Power Steering System Chevrolet Equinox I

Fastener Tightening Specifications

Fastener Tightening Specifications

Scheme 1

Scheme 2

Scheme 3

Power Steering Control Module (PSCM) C1 Connector Part Information OEM: 7123-4123-30 Service: 88953301 2-Way F (BK) Pin Wire Color Circuit No. Function + RD/BK 42 Battery Positive Voltage - BK 350 Ground

Power Steering Control Module (PSCM) C2 Connector Part Information OEM: 776195-6 Service: See Catalog 6-Way F (GY) Pin Wire Color Circuit No. Function 1-3 - - Not Used 4 PU 1807 Class 2 Serial Data 5 - - Not Used 6 PK 739 Ignition 1 Voltage

Power Steering Control Module (PSCM) C3 Connector Part Information OEM: 7123-4123-30 Service: 88953301 2-Way F (BU) Pin Wire Color Circuit No. Function + RD - Left Assist Motor Control - BK - Right Assist Motor Control

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

System Familiarization

Review the electric power steering (EPS) system operation in order to familiarize yourself with the correct system functions and operations. Refer to Power Steering System Description and Operation .

Visual/Physical Inspection

1. Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/equinox/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor) in Wiring Systems.
2. Inspect for aftermarket components such as tires, or wheels which could affect the operation and/or performance of the power steering system.
3. Inspect the steering column for accident damage. Refer to «Steering Column Accident Damage Inspection»(/chevrolet/equinox/i-2004-2009/remont/ignition-switchsteering-lock/#steering-wheel-steering-column) in Steering Wheel and Column.

System Diagnosis

After incorrect system operation has been verified and that aftermarket devices, or intermittent conditions are not the cause, begin the system diagnosis with the Vehicle Diagnostic System Check. The Vehicle Diagnostic System Check will provide the following information

1. The identification of the control modules that control the Power Steering System.
2. The ability of those control modules to communicate via the serial data circuit.
3. The presence of any stored diagnostic trouble codes (DTCs) in those control modules and there status.

The use of the Vehicle Diagnostic System Check will identify the correct procedure for diagnosing the malfunction and where the procedure is located. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information.

Scan Tool Data List

Scan Tool Data List

Scan Tool Data Definitions

Circuit Description

The power steering control module (PSCM) receives a vehicle speed message from the engine control module (ECM) via the class 2 serial data circuit. The PSCM uses this vehicle speed message, and other inputs, to determine the desired amount of steering assist.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC C0000 - Vehicle Speed Information Circuit

Conditions for Running the DTC

1. The ignition is ON.
2. DTC U1300, U1301, or U2100 are not set.
3. Vehicle speed is greater than 8.1 km/h (5 mph).

Conditions for Setting the DTC

The PSCM receives an invalid, or no vehicle speed message from the ECM.

Action Taken When the DTC Sets

1. DTC C0000 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. Steering assist level defaults to 120 km/h (74.5 mph) vehicle speed level of assist.

Conditions for Clearing the DTC

1. A current DTC will clear on the next malfunction free ignition cycle.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Tests for the presence of vehicle speed related DTCs in the control modules where the vehicle speed message originates.

DTC C0000

The power steering control module (PSCM) continuously monitors the voltage and current levels being commanded to the electric power steering (EPS) motor. The PSCM compares the desired and actual current levels to detect malfunctions in the EPS motor, or the circuits to the motor.

This diagnostic procedure supports the following DTC

DTC C0475 - Electric Steering Motor Circuit

1. The ignition is ON.
2. No voltage DTCs are present.

The actual motor current does not equal the desired motor current.

1. DTC C0475 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warring message.
3. No steering assist is provided.

1. A current DTC will clear on the next malfunction free ignition cycle.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

DTC C0475

The power steering control module (PSCM) monitors the temperature of the electric power steering (EPS) system. The PSCM uses voltage and current levels to calculate an estimated system temperature. If the PSCM detects a high system temperature, the amount of assist is reduced to lower the EPS system temperature to prevent thermal damage to the system.

