DTC C0450 — NV7
Diagnostic Instructions
DTC Descriptors
DTC C0450 00: Steering Assist Control
Solenoid Valve Circuit Malfunction
DTC C0450 04: Steering Assist Control
Solenoid Valve Circuit Open
DTC C0450 08: Steering Assist Control
Solenoid Valve Circuit Performance - Signal Invalid
DTC C0450 0B: Steering Assist Control
Solenoid Valve Circuit High Current
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Variable Effort Steering High Control
|
C0450 00
|
C0450 04
|
C0450 00
|
C0450 08
|
Variable Effort Steering Low Control
|
C0450 00
|
C0450 04
|
C0450 00
|
C0450 08
|
Circuit/System Description
The electronic brake control module (EBCM) controls the current
through the variable effort steering actuator located on the
steering gear. The current used to control the actuator is between
0-1 A. At low speeds and during car park manoeuvres the
current is applied to the actuator causing the orifice to open
increasing fluid flow and reducing the steering effort. At high
speeds the orifice is commanded closed by reducing current through
the actuator and restricting fluid flow increasing steering effort.
The EBCM monitors and compares the commanded and feedback current
parameters to detect malfunctions in the variable effort steering
system.
Conditions for Running the DTC
• |
Ignition voltage is greater than
8 volts. |
Conditions for Setting the DTC
A malfunction, open/high resistance, an invalid signal or a high
current is detected on the high control or low control circuit.
Action Taken When the DTC Sets
• |
The driver information centre displays SERVICE
POWER STEERING SYSTEM. |
• |
The variable effort steering system is disabled
for the remainder of the ignition cycle. |
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 EBCM automatically clears the history DTC when
a current DTC is not detected in 100 consecutive drive
cycles. |
Diagnostic Aids
The vehicle may need to be driven to view full actuator
commanded and actuator feedback data parameters.
Reference Information
Schematic Reference
Power Steering Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Variable Effort Steering System Description and Operation
Electrical Information Reference
Scan Tool Reference
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 actuator because the module will default and does
not supply voltage to the sensor when the DTC is set.
- Ignition OFF, disconnect the harness connector at the
M72 Variable Power Steering Solenoid Valve.
- Ignition ON, verify that a test lamp illuminates
between the control circuit terminal A and ground.
⇒ |
If the test lamp does not illuminate, test the
control circuit for a short to ground or an open/high
resistance. |
- Ignition OFF, connect the test lamp between the
control circuit terminal A and the control circuit terminal B.
- Ignition ON, verify the test lamp briefly illuminates
for approximately 1 s, then turns OFF.
⇒ |
If the test lamp is always ON, test the control
circuit terminal B for a short to ground. If the circuit tests
normal, replace the K17 Electronic Brake Control Module. |
⇒ |
If the test lamp is always OFF, test the control
circuit terminal B for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the
K17 Electronic Brake Control Module. |
- If all circuits test normal, test or replace the
M72 Variable Power Steering Solenoid Valve.
Component Testing
Static Test
- Ignition OFF, disconnect the harness connector at the
M72 Variable Power Steering Solenoid Valve.
- Test for 2.5-10 Ω between the control terminals A
and B.
⇒ |
If not within the specified range, replace the
M72 Variable Power Steering Solenoid Valve. |
- Test for infinite resistance between each terminal and
the M72 Variable Power Steering Solenoid Valve
housing/case.
⇒ |
If not the specified value, replace the
M72 Variable Power Steering Solenoid Valve. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|