• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
EPS B+ | U2143 00, U211 00,* | U2143 00, U211 00,* | -- | -- |
EPS Ignition | U2143 00, U211 00,* | U2143 00, U211 00,* | -- | -- |
5-V Reference | C0545 00 | C0545 00 | -- | -- |
Steering Position Sensor Signal | C0460 00 | C0460 00 | C0460 00 | C0460 00 |
Steering Position Sensor Signal | C0460 00 | C0460 00 | C0460 00 | C0460 00 |
Torque Sensor Signal | C0545 00 | C0545 00 | C0545 00 | C0545 00 |
Torque Sensor Signal | C0545 00 | C0545 00 | C0545 00 | C0545 00 |
Low Reference | C0545 00 | C0545 00 | -- | -- |
PSCM Ground | -- | U2143 00, U211 00,* | -- | -- |
* No communication with PSCM |
The power steering control module (PSCM) continuously monitors the position of the power steering motor, the voltage and current levels commanded to it. It uses the motor position data to determine if a loss of mechanical coupling has occurred between the motor and the steering column shaft. The PSCM also compares the commanded and feedback current levels to detect malfunctions in the power steering motor.
• | Engine running. |
• | Power steering system voltage is 9-16 volts. |
• | Steering input is present. |
A short to ground, short to voltage, or an open in the power steering motor, or the circuits to the motor.
The PSCM detects a motor position value that exceeds the mechanical travel limitation of the system, or more than 4.5 steering wheel revolutions.
• | The DTC is stored in memory. |
• | The driver information center (DIC) displays the POWER STEERING warring message. |
• | No steering assist is provided. |
• | A current DTC will clear on the next malfunction-free ignition cycle. |
• | A history DTC will clear after 100 consecutive malfunction-free ignition cycles. |
If the intermediate shaft, or the steering gear coupler is disconnected during a previous repair, and the steering wheel is turned more than 4.5 revolutions with the engine ON, DTC C0475 64 will set.
Power Steering System Description and Operation
Control Module References for scan tool information
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the PSCM. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | If separation or damage is present, replace the power steering motor assembly. If the motor assembly is OK, replace the steering column assembly. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for PSCM replacement, setup, and programming |