Power Steering System GMC Sierra 2500

Fastener Tightening Specifications

Fastener Tightening Specifications

Power Steering Pump Specifications

Power Steering Pump Specifications

Adhesives, Fluids, Lubricants, and Sealers

Adhesives, Fluids, Lubricants, and Sealers

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

The PSCM uses a combination of commanded motor voltage and current levels to calculate an estimated power steering system temperature. If the PSCM detects a high system temperature event is occurring, the amount of assist is reduced to lower system temperature to prevent thermal damage to the power steering components.

Condition for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The PSCM detects a high system temperature.

Action Taken When the DTC Sets

1. DTC C0176 54 is stored in memory.
2. Steering assist is reduced.

Conditions for Clearing the DTC

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

Diagnostic Aids

1. DTC C0176 54 does not indicate that a malfunction has occurred. Rather that the PSCM had to limit current to the power steering motor to avoid thermal damage to the power steering system components.
2. Ensure that no steering components down stream of the power steering gear assembly, universal joints, ball joints or tie rod ends are mechanically binding.

Reference Information

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide overview of each diagnostic category.

Diagnostic Fault Information

The power steering control module (PSCM) continuously monitors the motor rotational sensor sinusoidal voltage signals. The sinusoidal voltage signals of the motor rotational sensor and the angle difference between the steering output and input shafts detected by the torque sensor are both processed by the PSCM to detect and calculate the steering wheel angle.

Conditions for Running the DTC

Ignition ON.

1. The PSCM detects open, short to ground or short between any of the motor rotational sensor circuits.
2. The PSCM detects the steering wheel angle is outside the valid range of -720 to +720 degrees.

Actions Taken When DTC Sets

1. DTC C0460 00 is stored in memory.
2. The driver information center (DIC) displays the SERVICE POWER STEERING message.
3. No steering assist.

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.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Engine running, then center the steering wheel, observe the scan tool Steering Wheel Position parameter, the reading should be 0 +/- 10 degrees.

1. If not within the specified range, perform the steering position torque sensor calibration, and verify DTC C0460 is not set as current.

Circuit/System Testing

Note. After verifying a circuit fault exists in the Power Steering Wiring Harness Extension Harness for Two Mode Hybrid. The wiring harness is to be replaced and not repaired.

1. Perform the «High Voltage Disabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
2. Ignition OFF, connect the 12-volt battery.
3. Ignition OFF, disconnect the X3 harness connector at the PSCM.
4. Test for 3K-10K ohms between the rotational sensor low reference circuit terminal 1 and the rotational sensor signal circuit terminal 7. If not within the specified range, test the signal circuit and the low reference circuit for an open/high resistance or a short together. If the circuits test normal, replace the power steering assist motor.
5. Test for 6K-20K ohms between the rotational sensor low reference circuit terminal 1 and the rotational sensor signal circuit terminal 8. If not within the specified range, test the rotational sensor signal circuit and the rotational sensor low reference circuit for an open/high resistance or a short together. If the circuits test normal, replace the power steering assist motor.
6. Test for 10-200ohms between the low reference circuit terminal 1 and the 5V reference circuit terminal 3. If not within the specified range, test the 5V reference circuit and the low reference circuit for an open/high resistance or a short together. If the circuits test normal, replace the power steering assist motor.
7. Test for greater than infinite resistance between the rotational sensor exciting ground circuit terminal 3 and the EPS motor housing. If less than the specified range, test the appropriate circuit for a short to ground. If the circuits test normal, replace the power steering assist motor.
8. If all circuits test normal, test or replace the PSCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Steering Wiring Harness Extension Harness Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
2. «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
3. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PSCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide overview of each diagnostic category.

The power steering control module (PSCM) continuously monitors the voltage and current levels being commanded to the electric power steering (EPS) motor. The 42-volt circuit from the accessory power module (APM) supplies power to the PSCM pulse width modulated command circuit to drive the brushless, 3 phase motor. The PSCM compares the desired and actual current levels to detect malfunctions in the EPS motor, or the circuits to the motor.

Ignition ON.

The PSCM detects an open, or a short to ground on any of the motor phase circuits.

1. The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
2. No steering assist.

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.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. After verifying a circuit fault exists in the Power Steering Assist Motor Wiring Harness for Two Mode Hybrid, the Power Steering Assist Motor is to be replaced and not repaired

1. Perform the «High Voltage Disabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
2. Ignition OFF, connect the 12-volt battery.
3. Ignition OFF, disconnect the harness connector at the PSCM.
4. Test for less than 1 ohm between the following circuits listed below. Phase terminal 2 and phase terminal 1 Phase terminal 1 and phase terminal 3 Phase terminal 2 and phase terminal 3 If greater than the specified range, replace the power steering assist motor.
5. Test for greater than infinite resistance between the following circuits listed below and the power steering motor housing. Phase terminal 2 Phase terminal 1 Phase terminal 3 If less than the specified range, replace the power steering assist motor.
6. If all circuits test normal, test or replace the PSCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PSCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power steering control module (PSCM) continuously monitors the torque sensor's input and output shaft sinusoidal voltage signals. As the steering wheel is turned and torsional twist is applied to the steering shaft, the torque sensor's input and output shaft sinusoidal voltage signals are processed by the PSCM to detect and calculate the steering torque.

Ignition ON.

1. The PSCM detects open, short to ground or short between any of the torque sensor circuits.
2. The PSCM detects the steering torque is outside the valid range of -7 to +7 N.m.

1. DTC C0545 is stored in memory.
2. The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
3. No steering assist.

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.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. After verifying a circuit fault exists in the Power Steering Wiring Harness Extension Harness for Two Mode Hybrid. The wiring harness is to be replaced and not repaired.

1. Perform the «High Voltage Disabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
2. Ignition OFF, connect the 12-volt battery.
3. Ignition OFF, disconnect the X3 harness connector at the PSCM.
4. Test for 2-20 ohms between the torque sensor signal circuit terminal 4 and the torque sensor low reference circuit terminal 6. If not within the specified range, test the appropriate circuits for a short to ground, an open/high resistance, or a short together. If the circuits test normal, replace the power steering gear.
5. Test for 100-500 ohms between the torque sensor signal circuit terminal 10 and the torque sensor low reference circuit terminal 9. If not within the specified range, test the appropriate circuits for an open/high resistance, or a short together. If the circuits test normal, replace the power steering gear.
6. Test for 300-1000 ohms between the torque sensor signal circuit terminal 11 and the torque sensor low reference circuit terminal 9. If not within the specified range, test the appropriate circuits for an open/high resistance, or a short together. If the circuits test normal, replace the power steering gear.
7. Test for 50-200 ohms between the torque sensor signal circuit terminal 12 and the torque sensor low reference circuit terminal 9. If not within the specified range, test the appropriate circuits for an open/high resistance, or a short together. If the circuits test normal, replace the power steering gear.
8. Test for 200-800 ohms between the torque sensor signal circuit terminal 13 and the torque sensor low reference circuit terminal 9. If not within the specified range, test the appropriate circuits for an open/high resistance, or a short together. If the circuits test normal, replace the power steering gear.
9. Test for infinite resistance between the torque sensor low reference terminal 6 and torque sensor low reference terminal 9. If less than the specified value, test the appropriate circuit for a short together. If the circuits test normal, replace the power steering gear.
10. Test for greater than infinite resistance between the following circuits listed below and the EPS motor housing. Torque sensor low reference terminal 9 Torque sensor low reference terminal 6 If less than the specified range, test the appropriate circuit for a short to ground. If the circuits test normal, replace the power steering gear.
11. If all circuits test normal, test or replace the PSCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Steering Wiring Harness Extension Harness Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
2. «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
3. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PSCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The PSCM monitors vehicle speed validity message from the engine control module (ECM) via the serial data circuit. The power steering control module (PSCM) uses this vehicle speed message, along with the torque sensor and motor rotational sensor inputs, to determine the desired amount of steering assist.