This diagnostic procedure supports the following DTC

DTC C0476 - Electric Steering Motor Range/Performance

Condition for Running the DTC

The ignition is ON.

The PSCM detects a high system temperature.

1. A DTC C0476 is stored in memory.
2. Steering assist is reduced.

1. A current DTC will clear when the EPS system temperature returns to normal.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

Diagnostic Aids

1. DTC C0476 does not indicate that a malfunction has occurred. DTC C0476 indicates that the PSCM had to limit current to the EPS motor to avoid system thermal damage.
2. Inspect the area around the EPS assembly. Ensure that no other components have come in contact with the EPS assembly such as insulation or other electrical components.
3. Ensure that no steering components, such as ball joints, tie rod ends, universal joints, or the steering rack and pinion are mechanically binding.
4. Inspect for aftermarket items that may increase the amount of steering assist required.

The number below refer to the step number on the diagnostic table.

1. 2: Tests if the high system temperature is system, or driving condition related. Most occurrences of the DTC are caused by frequent static steering, such as parking maneuvers and high ambient temperatures

DTC C0476

The electric power steering (EPS) system uses a torque sensor to detect the amount of torque being applied to the steering column shaft when the steering wheel is turned. The power steering control module (PSCM) uses this sensor as it's main input in determining the amount of steering assist needed.

This diagnostic procedure supports the following DTC

DTC C0545 - Steering Wheel Torque Input Sensor

The ignition, and the engine are ON.

Condition for Setting the DTC

1. The PSCM's torque sensor input is greater than 20.70 N.m (15.2 lb ft) during a right turn.
2. The PSCM's torque sensor input is less than -20.70 N.m (15.2 lb ft) during a left turn.
3. The difference between the 2 torque sensor coils is greater than 2.4 N.m (1.7 lb ft).

1. A DTC C0545 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. No steering assist is provided.

1. A current DTC will clear on the next malfunction free ignition cycle.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

The torque sensor is hard wired to the PSCM. No connector, or circuit testing can be performed. if an intermittent malfunction is suspected with the torque sensor, or the circuits to the torque sensor, replace the EPS assembly. Refer to Steering Column Replacement in Steering Wheel and Column. The scan tool can be used to view the torque sensor value.

The number below refers to the step number on the diagnostic table.

1. 2: Tests the torque sensor in its active state.

DTC C0545

After replacement of the electric power steering (EPS) assembly, the power steering control module (PSCM) must be configured with the proper tuning profile using the service programming system.

This diagnostic procedure supports the following DTC

DTC C0551 Option Configuration Error

The ignition is ON.

The PSCM has not been configured with the proper tuning profile.

1. DTC C0551 is stored in memory.
2. The instrument panel cluster (IPC) displays the SERVICE VEHICLE SOON warning indicator.
3. Steering assist is set to a default level.

1. A current DTC will clear after the PSCM has been configured with the proper tuning profile.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles after the PSCM has been configured.

A newly replaced EPS assembly will set DTC C0551 on it's initial ignition ON cycle.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Tests if the condition is current.

DTC C0551

The body control module (BCM) contains the 2 amp EPS fuse. This fuse and the ignition 1 voltage circuit supply ignition voltage to the power steering control module (PSCM). This ignition voltage is used to wake up the PSCM.

This diagnostic procedure supports the following DTC

DTC C0847 - Device 1 Ignition Circuit Low

The ignition is ON.

1. The ignition 1 voltage circuit is shorted to ground or open.
2. DTCs U1300 and U1301 are not set.

1. DTC C0847 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. The EPS system is disabled.

1. A current DTC will clear when the malfunction is no longer present.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

The Ignition 1 voltage circuit supplies several other control modules with ignition voltage. Before preceding with the diagnostic table below, ensure no other control modules that use the ignition 1 circuit for their ignition voltage supply have any ignition voltage malfunctions present, such as the sensing and diagnostic module (SDM), or the cruise control module (CCM). Refer to Power Distribution Schematics in Wiring Systems. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems for further diagnosis.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Tests if the malfunction is intermittent.
2. 5: Tests if a short to ground exists in the ignition 1 voltage circuit, or in the PSCM.

