Electronic Control Modules - Service Information: Overview Dodge Avenger II facelift

DESCRIPTION

The primary on-board communication network between microprocessor-based electronic control modules 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 nodes in the vehicle. 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 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/Central GateWay (TIPM or TIPMCGW) 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 is connected 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/Central GateWay (TIPM or TIPMCGW) 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 message is carried 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 ElectroMechanical Instrument Cluster (EMIC) (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 Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM). Both the EMIC and the SKREEM 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 TIPM and the Powertrain Control Module (PCM).

The termination resistance of two dominant nodes is 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 Central GateWay (TIPMCGW).

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 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 is awake 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 will keep 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 will provide 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 will also identify certain failures for both CAN-B bus signal wires.

Scheme 1

The Data Link Connector (DLC) (1) is a 16-way molded plastic connector that is part of the instrument panel wire harness. This connector is located at the lower edge of the instrument panel, outboard of the steering column. The connector insulator is retained by integral snap features within a rectangular cutout in a mounting bracket integral to the lower instrument panel and inboard of the inside hood release on the inner cowl side trim.

The Data Link Connector (DLC) is an industry-standard 16-way connector that permits the connection of a diagnostic scan tool to the Controller Area Network (CAN) data bus for interfacing with, configuring, and retrieving Diagnostic Trouble Code (DTC) data from the electronic modules that reside on the data bus network of the vehicle.

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 or when in a traction control or Electronic Stability Control (ESC) situation. The ABM utilizes a 47-way electrical 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 (1) is mounted to the HCU (2) as part of the Integrated Control Unit (ICU). The ICU is located in the engine compartment on the inboard side of the right body frame rail behind the strut tower. For information on the ICU, refer to INTEGRATED CONTROL UNIT (ICU), DESCRIPTION .

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 ABS indicator in the instrument cluster.
8. Illuminate the yellow ESC/BAS indicator in the instrument cluster (if equipped).

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 ABS and yellow ESC/BAS indicators 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 front door control modules (also known as a Driver Door Module/DDM, a Passenger Door Module/PDM or Front Door Multiplex/MUX Modules) contain logic circuits that monitor various hard wired analog and low current, multiplexed inputs from the door ajar, power window, power lock and power mirror switches on their respective doors. They also receive Controller Area Network (CAN) B 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 front door control modules also monitor hard wired power window motor Hall effect sensor inputs.

The program logic within the front door control module allows the microprocessor to prioritize all of these inputs and determine the tasks it needs to perform. These tasks are then completed either by controlling hard wired outputs to the various motors, actuators or lamps on its own or the rear doors, or by sending electronic message requests over the CAN-B bus to the appropriate electronic module in the vehicle.

The front 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. 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.

The hard wired inputs and outputs of the front 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, power lock or interior lighting system features the front door control modules provide. The most reliable, efficient and accurate means to diagnose the front 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-485483-S36036329462012071300000) .
3. Beginning with the black 10-way electrical connector (1), then the brown 20-way electrical connector (2) followed by, if the vehicle is so equipped, the black 12-way electrical connector (3) from the connector receptacles of the door control module.
4. Remove the four screws that secure the door control module to the front door hardware module carrier.
5. Remove the door control module from the door hardware module carrier.

The AWD ECM (electronic control module) mounts on the driver side cowl side panel, where it is concealed by the instrument panel. It communicates with other systems over the high-speed CAN-C bus.

Scheme 4

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 all-wheel-drive system requires no driver input or control. Under most driving conditions, it is passive and power is transmitted to the front wheels alone. The system functions to optimize traction and handling under the following conditions

Anticipates slip by responding to pedal position unlike all-wheel drive systems that rely on pumps or viscous fluids to transfer torque, the system requires no front-to-rear slippage for activation. This allows the system to transfer torque in response to accelerator pedal position. If the driver is asking for a lot of power, the system immediately starts clamping the Electronically Controlled Coupling (ECC), transferring a high percentage of power to the rear wheels. This avoids front wheel slippage, as power to propel the car is transmitted through all four tires. This mode of operation is called open-loop operation in that there is no feedback to affect the torque transfer.

Modulates torque to optimize traction on slippery surfaces a second, closed loop, operating mode uses feedback from the wheel-speed sensors to determine the appropriate torque transfer. When the front wheels slip, the all-wheel-drive electronic control module tells the ECC to start clamping, sending power to the rear wheels. Attempting the same aggressive launch described above with the front wheels on ice and the rear wheels on dry pavement, the ECC sends even more torque to the rear wheels to minimize slippage and launch the vehicle. Both modes are always active and the maximum of the two is chosen. Power to the rear wheels is modulated during lost of traction while traveling at freeway speeds; for example, hydroplaning on a puddle of water, will send very little power to the rear wheels because the controller knows at those speeds a lot of power is not needed at the rear wheels.

Prevents binding during low-speed turns a third condition, which is independent of the others, uses the ESC steering angle sensor to determine when the vehicle is turning in a tight circle. This condition causes the electronic control module to reduce torque to the rear wheels to prevent binding in the driveline. The electronic control module is always checking for this condition as well.