The PSCM monitors the intermediate voltage power limit request message from the accessory power module (APM) to detect a possible overheating event. The hybrid control module (HCM) sends this message to the PSCM via the serial data gateway module to reduce the APM power output to the PSCM until the APM returns to normal operating temperature.

Ignition ON.

C0561 71

The PSCM receives an invalid, vehicle speed message from the ECM.

C0561 76

The PSCM receives the intermediate voltage power limit request message to ramp down the power assist due to a possible APM overheating event.

1. DTC is stored in memory.
2. The driver information center (DIC) displays the SERVICE POWER STEERING warning message.

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.
3. Steering assist is reduced.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify that no DTCs are set in the ECM or APM.

1. If DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list)

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The power steering control module (PSCM) continuously monitors the internal circuitry within the module.

Ignition ON.

This DTC will set if the PSCM detects an internal malfunction within the module.

1. DTC C056D is stored in memory.
2. The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
3. No steering assist.

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, without the repeat of the internal malfunction.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. Verify the motor connector is securely connected and not loose.

Verify that DTC C056D is not set.

1. If the DTC is set, replace the PSCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PSCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

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

After replacement of the PSCM, power steering motor, or steering gear, the steering position/torque sensor calibration procedure must be performed.

Ignition ON.

C056E 42

This DTC will set if the PSCM has not undergone SPS programming.

C056E 4B

This DTC will set if the PSCM, motor or torque sensor has not been calibrated using the steering position / torque sensor calibration procedure.

1. DTC is stored in memory.
2. The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
3. Steering assist is set to a default level.

C056E 42

A current or history DTC will clear after the PSCM has been configured with the proper tuning profile.

C056E 4B

A current or history DTC will clear after the steering position/torque sensor calibration procedure has been performed.

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Steering System Description and Operation (EPS) , Power Steering System Description and Operation (Hydraulic Power Steering)

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify DTC C056E 42 is not set. If DTC C056E 42 is set, perform the PSCM programming and setup procedures. If DTC C056E 42 resets, replace the PSCM.
2. Verify DTC C056E 4B is not set. If DTC C056E 4B is set, perform the steering position/torque sensor calibration. If DTC C056E 4B resets, replace the PSCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PSCM replacement, setup, and programming

Visual/Physical Inspection

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.
3. Inspect for leaking power steering components. If necessary, refer to «Power Steering Fluid Leaks»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-fluid-leaks) .
4. Verify the power steering reservoir for the proper operating specification. Refer to «Checking and Adding Power Steering Fluid (Without Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) , «Checking and Adding Power Steering Fluid (With Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) .
5. Inspect the power steering fluid for the following indications of contamination: Milky fluid - water Brown fluid - burnt Debris in fluid - plastic or dirt
6. If necessary, flush the power steering system. Refer to «Power Steering System Flushing»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Symptoms List

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

1. «Power Steering Fluid Leaks»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-fluid-leaks)
2. «Rattle, Clunk, or Shudder Noise from the Power Steering System (Without HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Rattle, Clunk, or Shudder Noise from the Power Steering System (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
3. «Whine or Growl Noise from the Power Steering System (With Hydraulic Booster)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Whine or Growl Noise from the Power Steering System (Two-Mode)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Whine or Growl Noise from the Power Steering System (Without Hydraulic Booster)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system)
4. «Poor Return of Steering Wheel»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__poor-return-of-steering-wheel)
5. «Steering Effort Hard in One or Both Directions (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-effort-hard-in-one-or) , «Steering Effort Hard in One or Both Directions (Standard)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-effort-hard-in-one-or)
6. «Steering Effort Too Easy in One or Both Directions»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-effort-too-easy-in-one)

Scheme 8

Scheme 9

Test Description

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

1. 5 This step tests the system for restrictions.
2. 7 This step tests the following components for the following conditions: The pump for internal leaks NOTE: Power steering hoses may not look kinked, but have a layer separation causing the inner hose to collapse and restrict power steering fluid flow. The power steering pipes and hoses for kinks
3. 8 This step tests the ability of the pump to regulate flow at maximum pressure.
4. 10 This step tests the ability of the pump to regulate flow under normal operating conditions.
5. 12 This step tests the internal components of the pump and the gear.

Power Steering System Test

Power Steering Fluid Leaks

Special Tools

GE-28431-6 Fluorescent Dye

For equivalent regional tools, refer to Special Tools .

Note. If fluid is found on a manual steering gear or on an electronic power steering gear, do not replace steering gear. Vehicles equipped with these systems do not use hydraulic power steering fluid. The fluid may be assembly fluid or another system fluid. Clean the components and identify the sources of the leaks before attempting to repair or replace any power steering components. Clearly mark all locations of leaks with paint, marker, or equivalent for warranty identification and engineering root cause analysis.

Some customers may comment on a fluid LEAK or NOISY power steering pump. Upon inspection, the technician may find power steering fluid leaking from the hydraulic power steering system. Use the following inspection procedure in order to diagnose the source of the leak and take appropriate action to correct the condition.

1. Inspect the fluid level in the power steering fluid reservoir. Refer to «Checking and Adding Power Steering Fluid (Without Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) , «Checking and Adding Power Steering Fluid (With Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) . If the fluid level is NOT low, a careful analysis of the condition is necessary to confirm that the type of fluid is actually power steering fluid.
2. Visually inspect the power steering system and components where the fluid has accumulated.
3. Use a clean towel or a rag in order to completely clean off all residual fluid from the power steering components.
4. Add 30 cc (1 oz) of GE-28431-6 dye to the power steering fluid.
5. Start the vehicle and warm the steering system by turning to the left steering stop and to the right steering stop 10 times with the weight of the vehicle on the front tires.
6. Turn vehicle engine OFF.
7. Shine a black light on the area where the residual fluid accumulated. Identify the sources of the leaks. If equipped with hydroboost, refer to «Hydraulic Brake Booster Leak Inspection»(/gmc/sierra-2500/2012-2012/remont/mechanical-hydraulic/#hydraulic-brake-system) .
8. Mark all locations of leaks with paint, marker, or equivalent.
9. Repair or replace all affected components.

Rattle, Clunk, or Shudder Noise from the Power Steering System (Without HP2)

Rattle, Clunk, or Shudder Noise from the Power Steering System (HP2)

Whine or Growl Noise from the Power Steering System (Without Hydraulic Booster)

Whine or Growl Noise from the Power Steering System (Two-Mode)

Whine or Growl Noise from the Power Steering System (With Hydraulic Booster)

Poor Return of Steering Wheel

Poor Return of Steering Wheel

Steering Effort Too Easy in One or Both Directions

Steering Effort Too Easy in One or Both Directions

Steering Effort Hard in One or Both Directions (Standard)

Steering Effort Hard in One or Both Directions (Standard)

Steering Effort Hard in One or Both Directions (HP2)

Steering Effort Hard in One or Both Directions (HP2)

Steering Linkage Inner Tie Rod Inspection

Special Tools

J-8001 Dial Indicator Set

For equivalent regional tools, refer to Special Tools .

