Electronic Control Modules - Service Information: Overview Dodge Challenger III рестайлинг

DESCRIPTION

The primary on-board communication network between the microprocessor-based Electronic Control Modules (ECMs) in this vehicle is the Controller Area Network (CAN) data bus system. A data bus network minimizes redundant wiring connections; and at the same time, reduces wire harness complexity, sensor current loads and controller hardware by allowing each sensing device to be connected to only one module, (also referred to as a node). Each node reads, then broadcasts its sensor data over the bus for use by all other nodes requiring that data. Each node ignores the messages on the bus that it cannot use.

The CAN bus is a two-wire multiplex system. Multiplexing is any system that enables the transmission of multiple messages over a single channel or circuit. The CAN bus is used for communication between most vehicle nodes. However, in addition to the CAN bus network, certain nodes may also be equipped with a Local Interface Network (LIN) data bus. The LIN data bus is a single wire low-speed (9.6 Kbps) serial link bus used to provide direct communication between a LIN master module and certain switch or sensor inputs.

There are actually three separate CAN bus systems used in the vehicle. They are designated: the CAN-B, the CAN-C and the Diagnostic CAN-C. The CAN-B and CAN-C systems provide on-board communication between all of the nodes that are connected to them. The CAN-C is the faster of the two systems providing near real-time communication (500 Kbps), but is less fault tolerant than the CAN-B system. The CAN-C is used typically for communications between more critical nodes, while the slower (83.3 Kbps), but more fault tolerant CAN-B system is used for communications between less critical nodes. The CAN-B fault tolerance comes from its ability to revert to a single wire communication mode if there is a fault in the bus wiring.

The added speed of the CAN data bus is many times faster than previous data bus systems. This added speed facilitates the addition of more Electronic Control Modules (ECMs) or nodes and the incorporation of many new electrical and electronic features in the vehicle.

The Diagnostic CAN-C bus is also capable of 500 Kbps communication and is sometimes informally referred to as the CAN-D system to differentiate it from the other high speed CAN-C bus. The Diagnostic CAN-C is used exclusively for the transmission of diagnostic information between the Totally Integrated Power Module (TIPM) and a diagnostic scan tool connected to the industry-standard 16-way Data Link Connector (DLC) located beneath the instrument panel on the driver side of the vehicle.

The TIPM is located in the engine compartment near the battery. The central CAN gateway or hub module integral to the TIPM, connects to all three CAN buses. This gateway physically and electrically isolates the CAN buses from each other and coordinates the bi-directional transfer of messages between them.

OPERATION

The Controller Area Network (CAN) data bus allows all electronic modules or nodes connected to the bus to share information with each other. Regardless of whether a message originates from a module on the lower speed CAN-B bus or on the higher speed CAN-C or CAN-D bus, the message structure and layout is similar, which allows the Totally Integrated Power Module (TIPM) to process and transfer messages between the CAN buses. The TIPM also stores a Diagnostic Trouble Code (DTC) for certain bus network faults.

All modules (also referred to as nodes) transmit and receive messages over one of these buses. Data exchange between nodes is achieved by serial transmission of encoded data messages. Each node can both send and receive serial data simultaneously. Each digital bit of a CAN bus messages carries over the bus as a voltage differential between the two bus circuits which, when strung together, form a message. Each node uses arbitration to sort the message priority if two competing messages are attempting to be broadcast at the same time.

The instrument cluster (also known as the Cab Compartment Node/CCN) is the Local Interface Network (LIN) master module in this vehicle and it gathers information from the compass module, the instrument panel switch bank, the Steering Control Module (SCM) and the Heated Seat Module (HSM) through the LIN data bus. There is also LIN bus communication between the individual Tire Pressure Monitor (TPM) transponders and the Wireless Ignition Node (WIN). Both the CCN and the WIN either act directly upon the information received through the LIN data bus, relay the information to other nodes in the vehicle using electronic messages placed on the CAN bus or both.