DTC C0847

The power steering control module (PSCM) receives a class 2 power mode message from the body control module (BCM) to determine the position of the ignition switch. After a power mode OFF message is received, the PSCM monitors the ignition 1 voltage circuit to detect if a short to voltage exists.

This diagnostic procedure supports the following DTC

DTC C0848 - Device 1 Ignition Circuit High

1. The ignition is OFF.
2. The class 2 power mode message indicates OFF.

1. The PSCM ignition 1 voltage circuit is shorted to voltage.
2. DTCs U1300 and U1301 are not set.

1. DTC C0848 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.

Conditions for Clearing the MIL/DTC

1. A current DTC will clear on the next consecutive malfunction free ignition cycle.
2. A history DTC will clear after 100 consecutive malfunction free ignition cycles.

DTC C0848

The power steering control module (PSCM) has a discrete battery positive voltage supply circuit. The PSCM monitors the voltage level on this circuit to ensure the electric power steering (EPS) system has adequate voltage levels to perform the system functions.

This diagnostic procedure supports the following DTC

DTC C0896 Device Voltage Range/Performance

The ignition is ON.

EPS system battery voltage is 9-11 volts.

1. DTC C0896 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. Steering assist is reduced.

1. A current DTC will clear when EPS system voltage is greater than 11 volts.
2. A history DTC will clear after 100 consecutive ignition cycles with EPS system voltage greater than 11 volts.

The scan tool can be used to view the number of times a low battery voltage incident has occurred. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems for further diagnosis.

The number below refers to the step number on the diagnostic table.

1. 2: Tests if the malfunction exists in the vehicles charging system.
2. 3: Tests if the malfunction is intermittent.

DTC C0896

The power steering control module (PSCM) has a discrete battery positive voltage supply circuit. The PSCM monitors the voltage level on this circuit to ensure the electric power steering (EPS) system has adequate voltage levels to perform the system functions. If the voltage level is low, DTC C0899 sets.

This diagnostic procedure supports the following DTC

DTC C0899 Device 1 Voltage Low

The ignition is ON.

EPS system voltage is less than 8 volts

1. DTC C0899 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. No steering assist is provided.

1. A current DTC will clear when EPS system voltage is greater than 8.65 volts.
2. A history DTC will clear after 100 consecutive ignition cycles with the EPS system voltage greater than 8.65 volts.

The scan tool can be used to view the number of times a low battery incident has occurred. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems for further diagnosis.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Tests if the malfunction exists in the vehicles charging system.
2. 3: Tests if the malfunction is in the EPS system.

DTC C0899

The power steering control module (PSCM) has a discrete battery voltage supply circuit. The PSCM monitors the voltage level on this circuit to protect itself against high voltage damage.

This diagnostic procedure supports the following DTC

DTC C0900 Device 1 Voltage High

The ignition is ON.

EPS system voltage is greater than 17 volts.

1. DTC C0900 is stored in memory.
2. The instrument panel cluster (IPC) message center displays the PWR STR warning message.
3. The PSCM is disabled to protect itself.

1. A current DTC will clear when the EPS system voltage returns to less than 15.5 volts.
2. A history DTC will clear after 100 consecutive ignition cycles with the EPS system voltage less than 15.5 volts.
3. Using a scan tool

Jump starting the vehicle can cause DTC C0900 to set. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems for further diagnosis.

