Power Steering Control Module (PSCM)
| ITEM | DESCRIPTION |
|---|---|
| 1 | Diaphragm |
| 2 | Power Steering Control Module (PSCM) system connector (connection for CAN communication) |
| 3 | Electric motor power supply connector |
| 4 | Torque sensor connector |
| 5 | Power steering control module cover |
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 signal from 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, fused power supply from the EJB. For 100% nominal power assistance, supply voltage must be between 10.5 V 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 systems 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:
- Vehicle speed and yaw rate, from the Anti-lock Brake System (ABS) control module. For additional information, Refer to: ANTI-LOCK CONTROL - STABILITY ASSIST - PROJECT 8
- Reverse gear signal from the BCM/GWM assembly (manual transmission only).
- Vehicle speed from the Transmission Control Module (TCM), through the BCM/GWM (automatic transmission only). For additional information, Refer to: TRANSMISSION DESCRIPTION
- Automatic steering requests, from the Parking Aid Control Module (PACM) (if park assist system is fitted). For additional information, Refer to: PARKING AID
- Auto stop/start system stop request from the PCM, through the BCM/GWM (if stop/start system is fitted). For additional information, refer to:
- 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
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 HS CAN chassis systems bus, of:
- Warning status, to the Instrument Cluster (IC) through the BCM/GWM assembly.
- Steering status to the PACM (if the vehicle is equipped with park assist system).
- Auto stop/start system engine stop inhibit and engine restart requests to the PCM through the BCM/GWM assembly via the HS CAN powertrain systems bus.