The voltage network used to transmit messages requires biasing and termination. Each module on the CAN bus network provides its own biasing and termination. There are two types of nodes used in the CAN bus network. On the CAN-C bus, a dominant node has a 120 Ohm termination resistance while a non-dominant (or recessive) node has about a 2500 to 3000 Ohm (2.5 to 3.0 kilohm) termination resistance. The dominant nodes on the CAN-C bus are the WIN and the Powertrain Control Module (PCM).

The termination resistance of the two dominant nodes are combined in parallel to provide a total of about 60 Ohms. This resistance value may vary somewhat by application, depending upon the number of non-dominant nodes on the CAN-C bus. On the CAN-D bus (or Diagnostic CAN-C) all of the 60 Ohm termination resistance is present in the TIPM.

Note. All measurement of termination resistance is done with the vehicle battery disconnected.

Note. Termination resistance of a CAN-B node cannot be verified with a Digital Multi-Meter (DMM) or Digital Volt-Ohm Meter (DVOM). The transceiver of each CAN-B node connects to termination resistors internally. When the vehicle battery is disconnected, the internal connections of all CAN-B node transceivers are switched open, disconnecting the termination resistors. Therefore, the total bus resistance measured under these conditions will be extremely high or infinite, which does not accurately reflect the actual termination resistance of the CAN-B bus.

The communication protocol being used for the CAN data bus is a non-proprietary, open standard adopted from the Bosch CAN Specification 2.0b. The CAN-C is the faster of the two primary buses in the CAN bus system, providing near real-time communication (500 Kbps).

The CAN bus nodes are connected in parallel to the two-wire bus using a twisted pair, where the wires are wrapped around each other to provide shielding from unwanted electromagnetic induction, thus preventing interference with the relatively low voltage signals being carried through them. The twisted pairs have between 33 and 50 twists per meter (yard). While the CAN bus is operating (active), one of the bus wires will carry a higher voltage and is referred to as the CAN High or CAN bus (+) wire, while the other bus wire will carry a lower voltage and is referred to as the CAN Low or CAN bus (-) wire. Refer to the CAN Bus Voltages table.

In order to minimize the potential effects of the Ignition-OFF Draw (IOD), the CAN-B network employs a sleep strategy. However, a network sleep strategy should not be confused with the sleep strategy of the individual nodes on that network, as they may differ. For example: The CAN-C bus network awakes only when the ignition switch is in the ON or START positions; however, the TIPM, which is on the CAN-C bus, may still be awake with the ignition switch in the ACCESSORY or UNLOCK positions. The integrated circuitry of an individual node may be capable of processing certain sensor inputs and outputs without the need to utilize network resources.

The CAN-B bus network remains active until all nodes on that network are ready for sleep. This is determined by the network using tokens in a manner similar to polling. When the last node that is active on the network is ready for sleep and it has already received a token indicating that all other nodes on the bus are ready for sleep, it broadcasts a bus sleep acknowledgment message that causes the network to sleep. Once the CAN-B bus network is asleep, any node on the bus can awaken it by transmitting a message on the network. The TIPM keeps either the CAN-B or the CAN-C bus awake for a timed interval after it receives a diagnostic message for that bus over the Diagnostic CAN-C bus.

In the CAN system, available options are configured into the TIPM at the assembly plant, but additional options can be added in the field using the diagnostic scan tool. The configuration settings are stored in non-volatile memory. The TIPM also has two 64-bit registers, which track each of the as-built and currently responding nodes on the CAN-B and CAN-C buses. The TIPM stores a Diagnostic Trouble Code (DTC) in one of two caches for any detected active or stored faults in the order in which they occur. One cache stores powertrain (P-Code), chassis (C-Code) and body (B-Code) DTCs, while the second cache is dedicated to storing network (U-Code) DTCs.