1. Turn the ignition key to the ON position with the engine OFF.
2. With the aid of an assistant, turn the steering wheel to the full stop position and hold the steering wheel in that position until the test is complete. The tie rod being tested should be inside the steering gear housing seated against the steering stop.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
4. If there is not a good location for the J-8001 Dial Indicator pointer at the steering gear housing, install a large worm gear hose clamp to the steering gear housing over the larger steering gear boot clamp and align the clamp so that the screw can be a location for the J-8001 Dial Indicator pointer.
5. Install the J-8001 Dial Indicator between the inner tie rod (2) and the steering gear housing or the worm gear clamp in such a way as to measure the lash between the inner tie rod and the steering gear housing.
6. Grasping the tire at the 3 o'clock (2) and 9 o'clock (1) positions, gently push in on one side of the tire in order to remove any lash.
7. Zero the J-8001 Dial Indicator.
8. On the same side of the tire previously pushed in, gently pull out and measure the lash.
9. Record the measurement seen on the J-8001 Dial Indicator.
10. If the measured value exceeds 0.5 mm (0.02 in), replace the inner tie rod. Refer to «Steering Linkage Inner Tie Rod Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Linkage Inner Tie Rod Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-linkage-inner-tie-rod-replacement) .
11. Repeat the procedure for the other side.

Steering Linkage Outer Tie Rod Inspection

Special Tools

J-8001 Dial Indicator Set

For equivalent regional tools, refer to Special Tools .

1. Inspect the outer tie rod end seal. If the outer tie rod end seal is torn, replace the outer tie rod end. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Raise the side of the vehicle being inspected with a floor jack while maintaining contact between the opposite wheel and the shop floor. Support the lower control arm with a floor jack stand as far outboard as possible and remove the floor jack. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
3. Install the J-8001 Dial Indicator between the outer tie rod end and the steering knuckle as shown in the graphic. Note that the tire and wheel assembly is shown removed only for clarification of the dial indicator position.
4. Grasping the tire at the 3 o'clock (2) and 9 o'clock (1) positions, gently push in on one side of the tire to remove any lash.
5. Zero the J-8001 Dial Indicator.
6. On the same side of the tire previously pushed inwards, gently pull outwards and measure the lash.
7. Record the measurement seen on the J-8001 Dial Indicator.
8. If the measured value exceeds 1 mm (0.04 in) then replace the outer tie rod. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
9. Repeat the procedure for the other side.

1. Fill pump reservoir with fluid to minimum system level, FULL COLD level, or middle of hash mark on cap stick fluid level indicator.
2. If equipped with hydro-boost, fully charge the hydro-boost accumulator using the following procedure: Start the engine. Firmly apply the brake pedal 10-15 times. Turn the engine OFF.
3. Raise the vehicle until the front wheels are off the ground. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
4. Key on engine OFF, turn the steering wheel from stop to stop 12 times. Vehicles equipped with hydro-boost systems or longer length power steering hoses may require turns up to 15 to 20 stop to stops.
5. Verify power steering fluid level per operating specification. Refer to «Checking and Adding Power Steering Fluid (Without Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) , «Checking and Adding Power Steering Fluid (With Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) .
6. Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).
7. Verify the fluid level. Repeat the bleed procedure, if necessary.

Checking and Adding Power Steering Fluid (Without Hydroboost)

1. Clean the area surrounding the reservoir cap.
2. Remove the reservoir cap.
3. Inspect the power steering pump fluid level at regular intervals. Use the appropriate procedure below. Add fluid when required. Refer to «Fluid and Lubricant Recommendations»(/gmc/sierra-2500/2012-2012/remont/lubrication-system/#maintenance-and-lubrication__fluid-and-lubricant-recommendations) . Fluid Is Cold Remove the reservoir cap. Inspect the fluid level on the capstick. Ensure that the fluid level is between the bottom of the COLD/FULL mark and the end of the capstick. Fluid Is Hot Run the engine until the fluid reaches about 80°C (170°F). Turn the engine OFF. Remove the reservoir cap. Inspect the fluid level on the capstick. Ensure that the fluid level is between the HOT/FULL and the COLD/FULL marks on the capstick.
4. If the fluid level is low, add power steering fluid to the proper level.
5. Install the reservoir cap.
6. When checking the fluid level after servicing the steering system, bleed the air from the system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Checking and Adding Power Steering Fluid (With Hydroboost)

1. If the power steering system has been serviced, bleed the power steering system to remove any trapped air from the system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Fully charge the hydro-boost accumulator using the following procedure: Start the engine. Firmly apply the brake pedal 2 to 3 times. Turn the engine OFF.
3. Clean the area surrounding the reservoir cap.
4. Remove the reservoir cap.
5. Inspect the power steering pump fluid level at regular intervals. Add fluid when required. Refer to «Fluid and Lubricant Recommendations»(/gmc/sierra-2500/2012-2012/remont/lubrication-system/#maintenance-and-lubrication__fluid-and-lubricant-recommendations) .
6. Install the reservoir cap.
7. When checking the fluid level after servicing the steering system, bleed the air from the system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Note. Do not reuse any drained power steering fluid regardless of appearance or condition.

1. Raise the vehicle until the front wheels are off the ground. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Place a large drain pan under the vehicle in order to collect the draining fluid.
3. Remove the fluid return hose at the power steering fluid reservoir or the pump inlet connection, as applicable.
4. Plug the reservoir return hose inlet connection on the power steering fluid reservoir or the pump, as applicable.
5. Have an assistant maintain the minimum fluid level in the reservoir using clean, new power steering fluid. Refer to «Checking and Adding Power Steering Fluid (Without Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) , «Checking and Adding Power Steering Fluid (With Hydroboost)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__checking-and-adding-power-steering-fluid) .
6. With the key in the ON position and with the engine OFF, turn the steering wheel fully to the left and to the right. Continue until the fluid from the return hose runs clear.
7. Remove the plug and install the fluid return hose to the power steering fluid reservoir or the pump inlet connection, as applicable.
8. Bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
9. Inspect the power steering fluid for the following indications of contamination: Milky fluid - water Brown fluid - burnt Plastic debris or dirt chunks
10. If the fluid is contaminated, repeat steps 3-9.
11. Remove the drain pan.
12. Lower the vehicle.

Special Tools

1. J-25033-C Pulley Installer
2. J-25034-C Pulley Remover

For equivalent regional tools, refer to Special Tools .

Removal Procedure

1. Remove the accessory drive belt. Refer to «Drive Belt Replacement»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-66l-lgh-lml-repair-instructions-on-vehicle) .
2. Use the J-25034-C remover in order to remove the power steering pump pulley.

Installation Procedure

1. Place the power steering pump pulley on the end of the power steering pump shaft.
2. Use the J-25033-C installer in order to install the power steering pump pulley.
3. Ensure that the power steering pump pulley (1) is flush against the power steering pump shaft (2) with an allowable variance of 0.25 mm (0.010 in).
4. Install the accessory drive belt. Refer to «Drive Belt Replacement»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-66l-lgh-lml-repair-instructions-on-vehicle) .

Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)

Special Tools

1. J-25033-C Pulley Installer
2. J-25034-C Pulley Remover

For equivalent regional tools, refer to Special Tools .

1. Remove the engine coolant fan upper shroud, if equipped. Refer to «Engine Coolant Fan Upper Shroud Replacement (Diesel)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-48l-53l-60l-62l-repair-instructions-on-vehicle) .
3. Use the J-25034-C remover in order to remove the power steering pump pulley.

1. Place the power steering pump pulley on the end of the power steering pump shaft.
2. Use the J-25033-C installer in order to install the power steering pump pulley.
3. Ensure that the power steering pump pulley (1) is flush against the power steering pump shaft (2) with an allowable variance of 0.25 mm (0.010 in).
4. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-48l-53l-60l-62l-repair-instructions-on-vehicle) .
5. Install the engine coolant fan upper shroud, if equipped. Refer to «Engine Coolant Fan Upper Shroud Replacement (Diesel)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. J-25033-C Pulley Installer
2. J-25034-C Pulley Remover

For equivalent regional tools, refer to Special Tools .

