position sensor)
Manifold absolute pressure
Throttle position
Transaxle gear selection (park/neutral switch)
Vehicle distance (speed)
The Automatic Shutdown (ASD) and fuel pump relays are located in the Power Distribution Center (PDC).

The camshaft position sensor (distributor pick-up signal) and crankshaft position sensor signals are sent to the PCM. If the PCM does not receive both signals within approximately one second of engine cranking, it deactivates the ASD relay and fuel pump relay. When these relays are deactivated, power is shut off to the fuel injectors, ignition coil, oxygen sensor heating element and fuel pump.

The PCM contains a voltage converter that changes battery voltage to a regulated 8.0 volts to power the Camshaft Position Sensor, Crankshaft Position Sensor and Vehicle Speed Sensor. The PCM also provides a 5.0 volt supply for the Manifold Absolute Pressure Sensor, Throttle Position Sensor and Engine Coolant Temperature Sensor.

See price below:Note-Part and labor varies within location.
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Monday, March 28th, 2011 AT 2:54 AM

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