If there are intermittent or active faults in the CAN network, a diagnostic scan tool connected to the Diagnostic CAN-C bus through the 16-way Data Link Connector (DLC) may only be able to communicate with the TIPM. To aid in CAN network diagnosis, the TIPM provides CAN-B and CAN-C network status information to the scan tool using certain diagnostic signals. In addition, the transceiver in each node on the CAN-C bus will identify a bus off hardware failure , while the transceiver in each node on the CAN-B bus will identify a general bus hardware failure . The transceivers for some CAN-B nodes also identifies certain failures for both CAN-B bus signal wires.

Scheme 1

Vehicles equipped with Active Damping Suspension (ADS) have an Active Damping Control Module (ADCM). The ADCM (1) is located in the left side of the trunk and is retained by three mounting screws (2). The carpet on the left side of the trunk has to be repositioned to access the ADCM.

The Active Damping Control Module (ADCM) uses the CAN bus to communicate with multiple modules. The ADCM has the following inputs: Vehicle Speed, Steering Angle Sensor (SAS) position, Throttle Position Sensor (TPS), Active Damping System (ADS) input switch, and 3 ADS sensors. There are solenoid-controlled ADS valving units on each shock absorber assembly which are the outputs for the ADCM.

The ADS input switch is a momentary switch on the instrument panel switch pod. When the ADS input switch is pressed with the key in the ON or RUN position, a signal is sent over the CAN bus to the ADCM and the Transmission Control Module (TCM) to change modes. The resulting change is indicated in the EVIC.

The Active Damping Control Module (ADCM) controls the suspension and ride for the SRT version of this vehicle by adjusting the rebound and jounce of the shock assemblies using the above information and predetermined settings for maximum vehicle control. The shock absorbers are unique to the Active Damping System (ADS). Each shock absorber has a valving unit that is external, but still part of the shock absorber. Inside each valving unit are two solenoids that control the damping valves to alter the ride of the vehicle. The shocks are replaced as an assembly, they cannot be disassembled for repair.

The two front ADS sensors are mounted with one on each wheel well. The rear ADS sensor is mounted in the right rear wheel well on the shock tower. The ADCM is located in the left side of the trunk.

Two Mode ADS

Early build vehicles with automatic transmissions and all vehicles with manual transmissions have a two mode Active Damping System (ADS), which consists of Auto and Sport Modes. The normal operating mode is Auto, and it is switched to and from Sport with the ADS switch on the instrument panel. When Sport is selected, ADS is activated and there is no change with the transmission programming.

Three Mode ADS

Later vehicles with automatic transmissions have a three mode Active Damping System (ADS), which consists of Auto, Sport, and Track modes. The normal operating mode is Auto, and it is switched to and from Sport or Track with the ADS switch on the instrument panel. If either Sport or Track is active during an ignition on-off-on cycle, the mode reverts to Sport. When Sport is selected, ADS is activated and there is no change with the transmission programming. When Track is selected, ADS and sport shifting in the transmission are activated.

Scheme 2

Note. The Electronic Stability Control (ESC) may also be referred to as Electronic Stability Program (ESP) depending on the vehicle model year and configuration. Certain components may also reference ESP, ESC, or use the traction control symbol.

The Antilock Brake Module (ABM) is a microprocessor-based device which monitors the Antilock Brake System (ABS) during normal braking and controls it when the vehicle is in an ABS stop. The ABM also monitors the Electronic Stability Control (ESC).

The ABM (1) is mounted to the HCU (2) as part of the Integrated Control Unit (ICU). The ABM uses a 47-Way connector on the vehicle wiring harness. The power source for the ABM is through the ignition switch in the RUN or ON position. The ABM is on the CAN-C bus.

Note. The Electronic Stability Control (ESC) may also be referred to as Electronic Stability Program (ESP) depending on the vehicle model year and configuration. Certain components may also reference ESP, ESC, or use the traction control symbol.

The primary functions of the Antilock Brake Module (ABM) are to

1. Monitor the Antilock Brake System (ABS) and Electronic Stability Control (ESC) for proper operation.
2. Detect wheel locking or wheel slipping tendencies by monitoring the speed of all four wheels of the vehicle.
3. Control fluid modulation to the wheel brakes while the system is in ABS or traction control mode.
4. Modulates fluid pressure to the wheel brakes to control vehicle yaw rate in ESC mode.
5. Store diagnostic information.
6. Provide communication to the scan tool while in diagnostic mode.
7. Illuminate the amber TCS/ESC indicator in the instrument cluster.

