C0450
DTC C0450
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC C0450 01
- Steering Assist Control Actuator Circuit Short to Battery
DTC C0450 02
- Steering Assist Control Actuator Circuit Short to Ground
DTC C0450 04
- Steering Assist Control Actuator Circuit Open
Diagnostic Fault Information
Circuit/System Description
The actuator is a variable electromagnetic actuator, which consists of one multiple-pole ring-style permanent magnet, with a pole piece, and an electromagnetic coil assembly. By commanding currents between -3 to +3 A through the coils the steering effort will be adapted accordingly.
Conditions for Running the DTC
* System voltage between 9-16 V
* Engine running
Conditions for Setting the DTC
The variable effort steering detects a short to battery, short to ground or an open circuit in the actuator circuits.
C0450 01
If the coil feedback voltage is measured greater than 8 V during the initialization of the module, the DTC will be set.
C0450 02
If the coil feedback voltage is measured less than 3.4 V during the initialization of the module, the DTC will be set.
C0450 04
If the coil current is measured to be less/greater than 1.0 A from the commanded current, the DTC will be set.
Action Taken When the DTC Sets
* DTC C0450 is stored in memory.
* The fault lamp illuminates or the driver information center displays the service power steering message.
* The variable effort steering module goes in to shutdown mode.
Conditions for Clearing the DTC
* The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.
* The variable effort steering automatically clears the history DTC when a current DTC is not detected in 40 consecutive communication wake-up enable cycles.
Diagnostic Aids
The vehicle may need to be driven to view full variable power steering solenoid commanded and actuator feedback data parameters.
Reference Information
Schematic Reference
Power Steering Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Power Steering System Description and Operation Power Steering System Description and Operation (NXC)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
Note: It is recommended that Component Testing is performed before Circuit/System Testing when diagnosing the variable power steering solenoid.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connectors at the M72 Variable Power Steering Solenoid Valve. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 ohms between each control terminal listed below and ground.
* M72 Variable Power Steering Solenoid Valve connector terminal 1
* M72 Variable Power Steering Solenoid Valve connector terminal 2
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance at the appropriate circuit.
• If less than 2 ohms, replace the K43 Power Steering Control Module.
• If less than 10 ohms
3. Ignition OFF, disconnect the harness connector at the K43 Power Steering Control Module, Ignition ON.
4. Test for less than 1 V between each control terminals listed below and ground.
* K43 Power Steering Control Module connector X1 terminal 2
* K43 Power Steering Control Module connector X1 terminal 3
• If 1 V or greater
Repair the short to voltage at the appropriate circuit.
• If less than 1 V
5. Replace the K43 Power Steering Control Module.
Component Testing
1. Ignition OFF, disconnect the harness connector at the M72 Variable Power Steering Solenoid Valve.
2. Test for 1.6-3.1 ohms between terminal 1 and 2.
• If less than 1.6 ohms or greater than 3.1 ohms
Replace the M72 Variable Power Steering Solenoid Valve.
• If between 1.6-3.1 ohms
3. Test for infinite resistance between each terminal and the M72 Variable Power Steering Solenoid Valve housing case.
• If less than infinitive resistance
Replace the M72 Variable Power Steering Solenoid Valve.
• If infinitive resistance
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Steering Gear Replacement (FWD) Steering Gear ReplacementSteering Gear Replacement (AWD) Steering Gear Replacement
* Control Module References Control Module References for power steering control module replacement, programming and setup.