1. Remove the engine coolant fan upper shroud, if equipped. Refer to «Engine Coolant Fan Upper Shroud Replacement (Diesel)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the accessory drive belt. Refer «Drive Belt Replacement»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-43l) .
3. Use the J-25034-C remover in order to remove the power steering pump pulley.

1. Place the power steering pump pulley on the end of the power steering pump shaft.
2. Use the J-25033-C installer in order to install the power steering pump pulley.
3. Ensure that the power steering pump pulley (1) is flush against the power steering pump shaft (2) with an allowable variance of 0.25 mm (0.010 in).
4. Install the accessory drive belt. Refer to «Drive Belt Replacement»(/gmc/sierra-2500/2012-2012/remont/mechanical/#engine-mechanical-43l) .
5. Install the engine coolant fan upper shroud, if equipped. Refer to «Engine Coolant Fan Upper Shroud Replacement (Diesel)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(/gmc/sierra-2500/2012-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the power steering pump pulley. Refer to «Power Steering Pump Pulley Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-pump-pulley-replacement-48l) .
2. Remove as much power steering fluid from the power steering fluid reservoir as possible.
3. Disconnect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
4. Remove the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
5. Place drain pans under the vehicle as needed.
6. Disconnect the power steering fluid cooler hose clamp and the power steering fluid cooler hose from the power steering pump assembly.
7. Remove the power steering pump rear bracket nuts.
8. Remove the power steering pump bolts.
9. Remove the power steering pump bracket bolts and nut.
10. Pull the power steering pump bracket forward.
11. Separate the power steering pump assembly from the power steering pump bracket.
12. Remove the power steering gear inlet hose (2) from the power steering pump assembly (1).
13. Remove the power steering pump assembly from the vehicle.
14. Transfer any parts as needed.

1. Position the power steering pump assembly in the vehicle with the power steering pump bracket.
2. Install the power steering gear inlet hose (2) to the power steering pump assembly (1). Tighten Tighten the fitting to 32 N.m (24 lb ft).
3. Install the power steering pump bracket bolts and nut. Tighten Tighten the bolts and nut to 41 N.m (30 lb ft).
4. Install the power steering pump bolts. Tighten Tighten the bolts to 50 N.m (37 lb ft).
5. Install the power steering pump rear bracket nuts. Tighten Tighten the nuts to 41 N.m (30 lb ft).
6. Connect the power steering fluid cooler hose and the power steering fluid cooler hose clamp to the power steering pump assembly.
7. Clean any excess power steering fluid from the vehicle and remove the drain pans.
8. Connect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
9. Install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
10. Install the power steering pump pulley. Refer to «Power Steering Pump Pulley Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-pump-pulley-replacement-48l) .
11. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
12. Program the power steering control module. Refer to «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .

1. Remove the power steering pump pulley. Refer to «Power Steering Pump Pulley Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-pump-pulley-replacement-48l) .
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the reservoir as possible.
4. Disconnect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
5. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
6. Remove the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. From underneath the vehicle, disconnect the power steering gear inlet hose (2) from the power steering pump.
8. Loosen the power steering fluid cooler hose clamp (5) and disconnect the power steering fluid cooler hose (4) from the power steering pump (1).
9. If equipped with hydroboost, loosen the power brake booster outlet hose clamp (3) and disconnect the power brake booster outlet hose (2) from power steering pump.
10. Remove the power steering pump bracket bolt from the side of the engine.
11. Remove the power steering pump bolts.
12. Remove the power steering pump and the reservoir as an assembly from the vehicle.
13. Transfer any parts as necessary. Refer to «Power Steering Fluid Reservoir Replacement - Off Vehicle (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Fluid Reservoir Replacement - Off Vehicle (4.3L, 4.8L, 5.3L, and 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Fluid Reservoir Replacement - Off Vehicle (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Install the power steering pump and the reservoir as an assembly to the vehicle.
2. Install the power steering pump bracket bolt to the side of the engine and tighten to 50 N.m (37 lb ft).
3. Install the power steering pump bolts and tighten to 50 N.m (37 lb ft).
4. Connect the power steering fluid cooler hose (4) and the power steering fluid cooler hose clamp (5) to the power steering pump (1).
5. If equipped with hydroboost, connect the power brake booster outlet hose (2) and the power brake booster outlet hose clamp (3) to the power steering pump.
6. Connect the power steering gear inlet hose (2) to the power steering pump (1). Tighten the fitting to 33 N.m (24 lb ft).
7. Connect the steering shaft coupling. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
8. Install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
9. Install the power steering pump pulley. Refer to «Power Steering Pump Pulley Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__power-steering-pump-pulley-replacement-48l) .
10. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
11. Clean any excess fluid power steering fluid from the vehicle.
12. Remove the drain pans.
13. Lower the vehicle.

Scheme 10

Power Steering Pump Replacement (L96)

Scheme 11

Power Steering Pump Replacement (6.6L)

Scheme 12

Power Steering Pump Fitting and Seal Replacement (6.6L)

Scheme 13

Power Steering Pump Fitting and Seal Replacement (L96)

Disassembly Procedure

1. Remove the power steering pump assembly from the vehicle. Refer to «Power Steering Pump Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (4.8L, 5.3L, and 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Remove the power steering fluid reservoir studs (2) from the power steering pump assembly (1).
3. Remove the power steering pump fitting (4).
4. Remove the power steering pump fitting seal (3).
5. Remove the power steering pump flow control valve (2) and the power steering pump flow control valve spring (3) from the power steering pump assembly (1).
6. Separate the power steering fluid reservoir (1) and the power steering pump (2).
7. Remove the power steering pump seals (1, 4, 5).
8. Remove and clean the power steering fluid reservoir magnet (3).
9. Inspect the welch plug in the power steering pump (2). DO NOT REMOVE IT. If the welch plug is deformed or dislodged then replace the power steering pump (2).

Assembly Procedure

1. Clean and install the power steering fluid reservoir magnet (3).
2. Install the power steering pump seals (1, 4, 5) to the power steering pump (2).
3. Connect the power steering fluid reservoir (1) and the power steering pump (2).
4. Install the power steering pump flow control valve spring (3) and the power steering pump flow control valve (2) to the power steering pump assembly (1).
5. Install the power steering pump fitting seal (3) to the power steering pump assembly (1).
6. Install the power steering pump fitting (4) to the power steering pump assembly (1). Tighten the fitting to 75 N.m (55 lb ft).
7. Install the power steering fluid reservoir studs (2) to the power steering pump assembly (1). Tighten the studs to 58 N.m (44 lb ft).
8. Install the power steering pump assembly to the vehicle. Refer to «Power Steering Pump Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (4.8L, 5.3L, and 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Scheme 14

Power Steering Fluid Reservoir Replacement - Off Vehicle (L96)

Scheme 15

Power Steering Fluid Reservoir Replacement - Off Vehicle (6.6L)

Scheme 16

Power Steering Pump Flow Control Valve Replacement - Off Vehicle (4.3L, 4.8L, 5.3L, and 6.2L)

1. Remove the power steering pump from the vehicle. Refer to «Power Steering Pump Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (4.8L, 5.3L, and 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Use a chisel in order to cut and remove the power steering pump shaft seal.

1. Lubricate the new power steering pump shaft seal with power steering fluid.
2. Use a deep 1 inch tall socket in order to install the new power steering pump shaft seal.
3. Install the power steering pump. Refer to «Power Steering Pump Replacement (4.3L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Power Steering Pump Replacement (4.8L, 5.3L, and 6.2L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Scheme 17

Steering Gear Pitman Shaft Seal Replacement

Scheme 18

Steering Linkage Outer Tie Rod Replacement

1. Remove the steering linkage outer tie rod. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Remove the steering linkage inner tie rod nut from the steering linkage inner tie rod.
3. Remove the outer boot clamp (2) from the steering gear boot (3).
4. Remove the inner boot clamp from the steering gear boot.
5. Remove the steering gear boot from the steering gear (5).