The ABM constantly monitors the ABS and ESC (if equipped) for proper operation. If the ABM detects a fault, it will turn on the amber TCS/ESC indicator and disable the ABS or ESC if so equipped. The normal base braking system will remain operational at that time.

The ABM continuously monitors the speed of each wheel through the signals generated by the wheel speed sensors to determine if any wheel is beginning to lock. When a wheel locking tendency is detected, the ABM commands the ABM solenoid coils to actuate. The coils then open and close the valves in the HCU that modulate brake fluid pressure in some or all of the hydraulic circuits. The ABM continues to control pressure in individual hydraulic circuits until a locking tendency is no longer present.

The microprocessor-based electronic door control modules (also known as a Driver Door Module/DDM, a Passenger Door Module/PDM, Door Multiplex/MUX Modules or Window Control Modules) contain logic circuits that monitor various hard wired low current, multiplexed inputs from the express up or down (also known as one-touch or auto-up and down) power window switches and motors on their respective door. They also receive Controller Area Network (CAN) data bus electronic message-based external inputs from the opposing front door control module as well as from other electronic modules in the vehicle. The door control modules also monitor hard wired power window motor Hall effect sensor inputs.

The door control modules are powered by a fused B(+) circuit and are grounded at all times so that they can operate regardless of the ignition switch position. The modules are wired to an accessory delay relay, which allows the operation of the windows and for a timed interval after the ignition is turned OFF, provided that the doors are not opened. Both driver and passenger door control modules provide active and stored Diagnostic Trouble Codes (DTC) through On-Board Diagnostics (OBD) and communicate with a diagnostic scan tool using the CAN data bus.

An Anti-Pinch function is a safety feature that senses obstacles at the top of the glass and anywhere on the weather seal where it meets the glass during the window closing operation. When a window switch is pressed to the AUTO position and the closing window traps an object a sense current will surpass its limit, then the module will reverse the power window motor and drive the window down approximately 200 millimeters. The pinch force limit is speed dependent, which means that if the vehicle is going over 2 kilometers per hour the pinch force will be higher than if the vehicle is stationary.

If a power window switch is held in the AUTO position and the closing window traps an object, the module will stop the power window motor and, after the switch is released, will drive the window in the opposite direction approximately 10 millimeters. If the switch is again held in the AUTO position within 8 seconds after the switch was released, the module will enter a Panic mode. During the Panic mode, the module will drive the motor with full (stall) force, then stop.

The hard wired inputs and outputs of the door control module may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication between modules and other devices that provide some features of the power window system features the door control modules provide. The most reliable, efficient and accurate means to diagnose the door control modules or the electronic controls and communication related to operation of these systems requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Scheme 3

1. Disconnect and isolate the battery negative cable.
2. Remove the trim panel from the inside of the front door. Refer to «PANEL, DOOR TRIM, REMOVAL»(ref-489285-S14587999262012072600000) .
3. Disconnect the door wire harness connectors (2) from the door control module (1) connector receptacles.
4. Remove the screws (3) that secure the door control module to the door inner panel.
5. Remove the door control module from the door inner panel.

Multiple modules work together to improve vehicle steering assist at different rates at different speeds. At slow speeds (parking maneuvers) more assist is available and at high speeds less assist is available. The EHPS module uses the CAN - C data bus for inputs and outputs of the information necessary for operation. The use of a scan tool is necessary for diagnostics. EHPS module faults are stored in a diagnostic program memory and are accessible with the scan tool. Faults remain in memory until cleared, or until after the vehicle is started approximately 50 times. Stored faults are not erased if the battery is disconnected. For descriptions and procedures related to DTCs. Refer to DIAGNOSIS AND TESTING .

