Information Sensors/Switches
3X REFERENCE PCM INPUTThe PCM uses this signal to calculate engine RPM and crankshaft position at engine speeds above 1200 RPM.Description and Operation
18X REFERENCE PCM INPUT
The PCM uses this signal to calculate engine RPM and crankshaft position at engine speeds below 1200 RPM.Description and Operation
A/C REFRIGERANT PRESSURE SENSOR
The PCM uses this information to adjust the idle air control valve to compensate for the higher engine loads present with high A/C refrigerant pressures and to control the cooling fans.Description and Operation
A/C REQUEST PCM INPUT
The PCM uses this information to adjust the idle speed before turning ON the A/C clutch.Description and Operation
CRANKSHAFT POSITION (CKP) SENSOR
The crankshaft position sensor provides a signal used by the ignition control module to calculate ignition sequence. The ignition control module also uses the crankshaft position sensor signals to initiate 18X and 3X reference pulses which the PCM uses as reference to calculate RPM and crankshaft position.Description and Operation
CAMSHAFT POSITION (CMP) SENSOR AND CAM SIGNAL
The camshaft position sensor sends a cam signal to the PCM which uses it as a sync pulse to trigger the injectors in proper sequence.Description and Operation
ELECTRONIC BRAKE CONTROL MODULE (EBCM) - PCM SERIAL DATA (CKT 800)
The PCM uses the serial data line (CKT 800) to communicate with various other components and systems within the vehicle. The PCM receives rough road information from the EBCM on the serial data circuit (CKT 800). The PCM uses the rough road information to enhance the misfire diagnostic by detecting crankshaft speed variations caused by driving on rough road surfaces. This allows false misfire information to be rejected.
The EBTCM 1 EBCM calculates rough road information by monitoring the ABS wheel speed sensors. If a fault occurs which causes the PCM to not receive rough road information while a misfire DTC is requesting the MIL, DTC P1381 will set.
ENGINE COOLANT TEMPERATURE SENSOR
Engine coolant temperature affects most systems the PCM controls.
EGR PINTLE POSITION SENSOR
The PCM monitors the EGR valve pintle position input to ensure that the valve responds properly to commands from the PCM and to detect a fault if the pintle position sensor and control circuits are open or shorted.Description and Operation
EVAP VACUUM SWITCH
The EVAP Vacuum Switch is used by the PCM to monitor EVAP canister purge solenoid operation and purge system integrity.Description and Operation
FUEL CONTROL HEATED OXYGEN SENSORS
The Bank 1 HO2S 2 sensor produces an output signal which indicates the amount of oxygen present in the exhaust gas entering the three-way catalytic converter. The Bank 1 HO2S 3 sensor produces an output signal which indicates the oxygen storage capacity of the catalyst; this in turn indicates the catalyst's ability to convert exhaust gases efficiently. If the catalyst is operating efficiently, the Bank 1 HO2S 2 signal will be far more active than that produced by the Bank 1 HO2S 3 sensor.Description and Operation
INTAKE AIR TEMPERATURE (IAT) SENSOR
The IAT sensor signal is used to adjust spark timing according to incoming air density.Description and Operation
KNOCK SENSORS
The knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The sensor produces an AC output voltage which increases with the severity of the knock. This signal voltage inputs to the Powertrain Control Module (PCM). The PCM then adjusts Ignition Control (IC) timing to reduce spark knock.Description and Operation
THE MASS AIR FLOW (MAF) SENSOR
The Mass Air Flow (MAF) sensor measures the amount of air which passes through the throttle body. The PCM uses this information to determine the operating condition of the engine, to control fuel delivery.Description and Operation
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum).Description and Operation
TCC BRAKE SWITCH
The TCC brake switch signal indicates when the brake pedal is applied. The TCC brake switch information is used by the PCM mainly to control the transmission torque converter clutch.
TRANSMISSION TEMPERATURE SENSOR
The transmission fluid temperature sensor is a thermistor which changes value based on the temperature of the transmission fluid.
THROTTLE POSITION (TP) SENSOR
The Throttle Position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the PCM calculates throttle position.Description and Operation