THEORY OF OPERATION
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Speed Control Switch is hardwired to the Steering Column Control Module (SCCM). The SCCM is located near the top of the steering column below the steering wheel. The SCCM includes the steering column shroud, the Steering Angle Sensor (SAS), the Clockspring, the Multi-function Switch, a Steering Column Power Tilt and Telescope Switch (if equipped), and a trim cover. The speed control messages are bussed to the Powertrain Control Module (PCM) via the Can Bus.
The Powertrain Control module (PCM) uses the generator field duty cycle signal circuit or F-terminal circuit, to monitor the duty cycle of the generator. The generator field duty cycle signal circuit connects to high side of the field windings in the generator. A Pulse Width Modulated (PWM) high side driver in the voltage regulator turns the field windings ON and OFF. The PCM uses the PWM signal input to determine the generator load on the engine. This allows the PCM to adjust the idle speed to compensate for high electrical loads. The PCM monitors the status of the generator field duty cycle signal circuit. When the key is in the RUN position and the engine is OFF, the PCM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5-95 percent.
The Fuel Pump control is requested by the Powertrain Control Module (PCM) along the Fuel Pump control relay circuit. The Totally Integrated Power Module (TIPM) monitors the sense voltage on the Fuel Pump relay circuit, when PCM pulls the circuit low the TIPM engages the Fuel Pump. If the sense voltage is open or pulled low the PCM will set the P0627-FUEL PUMP RELAY CIRCUIT DTC.
The A/C clutch control is requested by the Powertrain Control Module (PCM) along the A/C clutch control relay circuit. The Totally Integrated Power Module (TIPM) monitors the sense voltage on the A/C clutch relay circuit, when PCM pulls the circuit low the TIPM engages the A/C clutch. If the sense voltage is missing or pulled low the PCM will set the P0645-A/C CLUTCH RELAY CIRCUIT DTC.
For information regarding ASD relay description and operation. Refer to RELAY, AUTO SHUT DOWN, DESCRIPTION .
For specific relay location and type. Refer to FUSE LOCATIONS AND TYPES, SPECIFICATIONS .
For information for ASD relay description and operation. Refer to RELAY, AUTO SHUT DOWN, DESCRIPTION .
For specific relay location and type. Refer to FUSE LOCATIONS AND TYPES, SPECIFICATIONS .
The engine oil pump features seven vanes and a moving element that continuously adjusts to maintain a regulated oil pressure supply by varying the displacement of the pump. The pump has two regulated pressure stages of operation controlled by an on/off solenoid. Low pressure mode regulation (solenoid on) is approximately 200 kPa (29 psi) and high pressure mode regulation (solenoid off) is approximately 450 kPa (65 psi). The Powertrain Control Module (PCM) switches the pump between stages based on engine operating conditions, oil and coolant temperatures, speed and load. Under most typical conditions, the pump will run in low mode from idle up to around 3000 RPM and switch from low to high mode between 3000 and 4000 RPM. The maximum oil pressure in the engine is limited to 1000 kPa (145 psi) by the relief valve. Pressure in the main oil gallery of the engine can be monitored with diagnostic equipment through the oil pressure sensor mounted on the rear of the oil filter module. The minimum pressure for the engine is 41 kPa (6 psi) at any operating condition. Anything under this pressure could result in damage to critical moving parts.
The engine oil pump features seven vanes and a moving element that continuously adjusts to maintain a regulated oil pressure supply by varying the displacement of the pump. The pump has two regulated pressure stages of operation controlled by an on/off solenoid. Low pressure mode regulation (solenoid on) is approximately 200 kPa (29 psi) and high pressure mode regulation (solenoid off) is approximately 450 kPa (65 psi). The Powertrain Control Module (PCM) switches the pump between stages based on engine operating conditions, oil and coolant temperatures, speed and load. Under most typical conditions, the pump will run in low mode from idle up to around 3000 RPM and switch from low to high mode between 3000 and 4000 RPM. The maximum oil pressure in the engine is limited to 1000 kPa (145 psi) by the relief valve. Pressure in the main oil gallery of the engine can be monitored with diagnostic equipment through the oil pressure sensor mounted on the rear of the oil filter module. The minimum pressure for the engine is 41 kPa (6 psi) at any operating condition. Anything under this pressure could result in damage to critical moving parts.
The engine oil pump features seven vanes and a moving element that continuously adjusts to maintain a regulated oil pressure supply by varying the displacement of the pump. The pump has two regulated pressure stages of operation controlled by an on/off solenoid. Low pressure mode regulation (solenoid on) is approximately 200 kPa (29 psi) and high pressure mode regulation (solenoid off) is approximately 450 kPa (65 psi). The Powertrain Control Module (PCM) switches the pump between stages based on engine operating conditions, oil and coolant temperatures, speed and load. Under most typical conditions, the pump will run in low mode from idle up to around 3000 RPM and switch from low to high mode between 3000 and 4000 RPM. The maximum oil pressure in the engine is limited to 1000 kPa (145 psi) by the relief valve. Pressure in the main oil gallery of the engine can be monitored with diagnostic equipment through the oil pressure sensor mounted on the rear of the oil filter module. The minimum pressure for the engine is 41 kPa (6 psi) at any operating condition. Anything under this pressure could result in damage to critical moving parts.
for further information. Refer to SWITCH, STOP LAMP, DESCRIPTION .
The Park Neutral switch rationality test is enabled only for vehicles equipped with a 4/5 speed automatic transmission. This diagnostic checks if the park/neutral switch is incorrectly stuck in the neutral position during driving conditions by comparing Vehicle Speed, Engine Speed, Throttle Position and Pressure Ratio to the fail thresholds and by looking at the state of the Park/Neutral Switch. The stuck in drive condition is not explicitly checked as the starter relay does not energize and therefore render the vehicle inoperable.
The General Temperature Rationality looks at the outputs of the three temperature sensors and compare them under cold start conditions. Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors will be compared. If two sensors agree but not the third, the third sensor is declared as irrational. If all three sensors are irrational the General Temperature Sensor Rationality is failed.
For an aged O2 sensor, the response rate to the air/fuel change is slower than when it was new. The O2 sensor tends to move less with the same air/fuel changes in a given time frame. Therefore by observing the activity of voltage readings from the upstream O2 sensor, the quality of the O2 sensor can be detected. DTCs P113D and P113E are used to validate the high frequency switching of the O2 sensor for DTCs P219A and P219B.
For an aged O2 sensor, the response rate to the air/fuel change is slower than when it was new. The O2 sensor tends to move less with the same air/fuel changes in a given time frame. Therefore by observing the activity of voltage readings from the upstream O2 sensor, the quality of the O2 sensor can be detected. DTCs P113D and P113E are used to validate the high frequency switching of the O2 sensor for DTCs P219A and P219B.
When all criteria has been met, power is supplied to each Multiple Displacement System (MDS) solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.
When all criteria has been met, power is supplied to each Multiple Displacement System (MDS) solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.
When all criteria has been met, power is supplied to each Multiple Displacement System (MDS) solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.
When all criteria has been met, power is supplied to each Multiple Displacement System (MDS) solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.
For information regarding engine oil. Refer to CAPACITIES AND RECOMMENDED FLUIDS .
For the Variable Camshaft Timing (VCT) to enable, the oil pressure has to be approximately 42 psi. For the VCT to remain enabled the engine oil pressure can not drop below 31 psi.
for further information. Refer to SWITCH, STOP LAMP, DESCRIPTION .