The Electro-Hydraulic Power Steering (EHPS) Pump assembly contains a control module, brushless electric motor, and hydraulic pump integrated into a single unit. The EHPS Pump draws power from the 12-Volt electrical system and provides the necessary flow and pressure to the steering gear to provide normal power steering. The output flow of the EHPS Pump is varied as a function of Steering Wheel Rate (received from SAS) and Vehicle Speed (received from ABS Module) in order to provide the optimum flow of power steering fluid to the steering gear under all operating conditions. The EHPS Pump will start to provide steering assist when the Vehicle speed message greater than 5 km/h (3 mph) is received on CAN C. If the Vehicle Speed message is missing at vehicle startup, the EHPS Pump will not operate. If the Vehicle Speed message is lost during operation the EHPS pump will use a default vehicle speed of 85 km/h (59 mph) to calculate desired flow and as a result, steering effort will no longer be speed sensitive. If the Steering Wheel Position message is lost the EHPS Pump will use a default steering wheel rate of 230°/sec to calculate desired flow and as a result, steering effort may be higher on evasive steering maneuvers. The EHPS pump will resume normal operation automatically once any missing message or out of range condition noted above is restored to normal.

The Heated Seat Module (HSM), also known as the Comfort Seat Wheel Module (CSWM), controls the heated seat system and the heated steering wheel system, when equipped. The HSM responds to heated seat and steering wheel switch messages and ignition status inputs and controls the 12 volt Direct Current (DC) output to the heating elements through integral solid-state relays.

When either of the front heated seat switches are pressed, a resistive signal is sent to the Cabin Compartment Node (CCN) over hard-wired circuits. The CCN then sends a request signal over the Controller Area Network (CAN) data bus to the HSM, to supply power to the heating elements for the selected seat. When high-level heating is initially selected, the HSM provides a boosted heat level during the first four minutes of operation, then the heat output level drops to normal high setting. When high setting is first selected, the HSM will automatically switch to low-level temperature after approximately thirty minutes of continuous operation. At that time, the number of illuminated indicator lamps in the heated seat switch change from two to one, indicating the temperature level change. Operation on low-level turns off automatically after approximately thirty minutes.

When equipped with a heated steering wheel, pressing the heated steering wheel switch provides a resistive signal over a hard-wired circuits to the CCN. The CCN sends a request signal over the CAN data bus to the HSM, signaling the HSM to power the heating element for the steering wheel.

The heated seat and steering wheel systems operate on battery current received through a fused ignition Run circuit, so that the system will only operate when the engine is running. With a heated seat or steering wheel on, if the ignition is set to any position other than Run, the heated system will turn off, and remain off, until the engine is restarted and a heated seat or steering wheel switch is pressed again.

The HSM is diagnosed using a scan tool and will automatically turn off the heating elements if it detects an open or low short in a heating element circuit. Refer to DIAGNOSIS AND TESTING .

The microprocessor in the Passive Entry Module (PEM) contains the logic circuits and controls all of the features of the Passive Entry (PE) and Keyless Go (KG) systems. The PEM receives battery voltage on a fused B(+) circuit and is grounded at all times through a hard wired remote ground point. These connections allow the PEM to operate regardless of the ignition switch position and with the Ignition-Off Draw (IOD) fuse removed.

The PEM has sufficient driver outputs to power a number of Low Frequency (LF) Radio Frequency (RF) antennas located within the vehicle, which it uses to communicate with up to eight different FOB with Integrated Key (FOBIK) units that have been programmed to the vehicle. The FOBIK units communicate with the PEM using Ultra High Frequency (UHF) communication on a frequency of 434 MegaHertz (MHz) using Frequency-Shift Keying (FSK) modulation, with a 10 kilobaud rate for the PE and KG functionality.

The number of antennas and the specific antenna locations are designed to ensure complete vehicle interior coverage. The LF antennas are each numbered and connected to the PEM on dedicated and sequentially numbered circuits. This arrangement allows the PEM to localize the positions of transmitting FOBIK units using a triangulation strategy. See the LC Low Frequency Antenna And Circuit Numbering table.