1. Position the inner boot clamp onto the steering gear boot (3).
2. Apply grease to the steering linkage inner tie rod (1) and to the steering gear (5).
3. Install the steering gear boot onto the steering linkage inner tie rod.
4. Ensure the steering gear boot is not twisted, puckered, or improperly folded.
5. Install the steering gear boot onto the steering gear. Seat the steering gear boot in the groove on the steering gear housing (4).
6. Install the inner boot clamp to the steering gear boot.
7. Install the outer boot clamp (2) to the steering gear boot.
8. Install the steering linkage inner tie rod nut to the steering linkage inner tie rod.
9. Install the steering linkage outer tie rod. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Steering Gear Boot Replacement (Without HP2)

Special Tools

J-22610 Keystone Clamp Pliers

For equivalent regional tools, refer to Special Tools .

1. Remove the steering linkage outer tie rod. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Remove the steering linkage inner tie rod nut (2) from the steering linkage inner tie rod (1).
3. Remove the outer boot clamp (2) from the steering gear boot (1).
4. Remove the inner boot clamp (1) from the steering gear boot (2) with side cutters.
5. Discard the inner boot clamp.
6. Remove the steering gear boot from the steering gear.

1. Position the NEW inner boot clamp (1) onto the steering gear boot (2).
2. Apply grease to the steering linkage inner tie rod (2) and to the steering gear (1).
3. Install the steering gear boot (3) onto the steering linkage inner tie rod.
4. Ensure the steering gear boot is not twisted, puckered, or improperly folded.
5. Install the steering gear boot onto the steering gear. Seat the steering gear boot in the groove on the steering gear housing.
6. Install the inner boot clamp (1) to the steering gear boot (2) with the J-22610 pliers.
7. Install the outer boot clamp (2) to the steering gear boot (1).
8. Install the steering linkage inner tie rod nut (2) to the steering linkage inner tie rod (1).
9. Install the steering linkage outer tie rod. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Remove the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
2. Remove as much power steering fluid from the power steering fluid reservoir as possible.
3. Place drain pans under the vehicle as needed.
4. Disconnect the power steering fluid cooler hose (3) from the steering gear (2).
5. Disconnect the power steering fluid cooler hose (4) from the power steering pump (1).
6. Remove the power steering fluid cooler bolts (2).
7. Remove the power steering fluid cooler (1) from the vehicle.

1. Install the power steering fluid cooler (1) to the vehicle.
2. Install the power steering fluid cooler bolts (2) and tighten to 9 N.m (80 lb in).
3. Connect the power steering fluid cooler hose (4) to the power steering pump (1).
4. Connect the power steering fluid cooler hose (3) to the steering gear (2).
5. Clean any excess fluid from the vehicle and remove the drain pans.
6. Install the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
7. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Remove the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the reservoir as possible.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Remove the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Disconnect the power steering fluid cooler hose (1) from the steering gear (3).
7. Disconnect the power steering fluid cooler hose from the power steering pump (2).
8. Remove the power steering fluid cooler bolts (2).
9. Remove the power steering fluid cooler (1) from the vehicle.

1. Position the power steering fluid cooler (1) in the vehicle.
2. Install the power steering fluid cooler bolts (2) and tighten to 9 N.m (80 lb in).
3. Connect the power steering fluid cooler hose (1) to the power steering pump (2).
4. Connect the power steering fluid cooler hose to the steering gear (3).
5. Install the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Lower the vehicle.
7. Install the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
8. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
9. Clean any excess fluid from the vehicle.
10. Remove the drain pans.

1. Remove the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the reservoir as possible.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Remove the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Disconnect the power steering fluid cooler hose (1) from the steering gear (3).
7. Disconnect the power steering fluid cooler hose from the power steering pump (2).
8. Remove the power steering fluid cooler bolts (2).
9. Remove the power steering fluid cooler (1) from the vehicle.

1. Position the power steering fluid cooler (1) in the vehicle.
2. Install the power steering fluid cooler bolts (2) and tighten to 9 N.m (80 lb in).
3. Connect the power steering fluid cooler hose (1) to the power steering pump (2).
4. Connect the power steering fluid cooler hose to the steering gear (3).
5. Install the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Lower the vehicle.
7. Install the radiator grille. Refer to «Radiator Grille Replacement (GMC)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (Chevrolet HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) , «Radiator Grille Replacement (GMC HD)»(/gmc/sierra-2500/2012-2012/remont/exteriorinterior-trim/#exterior-trim) .
8. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
9. Clean any excess fluid from the vehicle.
10. Remove the drain pans.

Scheme 19

Power Steering Gear Inlet Pipe/Hose Replacement (Gas Without Hydroboost)

Scheme 20

Power Steering Gear Inlet Pipe/Hose Replacement (L96)

Scheme 21

Power Steering Gear Inlet Pipe/Hose Replacement (6.6L)

1. Place drain pans under the vehicle as needed.
2. Disconnect the power steering fluid cooler hose clamp and hose (3) from the steering gear (2).
3. Remove the power steering gear outlet pipe (1) from the steering gear (2).

1. Install the power steering gear outlet pipe (1) to the steering gear (2).
2. Connect the power steering fluid cooler hose (3) and hose clamp to the steering gear (2).
3. Clean any excess fluid from the vehicle and remove the drain pans.
4. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Scheme 22

Power Steering Gear Outlet Pipe/Hose Replacement (Gas Without Hydroboost)

Scheme 23

Electronic Power Steering Motor Control Module Replacement

Steering Gear Replacement (HP2)

Special Tools

J-42640 Steering Column Anti-Rotation Pin

For equivalent regional tools, refer to Special Tools .

1. With the front wheels of the vehicle in the straight ahead position, use the J-42640 Pin in order to lock the steering column.
2. Perform the high voltage disabling procedure. Refer to «High Voltage Disabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) .
3. Remove the front tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/gmc/sierra-2500/2012-2012/remont/wheel-tire-system/#tires-and-wheels) .
4. Disconnect the power steering assist motor electrical connector. Refer to «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
5. Disconnect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
6. Disconnect the steering linkage outer tie rods from the steering knuckles. Refer to «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
7. Support the steering gear with jack stands.
8. Remove the steering gear bolts (1) from the left side of the steering gear.
9. Remove the steering gear bolts (1) from the right side of the steering gear.
10. Remove the steering gear from the vehicle.
11. Transfer any parts as necessary.

1. Position the steering gear in the vehicle.
2. Support the steering gear with jack stands.
3. Install the steering gear bolts (1) at the right side of the steering gear.
4. Tighten the right side steering gear bolts to 100 N.m (74 lb ft).
5. Install the steering gear bolts (1) to the left side of the steering gear.
6. Tighten the left side steering gear bolts to 220 N.m (162 lb ft).
7. Remove the jack stands.
8. Connect the steering linkage outer tie rods to the steering knuckles. «Steering Linkage Outer Tie Rod Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
9. Connect the steering shaft coupling to the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
10. Connect the power steering assist motor electrical connector. Refer to «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
11. Install the front tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/gmc/sierra-2500/2012-2012/remont/wheel-tire-system/#tires-and-wheels) .
12. Remove the J-42640 Pin from the steering column.
13. Perform the high voltage enabling procedure. Refer to «High Voltage Enabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-enabling) .
14. Perform the power steering control module setup procedure. Refer to «Power Steering Control Module Programming and Setup»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems) .
15. Measure and adjust the front toe. Refer to «Wheel Alignment - Steering Wheel Angle and/or Front Toe Adjustment»(/gmc/sierra-2500/2012-2012/remont/wheel-alignment/#wheel-alignment-system__wheel-alignment-steering-wheel-angle) .

