Power Steering Control Module (PSCM): Notes

The Power Steering Control Module (PSCM) is located on the end of the electric motor, under a sealed cover. A diaphragm in the cover, made from a waterproof breathable fabric, maintains the interior of the cover at ambient pressure, avoiding the need for an open vent.

As well as the control circuitry, the PSCM also contains the power electronics for operating the electric motor.

Power assistance is provided when the following are present:

• A permanent power supply from the Engine Junction Box (EJB).
• An ignition from the ignition the Body Control Module/Gateway Module (BCM/GWM) assembly.
• The power mode Controller Area Network (CAN) bus signal is set to engine running.

Electrical power for operation of the electric motor is provided by a permanent supply from the EJB. For 100% nominal power assistance, supply voltage must be between 10.5 and 18 V. If supply voltage is outside of these limits, power assistance is either reduced or discontinued.

The PSCM receives hardwired digital inputs from the torque sensor and messages on the High Speed (HS) Controller Area Network (CAN) chassis system bus from the following:

• Power mode from the BCM/GWM assembly.
• Engine speed from the Powertrain Control Module (PCM) via the BCM/GWM assembly. For additional information:

  Refer to ELECTRONIC ENGINE CONTROLS - INGENIUM I4 2.0L DIESEL .

  Refer to ELECTRONIC ENGINE CONTROLS - INGENIUM I4 2.0L PETROL .

  Refer to ELECTRONIC ENGINE CONTROLS - V6 S/C 3.0L PETROL .

• Vehicle speed and yaw rate, from the Anti-lock Brake System (ABS) control module.

  For additional information, refer to: ANTI-LOCK CONTROL - STABILITY ASSIST (Description and Operation).

• Automatic steering requests, from the Parking Aid Control Module (PACM) (if equipped).

  For additional information, refer to: PARKING AID (Description and Operation).

• Reverse gear signal from the BCM/GWM assembly (manual transmission only).
• Vehicle speed from the Transmission Control Module (TCM), through the BCM/GWM assembly (automatic transmission only).

  For additional information, refer to: TRANSMISSION DESCRIPTION (AWD/RWD, Description and Operation).

• Power mode from the BCM/GWM assembly.
• Auto stop/start system stop request from the PCM, through the BCM/GWM assembly (Auto stop/start if equipped). For additional information:

  Refer to STARTING SYSTEM (2.0L Diesel, Description and Operation).

  Refer to STARTING SYSTEM (2.0L Petrol, Description and Operation).

  Refer to STARTING SYSTEM (V6 S/C 3.0L Petrol, Description and Operation).

• Lane Departure Warning (LDW) haptic steering wheel vibration request from the Image Processing Module (IPMA/B) (if equipped).

  For additional information, refer to: WARNING DEVICES (Description and Operation).

The Power Steering Control Module (PSCM) uses the input data and software algorithms to control electric motor operation.

If required, the PSCM can also transmit outputs on the following HS CAN chassis system buses:

• Warning status, to the Instrument Cluster (IC) through the BCM/GWM assembly.
• Steering status, to the PACM (if equipped).
• Auto stop/start system engine stop inhibit and engine restart requests to the Powertrain Control Module (PCM) through the BCM/GWM assembly via the High Speed (HS) Controller Area Network (CAN) powertrain system bus.