The location of a valid FOBIK is critical to the PE and KG features that the PEM will allow. The PEM has the ability to distinguish that a FOBIK is inside or outside of the vehicle. Inside of the vehicle is defined as anywhere within the passenger compartment and up to 10 centimeters (4 inches) from the exterior surfaces of the vehicle. Outside of the vehicle is defined as anywhere within about 10 centimeters (4 inches) and about 1.5 meters (5 feet) and not to exceed 2 meters (6.5 feet) from the exterior surfaces of each unlock switch, but is further differentiated by zones.

The PEM identifies the zone in which the valid FOBIK is located as the active zone, which determines which vehicle aperture becomes accessible. This vehicle has three outside zones: outside left, outside right and outside rear. The PEM will not respond to an input from a zone that is not active. For example: If the outside left zone is active, the PEM will respond to inputs from the left door smart handle, but not to inputs from the right door smart handle.

The PEM provides voltage and a clean ground to power the logic circuits and switches of each of the smart exterior door handles. If a door handle Lock , Unlock or Hall Effect switch is approached or activated, the door handle logic uses current modulation to communicate the changed switch state over the same two circuits for the PEM to sense. If a valid key has been verified, the PEM will then send the appropriate electronic Lock or Unlock message to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus.

When the PEM logic detects a PE input or KG request, the PEM and LF antennas challenge the FOBIK to identify whether it is a valid key. If a valid key is detected through the response from the FOBIK, the PEM sends the appropriate electronic message commands to other modules in the vehicle over the CAN data bus to enable an engine starting event, or to enable unlocking or locking of the appropriate vehicle aperture.

On vehicles so equipped, Remote Keyless Entry (RKE), Illuminated Entry, Remote Start, Vehicle Theft Alarm (VTA) and the Memory System each operate in the same manner with the PE and KG systems as without using either the factory default or preferred settings selected using the Customer Programmable Features function. If so desired, the PE system can also be disabled using the Customer Programmable Features function.

The PEM uses On-Board Diagnostics (OBD) and communicates with other modules in the vehicle as well as with a diagnostic scan tool using the Controller Area Network (CAN) data bus. This method of communication is used by the PEM to acquire vehicle configuration data, including customer programmable features. The PEM communicates with the Wireless Ignition Node (WIN) (also known as the Wireless Control Module/WCM or Sentry Key REmote Entry Module/SKREEM), the Powertrain Control Module (PCM) and the Totally Integrated Power Module (TIPM) (also known as the Forward Control Module/FCM) using the CAN data bus.

The PEM microprocessor monitors all of the PE and KG system circuits, then sets active and stored Diagnostic Trouble Codes (DTC) for any monitored system faults it detects. The PEM will also send electronic message requests to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) through the TIPM for the display of certain textual warning messages related to PE and KG system operation in the Electronic Vehicle Information Center (EVIC).

The hard wired inputs and outputs of the PEM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the PEM electronic controls or the communication between modules and other devices that provide some features of the PE and KG systems. The most reliable, efficient and accurate means to diagnose the PEM or the electronic controls and communication related to PE or KG system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

MODES OF OPERATION

As input signals to the Powertrain Control Module (PCM) change, the PCM adjusts its response to the output devices. For example, the PCM must calculate different injector pulse width and ignition timing for idle than it does for wide open throttle (WOT).

The PCM will operate in two different modes: Open Loop and Closed Loop .

During Open Loop modes, the PCM receives input signals and responds only according to preset PCM programming. Input from the oxygen (O2S) sensors is not monitored during Open Loop modes.

During Closed Loop modes, the PCM will monitor the oxygen (O2S) sensors input. This input indicates to the PCM whether or not the calculated injector pulse width results in the ideal air-fuel ratio. This ratio is 14.7 parts air-to-1 part fuel. By monitoring the exhaust oxygen content through the O2S sensor, the PCM can fine tune the injector pulse width. This is done to achieve optimum fuel economy combined with low emission engine performance.