Scheme 24

Steering Gear Replacement (Hydraulic Rack and Pinion)

Steering Gear Replacement (L96)

Special Tools

1. CH-49824 Steering Linkage Separator
2. J-24319-B Steering Linkage and Tie Rod Puller
3. J-24420-C Crankshaft Balancer Puller
4. J-42640 Steering Column Anti-rotation Pin

For equivalent regional tools, refer to Special Tools .

1. With the front wheels of the vehicle in the straight ahead position, use the J-42640 pin in order to lock the steering column.
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the reservoir as possible.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Remove the engine shield, if equipped. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Remove the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. Remove the front stabilizer shaft. Refer to «Stabilizer Shaft Replacement (1500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) , «Stabilizer Shaft Replacement (2500, 3500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) .
8. Disconnect the steering hoses from the steering gear.
9. Disconnect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
10. Remove the pitman arm nut (1). Discard the pitman arm nut.
11. Remove the steering linkage relay rod bushing, if equipped.
12. If the vehicle is equipped with a crew cab with single rear wheels (SRW) or any body style with dual rear wheels, use the J-24319-B puller in order to disconnect the pitman arm from the relay rod. If the vehicle is NOT equipped with a crew cab with SRW or any body style with dual rear wheels, use the CH-49824 separator and the J-24420-C puller in order to disconnect the pitman arm from the relay rod.
13. Remove the steering gear bolts (1).
14. Remove the steering gear from the vehicle.
15. Transfer the pitman arm, if necessary. Refer to «Pitman Arm Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-linkage/#steering-linkage-system__pitman-arm-replacement) .

1. If you removed the pitman arm, install the pitman arm. Refer to «Pitman Arm Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-linkage/#steering-linkage-system__pitman-arm-replacement) .
2. Position the steering gear in the vehicle.
3. Install the steering gear bolts (1).
4. Tighten the steering gear bolts to 275 N.m (203 lb ft).
5. Connect the pitman arm to the relay rod.
6. Install the steering linkage relay rod bushing, if equipped.
7. Install the NEW pitman arm nut (1) and tighten to 125 N.m (92 lb ft).
8. Connect the power steering hoses to the steering gear. Tighten the hose fittings to 33 N.m (24 lb ft).
9. Connect the steering shaft coupling to the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
10. Install the front stabilizer shaft. Refer to «Stabilizer Shaft Replacement (1500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) , «Stabilizer Shaft Replacement (2500, 3500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) .
11. Install the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
12. If you removed the engine shield, install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
13. Lower the vehicle.
14. Remove the J-42640 pin from the steering column.
15. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
16. Clean any excess fluid from the vehicle.
17. Remove the drain pans.

1. CH-49824 Steering Linkage Separator
2. J-24319-B Steering Linkage and Tie Rod Puller
3. J-24420-C Crankshaft Balancer Puller
4. J-42640 Steering Column Anti-rotation Pin

For equivalent regional tools, refer to Special Tools .

1. With the front wheels of the vehicle in the straight ahead position, use the J-42640 pin in order to lock the steering column.
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the reservoir as possible.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Remove the engine shield, if equipped. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Remove the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. Remove the charge air cooler inlet pipe. Refer to «Charge Air Cooler Inlet Pipe Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-66l-lgh-lml-repair-instructions) .
8. Remove the front stabilizer shaft. Refer to «Stabilizer Shaft Replacement (1500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) , «Stabilizer Shaft Replacement (2500, 3500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) .
9. Disconnect the steering hoses from the steering gear.
10. Disconnect the steering shaft coupling from the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
11. Remove the pitman arm nut (1). Discard the pitman arm nut.
12. Remove the steering linkage relay rod bushing, if equipped.
13. If the vehicle is equipped with a crew cab with single rear wheels (SRW) or any body style with dual rear wheels, use the J-24319-B puller in order to disconnect the pitman arm from the relay rod. If the vehicle is NOT equipped with a crew cab with SRW or any body style with dual rear wheels, use the CH-49824 separator and the J-24420-C puller in order to disconnect the pitman arm from the relay rod.
14. Remove the steering gear bolts (1).
15. Remove the steering gear from the vehicle.
16. Transfer the pitman arm, if necessary. Refer to «Pitman Arm Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-linkage/#steering-linkage-system__pitman-arm-replacement) .

1. If you removed the pitman arm, install the pitman arm. Refer to «Pitman Arm Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-linkage/#steering-linkage-system__pitman-arm-replacement) .
2. Position the steering gear in the vehicle.
3. Install the steering gear bolts (1).
4. Tighten the steering gear bolts to 275 N.m (203 lb ft).
5. Connect the pitman arm to the relay rod.
6. Install the steering linkage relay rod bushing, if equipped.
7. Install the NEW pitman arm nut (1) and tighten to 125 N.m (92 lb ft).
8. Connect the power steering hoses to the steering gear. Tighten the hose fittings to 33 N.m (24 lb ft).
9. Connect the steering shaft coupling to the steering gear. Refer to «Steering Shaft Coupling Replacement»(/gmc/sierra-2500/2012-2012/remont/steering-column-switches/#steering-wheel-and-steering-column__steering-shaft-coupling-replacement) .
10. Install the front stabilizer shaft. Refer to «Stabilizer Shaft Replacement (1500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) , «Stabilizer Shaft Replacement (2500, 3500)»(/gmc/sierra-2500/2012-2012/remont/suspension-front/#front-suspension-system) .
11. Install the charge air cooler inlet pipe. Refer to «Charge Air Cooler Inlet Pipe Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-66l-lgh-lml-repair-instructions) .
12. Install the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
13. If you removed the engine shield, install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
14. Lower the vehicle.
15. Remove the J-42640 pin from the steering column.
16. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
17. Clean any excess fluid from the vehicle.
18. Remove the drain pans.

Steering Linkage Inner Tie Rod Replacement (HP2)

Special Tools

CH-49009 Inner Tie Rod Wrench

1. Remove the steering gear boot. Refer to «Steering Gear Boot Replacement (Without HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-boot-replacement-without-hp2) , «Steering Gear Boot Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Disengage the steering linkage inner tie rod washer (1) from the steering linkage inner tie rod.
3. Rotate the steering linkage inner tie rod (2) counterclockwise while holding the steering gear rack stationary until the steering linkage inner tie rod separates from the steering gear rack (1).
4. Discard the steering linkage inner tie rod washer.

1. Install the new steering linkage inner tie rod washer on the steering gear rack.
2. Apply LOCTITE® 262 or equivalent to the steering linkage inner tie rod threads.
3. Attach the steering linkage inner tie rod to the steering gear rack and hand tighten it.
4. Tighten the steering linkage inner tie rod using wrench CH-49009 inner tie rod wrench. Tighten Tighten the steering linkage inner tie rod to 145 (107 lb ft).
5. Align the new steering linkage inner tie rod washer (1) to the flats on the steering linkage inner tie rod and bend the tabs over the flats.
6. Install the steering gear boot. Refer to «Steering Gear Boot Replacement (Without HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-boot-replacement-without-hp2) , «Steering Gear Boot Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Remove the steering gear boot. Refer to «Steering Gear Boot Replacement (Without HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-boot-replacement-without-hp2) , «Steering Gear Boot Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Place a pipe wrench on the steering gear rack (1) next to the steering linkage inner tie rod housing (2).
3. Place a wrench on the flats of the steering linkage inner tie rod housing (2).
4. Rotate the steering linkage inner tie rod housing (2) counterclockwise, while holding the steering gear rack stationary, until the steering linkage inner tie rod separates from the steering gear rack (1).

