GM Service Manual Online
For 1990-2009 cars only

The PG starter motors are non-repairable starter motors. They have pole pieces that are arranged around the armature. Both solenoid windings are energized. The pull-in winding circuit is completed to the ground through the starter motor. The windings work together magnetically to pull and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the engine. Moving at the same time, the plunger also closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding because battery voltage is applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine starts, pinion overrun protects the armature from excessive speed until the switch is opened.

When the ignition switch is released from the START position, the CRANK Relay opens and battery voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to the ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now opposite the direction of the current flow when the winding was first energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, causes the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter circuit is turned off.

Circuit Description (Key Start)

When the ignition switch is placed in the Start position a discrete 12 volts signal is supplied to the body control module (BCM) notifying it that the ignition is in the Start position. The BCM then supplies a class 2 message to the engine control module (ECM) / powertrain control module (PCM) notifying it that CRANK has been requested. At the same time the BCM is supplying 12  volts for the IGN 1 Relay closing it and supplying battery positive voltage for the crank relay coil. The ECM/PCM verifies that the transmission is in Park or Neutral. If it is, the ECM/PCM grounds the control circuit of the CRANK Relay. When this occurs battery positive voltage is supplied through the switch side of the crank relay to the S terminal of the starter solenoid.

Remote Vehicle Start (RVS)

To operate the function, first press and release the lock button on the key fob, then press the remote vehicle start (RVS) button for 2 seconds. The vehicle park lamps will be illuminated to indicate that the engine is running. The vehicle doors will be able to be unlocked. The seat belt reminder chime will be on when in an RVS event. The RVS function is allowed to start the vehicle 2 times for 10-minute intervals. If the body control module (BCM) receives a second request for an RVS event while already operating in RVS, then the first timer times out and then the second timer starts. If the RVS button was pressed for the first time and then 7 minutes later the RVS button was pressed a second time, the total time for the RVS event would be 17 minutes. When the RVS button is pressed for the second time, the first 10-minute interval automatically stops and the BCM starts counting the second 10-minute interval. After the first event times out, 10 minutes, the second event must be requested within 20 minutes or the function is disabled.

RVS can be deactivated by pressing the RVS button on the key fob, pressing the hazard switch, or inserting the ignition key and cycling it to the ON position and then OFF again. There are also other safety and security measures that will deactivate RVS, these include depressing the accelerator pedal or opening the hood. RVS will not function with any current or history codes set. The park lights will flash once when the RVS signal is received by the BCM, but the vehicle will not start.

RVS is designed to transition for RVS to normal key ON, engine run operation without any apparent change to the customer except inserting the ignition key and turning it to the RUN position.

While in RVS mode all modules that are powered by the Run/Crank shall be active and understand that RVS is active. All on-board diagnostics (OBD) II functions shall also be active.

The current state of RVS can be viewed through the driver information center (DIC) display under the Remote Start. The display will read either On or Off.

The HVAC preset RVS settings are as follows:

    • Inside air temperature input below 22°C (72°F) the HVAC system will set the blower motor speed to high speed, set the mode door to the defrost position, set the temperature door to the full hot position, and set the recirculation door to the outside air position.
    • Inside air temperature input above 26°C (79°F) the HVAC system will set the blower motor speed to high speed, set the mode door to the panel position, set the temperature door to the full cold position, request air conditioning (A/C) compressor operation, and set the recirculation door to the recirculate position.
    • Inside air temperature input between 22-26°C (72-79°F) the HVAC system will set the blower motor speed to a medium speed, set the mode door to the panel position, set the temperature door to the full cold position, request A/C compressor operation, and set the recirculation door to the outside air position.

Once the ignition switch is placed to the RUN position the HVAC system reverts back to its last known setting.

Disable RVS

To disable the remote vehicle start (RVS) function perform the following steps:

  1. All doors must be closed.
  2. Turn ON the ignition, with the engine OFF.
  3. Press the Options button on the driver information center (DIC) until Personal Programming is displayed.
  4. Press the Set/Reset button.
  5. Press the Options button until REMOTE START is displayed.
  6. Press the Set/Reset button until OFF is displayed.

Enable RVS

To enable the remote vehicle start (RVS) function perform the following steps:

  1. Turn ON the ignition, with the engine OFF.
  2. Press the Options button on the driver information center (DIC) until Personal Programming is displayed.
  3. Press the Set/Reset button.
  4. Press the Options button until REMOTE START is displayed.
  5. Press the Set/Reset button until ON is displayed.

Hood Ajar Switch

The hood switch provides status of the hood to the body control module (BCM) for remote vehicle start (RVS) functions. It is integrated into the hood latch assembly. The hood ajar switch provides an input to the BCM. When the hood is closed, the hood ajar open signal circuit is approximately battery voltage. The hood ajar closed signal circuit is pulled low to ground. The opposite occurs when the hood is opened.

Circuit Description (RVS)

The body control module (BCM) is the main controller for remote vehicle start (RVS). It handles the majority of the RVS functions from how long RVS last to protecting the vehicle from theft while RVS is active.

Once the BCM receives a signal from the key fob, it reviews the following information to determine if a Crank Request message will be sent to the ECM/PCM to activate RVS:

    • Valid hood ajar switch closed signal.
    • The key is not in the ignition.
    • The doors are locked.
    • The hazard switch is OFF.

The ECM/PCM relies on the RVS message from the BCM to enable RVS when the Crank Request signal is received. If the ECM/PCM does not receive a valid RVS message from the BCM it will not ground the control circuit of the CRANK Relay and start the engine. While the ECM/PCM is in RVS mode it will cut fuel to the engine if any of the following additional conditions occur:

    • Vehicle speed is greater than 0 km/h.
    • Engine overheating.
    • Low oil pressure.
    • The malfunction indicator lamp (MIL) is commanded ON.
    • Engine crank time is greater than 30 seconds.
    • Engine speed greater than 2,000 RPM for more than 10 seconds.
    • Engine speed greater than 4,000 RPM for more than 2 seconds.
    • The throttle position (TP) is greater than 10 percent for 2 seconds.
    • The remote start timer equals 0.