The fuel injection system has the following modes of operation

1. Ignition switch ON
2. Engine start-up (crank)
3. Engine warm-up
4. Idle
5. Cruise
6. Acceleration
7. Deceleration
8. Wide open throttle (WOT)
9. Ignition switch OFF

The ignition switch On, engine start-up (crank), engine warm-up, acceleration, deceleration and wide open throttle modes are Open Loop modes. The idle and cruise modes, (with the engine at operating temperature) are Closed Loop modes.

OPERATION - PCM

1. Also refer to «MODES OF OPERATION»(ref-489300-S16596418332012072600000) .

The PCM operates the fuel system. The PCM is a pre-programmed, dual microprocessor digital computer. It regulates ignition timing, air-fuel ratio, emission control devices, charging system, certain transmission features, speed control, air conditioning compressor clutch engagement and idle speed. The PCM can adapt its programming to meet changing operating conditions.

The PCM receives input signals from various switches and sensors. Based on these inputs, the PCM regulates various engine and vehicle operations through different system components. These components are referred to as Powertrain Control Module (PCM) Outputs. The sensors and switches that provide inputs to the PCM are considered Powertrain Control Module (PCM) Inputs.

The PCM adjusts ignition timing based upon inputs it receives from sensors that react to: engine RPM, manifold absolute pressure, engine coolant temperature, throttle position, pedal value, transmission gear selection (automatic transmission), vehicle speed and the brake switch.

The PCM adjusts idle speed based on inputs it receives from sensors that react to: throttle position, vehicle speed, transmission gear selection, engine coolant temperature and from inputs it receives from the air conditioning clutch switch and brake switch.

Based on inputs that it receives, the PCM adjusts ignition coil dwell. The PCM also adjusts the generator charge rate through control of the generator field and provides speed control operation.

Note. PCM Inputs

1. A/C select AND request via CAN communication bus
2. Auto shutdown (ASD) sense
3. Brake switches 1 AND 2
4. Direct Battery voltage
5. EGR Position sensor
6. EVAP purge solenoid current sense
7. Camshaft position sensor signal
8. Crankshaft position sensor
9. CAN C bus communication for internal module communication and data link connection for scan tools
10. Engine coolant temperature sensor
11. 5 volts (primary)
12. 5 volts (secondary)
13. Fuel level via CAN communication bus from IPM
14. Generator (battery voltage sense) output
15. Ignition circuit sense (ACC AND Run/Start via hardwire from Integrated Power Module (IPM) while the Crank indication is via CAN communication bus)
16. Intake manifold air temperature sensor
17. Evaporative system ESIM vacuum switch (if equipped)
18. Manifold absolute pressure (MAP) sensor
19. Oil pressure
20. Oxygen sensors signals
21. Park/neutral switch
22. Power ground
23. Sensor return
24. Signal ground
25. Speed control switch states are determined by SCM and transmitted over the bus via CAN bus
26. SRV position sensor signal
27. Throttle position sensors and Pedal value sensors
28. Transmission pressure switch inputs (42RLE)
29. Transmission variable line pressure sensor (42RLE)
30. Transmission temperature sensor (42RLE)
31. Vehicle speed (ABS equipped) via CAN C bus from ABS module
32. Vehicle Speed (Non-ABS) from IPM via CAN C and Trans Turbine sensors (with pinion factor)

Note. PCM Outputs

1. A/C clutch relay
2. Auto shutdown (ASD) relay coil
3. CAN C bus messages for speedometer (non-ABS packages), voltmeter or generator lamp (if equipped), fuel gauge, oil pressure gauge/lamp, engine coolant temperature gauge and speed control indication warning lamp
4. CAN bus communication for inter module communication and data link connection for scan tools
5. EGR valve control solenoid (if equipped)
6. Electronic Throttle Control (ETC) motor
7. EVAP Purge solenoid
8. Fuel injectors
9. Fuel pump relay
10. Generator field driver
11. Ignition coils
12. Malfunction indicator lamp (also known as MIL). Driven through Bus Messages.
13. Oxygen sensor heater elements
14. Radiator cooling fan relay via CAN bus message to IPM
15. Short Runner Valve (SRV) actuator (if equipped)
16. Tachometer (if equipped). Driven through Bus Messages.
17. Transmission solenoids (42RLE only)
18. Transmission power relay

