Sebring 2006

Powertrain Control Module

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Operation



The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent drivability and fuel economy. The Powertrain Control Module (PCM) is the control center of the vehicle. The PCM monitors numerous engine and vehicle functions. The PCM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The PCM also performs the diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the Malfunction Indicator Lamp (MIL). When the PCM detects a malfunction, the PCM stores a Diagnostic Trouble Code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. Review the components and wiring diagrams in order to determine which systems are controlled by the PCM. The following are some of the functions that the PCM controls:



The engine fueling
 
The Ignition Control (IC)
 
The Knock Sensor (KS) system
 
The Evaporative Emissions (EVAP) system
 
The Secondary Air Injection (AIR) system (if equipped)
 
The Exhaust Gas Recirculation (EGR) system
 
The automatic transaxle functions
 
The alternator
 
The Air Conditioning (A/C) clutch control
 
The cooling fan control
 

Removal & Installation



The Powertrain Control Module (PCM) engine control strategy prevents reduced idle speeds until after the engine operates for 200 miles (320 km). If the PCM is replaced after 200 miles (320 km) of usage, update the mileage and Vehicle Identification Number (VIN) in the new PCM. Use the scan tool to change the mileage and VIN in the PCM. If this step is not done, a Diagnostic Trouble Code (DTC) may be set and SKIM must be done or the car will not start if it is a SKIM equipped car. With a SKIM car, you must do a secret key transfer also. Refer to the appropriate Powertrain Diagnostic Manual and the scan tool.


WARNING
To avoid possible voltage spike damage to the PCM, the ignition key must be OFF, and the negative battery cable must be disconnected before unplugging the PCM connectors.


NOTE
Take note of any radio presets before disconnecting the negative battery cable.

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable and isolate the cable from making a connection unintentionally.
    WARNING
    If the negative battery cable is not disconnected properly, there is the possibility of damaging the PCM by contacting the positive battery cable at the Power Distribution Center (PDC).

  4.  
  5. Remove the 2 nuts holding the PCM and bracket.
  6.  
  7. Unlock and disconnect the electrical connectors at the PCM.
  8.  
  9. Remove the 3 fasteners holding the PCM to the bracket.

    Click image to see an enlarged view

    Fig. Expanded view of the Powertrain Control Module (PCM) location

  10.  

To install:

Use the scan tool to reprogram the new PCM with the original Vehicle Identification Number (VIN) and the vehicle-s actual mileage. If this step is not done, a Diagnostic Trouble Code (DTC) may be set.

  1. Install the PCM to the bracket.
  2.  
  3. Install the PCM and bracket to the vehicle and connect the electrical connectors and the lock connectors.
  4.  
  5. Install the 2 nuts and tighten.
  6.  
  7. Connect the negative battery cable and reprogram the radio and clock.
  8.  
  9. Using a scan tool, program the mileage and VIN into the PCM. Refer to the scan tool and the appropriate Powertrain Diagnostic Manual.
  10.  

Testing



The Powertrain Control Module (PCM) is programmed with test routines that test the operation of the various systems the PCM controls. Some tests monitor internal PCM functions. Many tests are run continuously. Other tests run only under specific conditions, referred to as conditions for running the DTC. When the vehicle is operating within the conditions for running a particular test, the PCM monitors certain parameters and determines if the values are within an expected range. The parameters and values considered outside the range of normal operation are listed as conditions for setting the DTC. When the conditions for setting the DTC occur, the PCM executes the action taken when the DTC Sets. Some DTC-s alert the driver via the Malfunction Indicator Lamp (MIL) or a message. Other DTC-s do not trigger a driver warning, but are stored in memory. The PCM also saves data and input parameters when most DTC-s are set. This data is stored in the freeze frame and/or failure records.

The DTC-s are categorized by type. The DTC type is determined by the MIL operation and the manner in which the fault data is stored when a particular DTC is set. In some cases, there may be exceptions to this structure. Therefore, when diagnosing the system, it is important to read the action taken when the DTC sets and the conditions for clearing the DTC.

Many intermittent open or shorted circuits come and go with harness and connector movement caused by vibration, engine torque, bumps, and rough pavement.

  1. Test the wiring harness and connectors by performing the following:

    Move the related PCM connectors and wiring while monitoring the appropriate scan tool data
     
    With the engine running, move the related connectors and wiring while monitoring engine operation
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary
     

  2.  
  3. Test the electrical connections and/or wiring by performing the following:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body, backed-out
     
    Inspect for improperly formed or damaged terminals. Test for incorrect terminal tension
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and stiff sections of wire in the suspect circuits
     
    Inspect for wires that are broken inside the insulation
     

  4.  
  5. Repair or replace as necessary.
  6.  