DTC C0900

1. Inspect for aftermarket devices which could affect the operation of the power steering system.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Rattle, Clunk, or Shudder Noise from the Power Steering System»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system)
2. «Increase in Effort While Turning Steering Wheel»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system__increase-in-effort-while-turning-steering)
3. «Poor Return of Steering Wheel»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system__poor-return-of-steering-wheel)
4. «Steering Wheel Surges/Jerks While Turning»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system__steering-wheel-surgesjerks-while-turning)

Rattle, Clunk, or Shudder Noise from the Power Steering System

Increase in Effort While Turning Steering Wheel

Increase in Effort While Turning Steering Wheel

Poor Return of Steering Wheel

Poor Return of Steering Wheel

Steering Wheel Surges/Jerks While Turning

Steering Wheel Surges/Jerks While Turning

Tools Required

J 24319-B Steering Linkage and Tie Rod Puller

Removal Procedure

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/equinox/i-2004-2009/remont/hoistjack/#general-information) in General Information.
2. Remove the front tire assembly. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Loosen the tie rod inner jam nut.
4. Remove the tie rod to knuckle nut. Discard the nut.
5. Use the J 24319-B to separate the tie rod from the steering knuckle.
6. Remove the outer tie rod from the inner tie rod.

Installation Procedure

1. Install the outer tie rod to the inner tie rod.
2. Connect the tie rod to the knuckle.
3. Install a new tie rod retention nut. Tighten: Tighten the nut to 60 N.m (44 lb ft).
4. Install the front tire assembly. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
5. Check the wheel alignment. Refer to «Measuring Wheel Alignment»(/chevrolet/equinox/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.

J 22610 Keystone Clamp Pliers. See Special Tools .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/equinox/i-2004-2009/remont/hoistjack/#general-information) in General Information.
2. Remove the tire assembly. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Remove the outer tie rod. Refer to «Rack and Pinion Outer Tie Rod End Replacement»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system) .
4. Remove the jam nut.
5. Remove the spring from the boot, outer end.
6. Cut and remove the crimp clamp, inner end. Discard the clamp.
7. Unseat the boot from the steering gear and remove.
8. Clean the inner tie rod and boot contact area of grease and debris.

1. Apply approximately 3/4 of the supplied grease packet into the small end of the boot cavity. Apply the remainder of the grease on the shaft where the small end of the boot meats the shaft.
2. Install the boot with the large clamp loosely attached, not crimped.
3. Using the J 22610 , crimp the large clamp. See «Special Tools»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system__special-tools) .
4. Install the spring clamp to the small end of the boot.
5. Install the jam nut approximately 174 mm (6.85 in) from the boot clamp.
6. Install the outer tie rod. Refer to «Rack and Pinion Outer Tie Rod End Replacement»(/chevrolet/equinox/i-2004-2009/remont/manual-power-steering/#power-steering-system) .
7. Install the tire assembly. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
8. Check the front wheel alignment and align as necessary. Refer to «Measuring Wheel Alignment»(/chevrolet/equinox/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.

J 24319-B Steering Linkage and Tie Rod Puller

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/equinox/i-2004-2009/remont/hoistjack/#general-information) in General Information.
2. Remove the front tires. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Remove both outer tie rod to steering knuckle nuts. Discard the nuts.
4. Using the J 24319-B , separate the tie rods from the steering knuckles.
5. Rotate the intermediate steering shaft in order to gain access to the intermediate shaft pinch bolt.
6. Remove the intermediate to steering gear pinch bolt. Discard the bolt.
7. Disconnect the intermediate shaft from the steering gear.
8. Disconnect the stabilizer links from the stabilizer bar. Refer to «Stabilizer Shaft Link Replacement»(/chevrolet/equinox/i-2004-2009/remont/suspension-front/#front-suspension-system) in Front Suspension.
9. Remove the steering gear to cradle mounting bolts.
10. Remove the steering gear through the right side of the vehicle.
11. With heat shield equipped steering gears, remove the heat shield. Save for installation.

1. If applicable, install the heat shield.
2. Install the steering gear from the right side of the vehicle.
3. Center the gear mounting bushings into the cradle supports.
4. Hand start both steering gear to cradle mounting bolts. Tighten: Tighten the bolts to 110 N.m (81 lb ft).
5. Connect the intermediate shaft to the steering gear and install a new pinch bolt. Tighten: Tighten the intermediate pinch bolt to 34 N.m (25 lb ft).
6. Connect the stabilizer links to the stabilizer bar. Refer to «Stabilizer Shaft Link Replacement»(/chevrolet/equinox/i-2004-2009/remont/suspension-front/#front-suspension-system) in Front Suspension.
7. Connect the tie rod to the knuckle and install a new nut. Tighten: Tighten the nut to 60 N.m (44 lb ft).
8. Install the front tires and wheels. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/equinox/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
9. Check the front wheel alignment and align as necessary. Refer to «Measuring Wheel Alignment»(/chevrolet/equinox/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.
10. Lower the vehicle.

The electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle. The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions. The PSCM, torque sensor, nor the EPS motor are serviced separately from each other or from the steering column. Ant EPS components diagnosed to be malfunctioning requires replacement of the steering column assembly, also known as the EPS assembly.

Torque Sensor

The PSCM uses a torque sensor as it's main input for determining the amount of steering assists. The steering column has an input shaft, from the steering wheel to the torque sensor, and an output shaft, from the torque sensor to the steering shaft coupler. The input and output shafts are separated by a torsion bar, where the torque sensor is located. The sensor consists of a compensation coil, detecting coil, and 3 detecting rings. These detecting rings have toothed edges that face each other. Detecting ring 1 is fixed to the output shaft, detecting rings 2 and 3 are fixed to the input shaft. The detecting coil is positioned around the toothed edges of detecting rings 1 and 2. As torque is applied to the steering column shaft the alignment of the teeth between detecting rings 1 and 2 changes, which causes the detecting coil signal voltage to change. The PSCM recognizes this change in signal voltage as steering column shaft torque. The compensation coil is used to compensate for changes in electrical circuit impedance due to circuit temperature changes from electrical current and voltage levels as well as ambient temperatures for accurate torque detection.

EPS Motor

The EPS motor is a 12 volt brushed DC reversible motor with a 65 amp rating. The motor assists steering through a worm shaft and reduction gear located in the steering column housing.

Power Steering Control Module (PSCM)

The PSCM uses a combination of torque sensor inputs, vehicle speed, calculated system temperature and the steering calibration to determine the amount of steering assist. When the steering wheel is turned, the PSCM uses signal voltage from the torque sensor to detect the amount of torque being applied to the steering column shaft and the amount of current to command to the EPS motor. The PSCM receives serial data from the engine control module (ECM) to determine vehicle speed. At low speeds more assist is provided for easy turning during parking maneuvers. At high speeds, less assist is provided for improved road feel and directional stability. The PSCM nor the EPS motor are designed to handle 65 amps continuously. The PSCM will go into overload protection mode to avoid system thermal damage. In this mode the PSCM will limit the amount of current commanded to the EPS motor which reduces steering assist levels. The PSCM also chooses which steering calibration to use when the ignition is turned ON, based on the VIN. The PSCM contains all 8 of the steering calibrations which are different in relation to the vehicles RPO's. The PSCM has the ability to detect malfunctions within the EPS system. Any malfunction detected will cause the IPC message center to display the PWR STR (or Power Steering) warning message.

Special Tools

Special Tools Illustration Tool Number/ Description J 22610 Keystone Clamp Pliers J 24319-B Steering Linkage and Tie Rod Puller J 44015 Steering Linkage Installer

Scheme 4

Scheme 5

Scheme 6

See also:
• Testing for Intermittent Conditions and Poor Connections
• Steering Column Accident Damage Inspection
• Diagnostic System Check - Vehicle
• Diagnostic Trouble Code (DTC) List - Vehicle
• Connector Repairs
• Circuit Testing
• Wiring Repairs
• Testing for a Short to Voltage
• Control Module References
• Power Distribution Schematics
• Testing for Short to Ground
• Symptoms - Engine Electrical
• Symptoms - Steering Wheel and Column
• Noise Diagnosis - Front Suspension
• Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID
• Measuring Wheel Alignment
• Lower Ball Joint Replacement
• Diagnostic Starting Point - Engine Electrical
• Tire and Wheel Removal and Installation
• Fastener Notice
• DTC C0000
• Increase in Effort While Turning Steering Wheel
• Poor Return of Steering Wheel
• Steering Wheel Surges/Jerks While Turning
• Special Tools