OPERATION - IGNITION CIRCUIT SENSE

When the ignition key is inserted, the position of the key is transmitted via the CAN bus to Integrated Power Module (IPM). When the key position is rotated to the ACC position or Run/Start position, the IPM energizes the Ignition ACC and/or Run/Start feed which will wake up the Powertrain Control Module (PCM) accordingly. These feeds are essentially fused switched battery voltage feeds fabricated by the IPM with relays or solid state devices. There is not Ignition Start feed to the PCM - this is handled by a CAN bus message from IPM to PCM. NOTE: Only on those applications with the 42RLE does the PCM receive an Ignition ACC feed.

The Steering Column Control Module (SCCM) includes an electronic circuit board, sometimes referred to as the Steering Control Module (SCM). The SCM is a Local Interface Network (LIN) bus master and a gateway for the Controller Area Network (CAN) data bus. Refer to COMMUNICATION, DESCRIPTION .

The microprocessor-based SCM provides power and ground to the multi-function switch of the SCCM, then utilizes integrated circuitry to monitor hard wired analog and digital return inputs from this switch. Except for the circuits for the optional heated steering wheel and the standard equipment Driver AirBag (DAB), which are pass-through circuits of the SCCM, the SCM also provides power and ground to all of the electronics carried on the steering wheel through a microprocessor contained in the right steering wheel switch, which is also a LIN slave.

The steering wheel-mounted electronics monitored by the SCM include the horn switch, the speed control switches, the remote radio switches, the hands-free communication switches and the Electronic Vehicle Information Center (EVIC) control switches, if the vehicle is so equipped. The LIN slave monitors the changing states of these switches through both hard wired analog and digital return inputs, then communicates those switch states to the SCM over the LIN bus. In response to those inputs, the internal circuitry of the SCM gateway then transmits electronic message outputs communicating all of the monitored switch state changes as well as SAS data to other electronic modules in the vehicle over the CAN bus.

A fixed connector receptacle of the SCCM connects the SCM to the vehicle electrical system through a single take out with connector from the instrument panel wire harness. The instrument panel wire harness take out has been intentionally provided with additional length to facilitate service removal and installation of the SCCM. However, following SCCM installation, this additional length must be pulled back and secured to the instrument panel structure to prevent the potential for undesirable rattling or buzzing noises while driving.

The SCM is connected to a fused B(+) circuit and receives a path to ground at all times. These connections allow it to remain functional regardless of the ignition switch position. Any input to the SCM that controls a vehicle system function that does not require that the ignition switch be in the ON position such as depressing the horn switch, prompts the SCM to wake up and transmit on the CAN data bus.

The service replacement SCCM is shipped with the clockspring pre-centered within the SCCM and with a plastic locking tab installed. This locking tab should not be removed until the SCCM has been properly installed on the steering column. If the locking tab is removed before the steering wheel is installed on a steering column, clockspring centering must be confirmed by viewing the inspection window on the clockspring rotor. If the black boxes of the clockspring tape are not visible in the inspection window, the entire SCCM must be replaced with a new unit. Refer to CLOCKSPRING, STANDARD PROCEDURE . Proper clockspring installation may also be confirmed by viewing the Steering Angle Sensor (SAS) data using a diagnostic scan tool.

The hard wired circuits between components related to the SCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the SCCM, the SCM or the electronic controls or communication between modules and other devices that provide some features of the SCCM. The most reliable, efficient, and accurate means to diagnose the SCCM, the SCM or the electronic controls and communication related to SCCM or SCM operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Following are brief descriptions of the systems that the WIN controls.