1. Apply LOCTITE® 262, or equivalent, to the steering gear inner tie rod threads.
2. Attach the steering linkage inner tie rod onto the steering gear rack.
3. Place a pipe wrench on the steering gear rack (1) next to the steering linkage inner tie rod housing (2).
4. Tighten the steering linkage inner tie rod housing (2). Tighten Tighten the steering linkage inner tie rod to 150 N.m (111 lb ft).
5. Install the steering gear boot. Refer to «Steering Gear Boot Replacement (Without HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-boot-replacement-without-hp2) , «Steering Gear Boot Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Remove the steering gear. Refer to «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Remove the power steering gear inlet hose retaining plate bolt (1) and the power steering gear inlet hose retaining plate (2).
3. Loosen both steering gear cylinder pipe fittings (3) on the steering gear (4).
4. Remove both steering gear cylinder pipes (2) from the steering gear (4).
5. Remove and discard the steering gear cylinder pipe seals (1) from the steering gear (4).

1. Inspect the steering gear cylinder pipes for the following items: Cracks Dents Damage to the threads
2. Replace the steering gear cylinder pipes as needed.
3. Lubricate and install the new steering gear cylinder pipe seal (1) onto the shorter steering gear cylinder pipe.
4. Place the non-threaded steering gear cylinder pipe end (2) into the steering gear.
5. Place the threaded end of the steering gear cylinder pipe (3) onto the steering gear fitting (4). Start the steering gear cylinder pipe fitting (3) but do not tighten it entirely.
6. Lubricate and install the new steering gear cylinder pipe seal (1) onto the longer steering gear cylinder pipe.
7. Place the non-threaded steering gear cylinder pipe end (2) into the steering gear.
8. Place the threaded end of the steering gear cylinder pipe (3) onto the steering gear fitting (4). Start the steering gear cylinder pipe fitting (3) but do not tighten it entirely.
9. Install the power steering gear inlet hose retaining plate (2) and the power steering gear inlet hose retaining plate bolt (1). Tighten Tighten the bolt to 12 N.m (106 lb in).
10. Tighten the steering gear cylinder pipe fittings. Tighten Tighten the fittings to 34 N.m (25 lb ft).

Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle

1. Remove the steering gear. Refer to «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Loosen the steering gear pitman shaft lash adjuster nut (4).
3. Turn the steering gear pitman shaft lash adjuster screw (1) counterclockwise until fully extended.
4. Turn the steering gear pitman shaft lash adjuster screw clockwise 1 full turn.
5. Rotate the steering gear stub shaft (3) from stop to stop, using a 12-point socket while counting the number of turns.
6. Starting at either stop, turn the steering gear stub shaft (3) back half the total number of turns you counted previously. This is the center position.
7. Ensure the steering gear pitman shaft is centered by inspecting the following items: The flat on the steering gear stub shaft (2) faces upward. The flat on the steering gear stub shaft is parallel with the steering gear side cover. The master spline (3) on the steering gear pitman shaft is in line with the steering gear pitman shaft lash adjuster screw (1).
8. Place a torque wrench on the stub shaft with the handle in the vertical position.
9. Rotate the steering gear stub shaft 45 degrees from each side of the center of the steering gear stub shaft. The steering gear stub shaft must rotate smoothly and must not stick or bind.
10. Record the steering gear worm bearing preload measurement on or near the center.
11. The steering gear worm bearing preload must be 0.8-1.7 N.m (7.1-15.1 lb in), with the steering gear pitman shaft lash adjuster nut installed. If the torque is outside this range, readjust or repair the steering gear assembly.
12. In order to increase the over center preload torque, turn the steering gear pitman shaft lash adjuster screw clockwise. Add torque in increments of 0.7-1.1 N.m (6-10 lb in).
13. Tighten the steering gear pitman shaft lash adjuster nut to 88 N.m (65 lb ft).
14. Install the steering gear. Refer to «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Remove the steering gear. Refer to «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Remove the pitman arm nut (3).
3. Remove the pitman arm washer (2).
4. Clean the exposed end of the pitman shaft.
5. Clean the steering gear housing (1).
6. Use a wire brush in order to clean the steering gear pitman shaft splines.
7. Use the following procedure in order to center the steering gear stub shaft: Rotate the steering gear stub shaft (1) with a wrench from stop to stop. Count the number of turns. Rotate the steering gear stub shaft back 1/2 of the total amount of turns.
8. Remove the steering gear pitman shaft housing cover bolts (1). Remove the steering gear pitman shaft lash adjuster nut (2).
9. Remove the steering gear pitman shaft housing cover (3).
10. Remove the steering gear pitman shaft housing cover O-ring (4).

1. Install the new steering gear pitman shaft housing cover O-ring (4).
2. Install the steering gear pitman shaft housing cover (3).
3. Install the steering gear pitman shaft lash adjuster nut (2).
4. Install the steering gear pitman shaft housing cover bolts (1) and tighten to 57 N.m (42 lb ft).
5. Install the pitman arm washer (2).
6. Install the pitman arm nut (3) and tighten to 370 N.m (273 lb ft).
7. If necessary adjust the steering gear pitman shaft over-center preload. Refer to «Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-pitman-shaft-over-center-preload) .
8. Install the steering gear. Refer to «Steering Gear Replacement (Hydraulic Rack and Pinion)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) , «Steering Gear Replacement (HP2)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-hp2) , «Steering Gear Replacement (L96)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system__steering-gear-replacement-l96) , «Steering Gear Replacement (6.6L)»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Scheme 25

Stub Shaft Housing Replacement

1. Remove the power steering assist motor. Refer to «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
2. Mark the position and directional orientation of every fastener on the two harnesses before separating them.
3. Separate the power steering wiring harness extension harness from the power steering assist motor wiring harness.

1. When replacing either harness, lay the replacement harness side by side with the old harness and transfer every alignment mark.
2. After all alignment marks have been transferred, replace every fastener, installing each one in the correct position with the correct directional orientation.
3. If the alignment marks are lost or not made before separating the harnesses then the following procedure will need to be followed. Otherwise proceed to Step 11.
4. Measure Distance A on the power steering wiring harness extension harness from the top of the electrical connector and make a mark. Distance A is 11 cm (4.33 in).
5. Measure Distance B on the power steering assist motor wiring harness from the top of the electrical connector and make a mark. Distance B is 12.5 cm (5 in).
6. Align the two harnesses by the marks and install the appropriate fastener.
7. Measure Distance A on the power steering wiring harness extension harness from the previously installed fastener and make a mark. Distance A is 20.5 cm (8 in).
8. Pull any slack out of the two harnesses, hold them together at the mark that was made, and install the appropriate fastener.
9. Measure Distance A on the power steering wiring harness extension harness from the previously installed fastener and make a mark. Distance A is 20.5 cm (8 in).
10. Pull any slack out of the two harnesses, hold them together at the mark that was made, and install the appropriate fastener.
11. Install the power steering assist motor. Refer to «Power Steering Assist Motor Replacement»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Perform the high voltage disabling procedure. Refer to «High Voltage Disabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) .
2. Remove the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-hybrid-hp2-60l-lz1-repair-instructions) .
3. Release the power steering assist motor electrical harness connector position assurance tab (3). The connector in the graphic is shown upside down for clarity.
4. Press down on the connector cam lever lock tab (2).
5. Push the connector cam lever (3) toward the rear of vehicle.
6. Separate the power steering assist motor electrical harness retainers from the electronic power steering control module bracket and disengage the electrical connectors (1).
7. Remove the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
8. Remove the steering linkage shield bolts (1) and the steering linkage shield (2).
9. Separate the power steering assist motor electrical harness retainers from the frame of the vehicle.
10. Pull the power steering assist motor electrical harness through the engine compartment to the bottom of the vehicle.
11. Disconnect the power steering assist motor electrical connector at the torque sensor.
12. Remove the power steering assist motor bolts (1).
13. Remove the power steering assist motor and electrical harness (2).
14. Remove and ensure the power steering assist motor seal (3) is kept protected while out of the vehicle as it will be needed for reinstallation.