Standard Procedure-PCM/Skim Programming

NOTE
Before replacing the Powertrain Control Module (PCM) for a failed driver, control circuit, or ground circuit, be sure to check the related component/circuit integrity for failures not detected due to a double fault in the circuit. Most PCM driver/control circuit failures are caused by internal component failures (i.e. relay and solenoids) and shorted circuits (i.e. pull-ups, drivers, and switched circuits). These failures are difficult to detect when a double fault has occurred and only one DTC has set.

  1. When a PCM and the SKIM are replaced at the same time; perform the following steps in order:
    1. Program the new PCM.
    2.  
    3. Program the new SKIM.
    4.  
    5. Replace all ignition keys and program them to the new SKIM.
    6.  

  2.  

Programming Ignition Keys To The Skim
  1. Turn the ignition switch ON with the transmission in park/neutral.
  2.  
  3. Use the scan tool and select THEFT ALARM, SKIM, then MISCELLANEOUS.
  4.  
  5. Select PROGRAM IGNITION KEYS.
  6.  
  7. Enter the secured access mode by entering the vehicle four-digit PIN.
    NOTE
    A maximum of eight keys can be learned to each SKIM. Once a key is learned to a SKIM, it (the key) cannot be transferred to another vehicle.

  8.  
  9. If the ignition key programming is unsuccessful, the scan tool will display one of the following messages:
    1. Programming Not Attempted-The scan tool attempts to read the programmed key status and there are no keys programmed into SKIM memory.
    2.  
    3. Programming Key Failed (Possible Used Key From Wrong Vehicle)-SKIM is unable to program key due to one of the following:

      A faulty ignition key transponder
       
      An ignition key is programmed to another vehicle
       
      8 Keys Already Learned, Programming Not Done-SKIM transponder ID memory is full.
       

    4.  

  10.  
  11. To begin again with the ignition key programming, obtain ignition keys to be programmed (8 keys maximum).
  12.  
  13. Using the scan tool, erase all ignition keys by selecting MISCELLANEOUS and ERASE ALL CURRENT IGN. KEYS.
  14.  
  15. Program all ignition keys.
  16.  
  17. Learned Key In Ignition-Ignition key transponder ID is currently programmed in SKIM memory.
  18.  

Programming The PCM

The SKIS Secret Key is an ID code that is unique to each SKIM. This code is programmed and stored in the SKIM, PCM, and transponder chip (ignition keys). When replacing the PCM, it is necessary to program the secret key into the new PCM using a scan tool. Perform the following steps to program the secret key into the PCM.

  1. Turn the ignition switch ON with the transmission in park/neutral.
  2.  
  3. Use the scan tool and select THEFT ALARM, SKIM, then MISCELLANEOUS.
  4.  
  5. Select PCM REPLACED (GAS ENGINE).
  6.  
  7. Enter the secured access mode by entering the vehicle four-digit PIN.
  8.  
  9. Select ENTER to update the PCM VIN.
    NOTE
    If three attempts are made to enter the secure access mode using an incorrect PIN, the secured access mode will be locked out for one hour. To exit this lockout mode, turn the ignition to the RUN position for one hour, then enter the correct PIN. (Ensure all the accessories are turned OFF. Also, monitor the battery state and connect a battery charger if necessary).

  10.  
  11. Press ENTER to transfer the secret key (the SKIM will send the secret key to the PCM).
  12.  
  13. Press Page Back to get to the Select System menu and select ENGINE, MISCELLANEOUS, and SRI MEMORY CHECK.
  14.  
  15. The scan tool will ask, -Is odometer reading between XX and XX-- Select the YES or NO button on the scan tool. If NO is selected, the scan tool will read, -Enter odometer Reading-From I.P. odometer.- Enter the odometer reading from the Instrument Panel (IP) and press ENTER.
  16.  

Programming The Skim
  1. Turn the ignition switch ON with the transmission in park/neutral.
  2.  
  3. Use the scan tool and select THEFT ALARM, SKIM, then MISCELLANEOUS.
  4.  
  5. Select PCM REPLACED (GAS ENGINE).
  6.  
  7. Program the vehicle four-digit PIN into SKIM.
  8.  
  9. Select COUNTRY CODE and enter the correct country.
    NOTE
    Be sure to enter the correct country code. If the incorrect country code is programmed into SKIM, the SKIM must be replaced.

  10.  
  11. Select YES to update the VIN (the SKIM will learn the VIN from the PCM).
  12.  
  13. Press ENTER to transfer the secret key (the PCM will send the secret key to the SKIM).
  14.  
  15. Program the ignition keys to SKIM.
    NOTE
    If the PCM and the SKIM are replaced at the same time, all vehicle keys will need to be replaced and programmed to the new SKIM.

  16.  

 
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