Influences handling at moderate speeds. The AWD system is used to influence vehicle dynamics. Other manufacturers limit AWD to aiding traction or providing off-road capability. They concentrate on launching the vehicle or going off road at speeds up to about 25 mph (40 km/hr). Above that speed range, they use it to limit wheel slip for traction. Additional ECM calibration controls torque to the rear wheels for improved handling in the 25-65 mph (40-105 km/hr) range. In this speed range, the system utilizes torque to the rear wheels during cornering with the throttle open to make the car turn more easily - make the handling more neutral. This is more readily accomplished with an electronically controlled system than with viscous-coupling or gerotor systems that require some degree of front-to-rear slip to transfer torque to the rear wheels. Above 53 mph (113 km/hr), the control strategy provides minimal torque to the rear wheels under normal driving conditions to aid fuel economy.

Works with ESC and Traction Control the electronic control module also interfaces with the ESC and traction control systems. The interface allows the ESC system to use the ECC to help gain control of the vehicle. For this purpose, torque transmitted to the rear wheels by the ECC can be reduced. The AWD system is not traction control. It only works on situations where front-to-rear traction varies, for instance, front wheels on ice, rear wheels on dry pavement or climbing steep grades. AWD does not aid side-to-side traction. ESC does that through brake intervention.

The heated seat module operates on fused battery current received from the ignition switch. The module is grounded to the body at all times through the electrical connector. Inputs to the module include Local Interface Network (LIN) data bus messages and standard hardwired 12 volt power and ground. In response to the LIN inputs the heated seat module will control the battery current to the appropriate heated seat elements.

When a heated seat switch LIN data bus signal is received by the heated seat module, the module energizes the selected heated seat element. The Low heat set point is about 38° C (100.4° F), and the High heat set point is about 42° C (107.6° F).

In addition to operating the heated seat elements, the heated seat module sends LED illumination messages to the instrument cluster, sometimes referred to as the Cab Compartment Node (CCN) via the LIN data bus. The CCN then sends the LED illumination message to the accessory switch bank so that the appropriate LEDs are illuminated for any given heating level. Pressing the switch once will select high-level heating. Pressing the switch a second time will select low-level heating. Pressing the switch a third time will shut the heating elements off.

If the heated seat module detects a heated seat element OPEN or SHORT circuit, it will record and store the appropriate Diagnostic Trouble Code (DTC).

Use the scan tool to reprogram the new pcm with the vehicle's original identification number (vin) and the vehicle's original mileage. If this step is not done a Diagnostic Trouble Code (DTC) may be set.

The PCM supplies two regulated 5 volts supplies - a 5V primary and a 5V secondary (auxiliary) to the following sensors

1. Camshaft Position Sensor (5V secondary)
2. Crankshaft Position Sensor (5V primary)
3. EGR Position feedback sensor (5V secondary) (if equipped)
4. Engine coolant temperature sensor (connected to 5V internal via a pullup resistor)
5. Inlet Air Temperature Sensor (connected to 5V internal via a pullup resistor)
6. Knock sensor (connected to 5V internal via a pullup resistor)
7. Manifold absolute pressure sensor (5V secondary)
8. Oil Pressure Switch (connected to 5V internal via pullup resistor)
9. Pedal Value Sensor #1 (5V Primary)
10. Pedal Value Sensor #2 (5V Secondary)
11. SRV Position Feedback Sensor (5V Secondary)
12. Throttle Position Sensors (5V Primary)
13. Variable Line Pressure Sensor (5V Secondary)

The microprocessor-based Steering Control Module (SCM) utilizes integrated circuitry to monitor hard wired analog and multiplexed inputs from both the right and left multi-function switches. In response to those inputs, the internal circuitry of the SCM allow it to transmit electronic message outputs to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) over the Local Interface Network (LIN) data bus.

In response to the SCM inputs the internal circuitry and programming of the EMIC, which is also the LIN master module in the vehicle, allow it to control and integrate many electronic functions and features of the vehicle through both hard wired outputs and the transmission of electronic message outputs to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. Refer to COMMUNICATION, DESCRIPTION .

The SCM is connected to both a fused B(+) circuit and a fused ignition switch output (run-start) circuit. It 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 turning on the lights, prompts the SCM to wake up and transmit on the LIN data bus.

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 SCM or the electronic controls or communication between modules and other devices that provide some features of the SCM. The most reliable, efficient, and accurate means to diagnose the SCM or the electronic controls and communication related to SCM operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

All of the electrical current distributed throughout this vehicle is directed through the standard equipment Totally Integrated Power Module (TIPM). The molded plastic TIPM housing is located on the right side of the engine compartment. The TIPM housing has a molded plastic cover. The TIPM cover is easily removed for service access and has a convenient fuse layout label affixed to the inside surface of the cover to ensure proper component identification.

The TIPM housing is secured to the TIPM mounting bracket by four clips integral to the TIPM housing. All of the TIPM outputs are through the integral engine compartment wire harness.

All of the current to the Totally Integrated Power Module (TIPM) comes directly from the positive battery cable to a stud located on the bottom of the TIPM. The cable is secured to the TIPM stud with a nut. Internal connection of all the TIPM circuits is accomplished by an intricate network of hard wiring and bus bars. Refer to the appropriate wiring information for complete circuit diagrams.

The fuses, relays and TIPM housing assembly are available for service replacement.

Scheme 5

Scheme 6

1. Disconnect and isolate the negative battery cable.
2. Release the Totally Integrated Power Module (TIPM) cover retaining clips and open the TIPM cover (1).
3. Depress the mounting clips (2) to disengage and remove the TIPM housing (3) from its mounting bracket.
4. Access the bottom of the TIPM.
5. Remove the TIPM B+ cable retainer (1).
6. Remove the B+ cable (2) from the TIPM stud (3).
7. Disconnect the harness connectors from the bottom of the TIPM.
8. Remove the TIPM from the vehicle.