1. Install any new wiring harness retainers as needed.
2. Position the power steering assist motor (2) and seal (3) to the steering gear.
3. Install the power steering assist motor bolts (1). Tighten Tighten the bolts to 13 N.m (115 lb in).
4. Connect the power steering assist motor electrical connector at the torque sensor.
5. Route the power steering assist motor electrical harness back through the engine compartment to its previous position and secure the lower part of the wiring harness to the frame.
6. Install the steering linkage shield (2) and the steering linkage shield bolts (1). Tighten Tighten the bolts to 12 N.m (106 lb in).
7. Engage the power steering assist motor electrical harness connectors (1) to the electronic power steering control module.
8. Ensure the connector cam lever (3) and the connector cam lever lock tab (2) are fully engaged. The connector in the graphic is shown upside down for clarity.
9. Secure the power steering assist motor electrical harness connector position assurance tab (3).
10. Install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
11. Install the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-hybrid-hp2-60l-lz1-repair-instructions) .
12. Perform the high voltage enabling procedure. Refer to «High Voltage Enabling»(/gmc/sierra-2500/2012-2012/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-enabling) .
13. Perform the power steering control module setup procedure. Refer to «Power Steering Control Module Programming and Setup»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems) .

1. Remove the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Place drain pans under the vehicle as needed.
3. Remove as much power steering fluid from the power steering fluid reservoir as possible.
4. Disconnect the power brake booster inlet hose from the power steering pump (3).
5. Disconnect the power brake booster inlet hose (1) from the power brake booster (2).
6. Remove the power brake booster inlet hose (1) from the vehicle.

1. Install the power brake booster inlet hose (1) to the vehicle.
2. Connect the power brake booster inlet hose (1) to the power brake booster (2). Tighten the fitting to 33 N.m (24 lb ft).
3. Connect the power brake booster inlet hose (1) to the power steering pump (3). Tighten the fitting to 33 N.m (24 lb ft).
4. Clean any excess fluid from the vehicle and remove the drain pans.
5. Install the engine shield. Refer to «Engine Shield Replacement»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Place drain pans under the vehicle.
2. Remove as much power steering fluid from the power steering fluid reservoir (1) as possible.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
4. Remove the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
5. Disconnect the power brake booster inlet hose (4) from the power steering pump (2).
6. Disconnect the power brake booster inlet hose from the power brake booster.
7. Remove the power brake booster inlet hose from the vehicle.

1. Position the power brake booster inlet hose in the vehicle.
2. Connect the power brake booster inlet hose to the power brake booster.
3. Connect the power brake booster inlet hose (4) to the power steering pump (2).
4. Tighten the power brake booster inlet hose fittings to 33 N.m (24 lb ft).
5. Install the left front wheelhouse liner. Refer to «Front Wheelhouse Liner Replacement - Left Side (GMC)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) , «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(/gmc/sierra-2500/2012-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Lower the vehicle.
7. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .
8. Clean any excess fluid from the vehicle.
9. Remove the drain pans.

1. Remove the engine control module. Refer to «Engine Control Module Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-66l-lgh-lml-repair-instructions)
2. Place drain pans under the vehicle.
3. Remove as much power steering fluid from the power steering fluid reservoir (1) as possible.
4. Disconnect the power brake booster inlet hose (5) from the hose clip (2).
5. Disconnect the power brake booster inlet hose (5) from the power steering pump (4).
6. Disconnect the power brake booster inlet hose (5) from the power brake booster.
7. Remove the power brake booster inlet (5) hose from the vehicle.

1. Position the power brake booster inlet hose (5) in the vehicle.
2. Connect the power brake booster inlet hose (5) to the power brake booster.
3. Connect the power brake booster inlet hose (5) to the power steering pump (4).
4. Tighten the power brake booster inlet hose fittings to 33 N.m (24 lb ft).
5. Connect the power brake booster inlet hose (5) to the hose clip (2).
6. Clean any excess fluid from the vehicle.
7. Remove the drain pans.
8. Install the engine control module. Refer to «Engine Control Module Replacement»(/gmc/sierra-2500/2012-2012/remont/testing-diagnostics/#engine-controlsfuel-66l-lgh-lml-repair-instructions)
9. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

1. Place drain pans under the vehicle as needed.
2. Remove as much power steering fluid from the power steering fluid reservoir as possible.
3. Disconnect the power brake booster outlet hose (1) from the power brake booster (2).
4. Disconnect the power brake booster outlet hose (1) from the power steering fluid reservoir (3).
5. Remove the power brake booster outlet hose (1) from the vehicle.

1. Install the power brake booster outlet hose (1) to the vehicle.
2. Connect the power brake booster outlet hose (1) to the power steering fluid reservoir (3).
3. Connect the power brake booster outlet hose (1) to the power brake booster (2).
4. Clean any excess fluid from the vehicle and remove the drain pans.
5. Fill and bleed the power steering system. Refer to «Power Steering System Bleeding»(/gmc/sierra-2500/2012-2012/remont/manual-power-steering/#power-steering-system) .

Scheme 26

Power Brake Booster Outlet Hose Replacement (L96)

Scheme 27

Power Brake Booster Outlet Hose Replacement (6.6L)

The hydraulic power steering pump is a constant displacement vane-type pump that provides hydraulic pressure and flow for the power steering gear. The hydraulic power steering pump is belt-driven.

The power steering fluid reservoir holds the power steering fluid and may be integral with the power steering pump or remotely located. The following locations are typical locations for the remote reservoir

1. Mounted to the front of the dash panel
2. Mounted to the inner fender
3. Mounted to a bracket on the engine

The 2 basic types of power steering gears are listed below

1. A recirculating ball system
2. A rack and pinion system

In the recirculating ball system, a worm gear converts steering wheel movement to movement of a sector shaft. A pitman arm attached to the bottom of the sector shaft actually moves one tie rod and an intermediate rod move the other tie rod.

In the rack and pinion system, the rack and the pinion are the 2 components that convert steering wheel rotation to lateral movement. The steering shaft is attached to the pinion in the steering gear. The pinion rotates with the steering wheel. Gear teeth on the pinion mesh with the gear teeth on the rack. The rotating pinion moves the rack from side to side. The lateral action of the rack pushes and pulls the tie rods in order to change the direction of the vehicle's front wheels.

The power steering pressure hose connects the power steering pump union fitting to the power steering gear and allows pressurized power steering fluid to flow from the pump to the gear.

The power steering return hose returns fluid from the power steering gear back to the power steering fluid reservoir. The power steering return line may contain an integral fin-type or line-type power steering fluid cooler.

In a typical power steering system, a pump generates hydraulic pressure, causing fluid to flow, via the pressure hose, to the steering gear valve assembly. The steering gear valve assembly regulates the incoming fluid to the right and left chambers in order to assist in right and left turns.

Turning the steering wheel activates the valve assembly, which applies greater fluid pressure and flow to 1 side of the steering gear piston, and lower pressure and flow to the other side of the piston. The pressure assists the movement of the gear piston. Tie rods transfer this force to the front wheels, which turn the vehicle right or left.

The 42-volt rack & pinion electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle using the power steering control module (PSCM) to control the power steering motor to maneuver the steering gear. The PSCM also uses a combination of the torque sensor, motor rotational sensor, 42-volt circuit, battery voltage circuit and serial data circuit to perform the system functions. The PSCM monitors vehicle speed from the engine control module (ECM) via the serial data circuit to determine the amount of steering assist needed to steer the vehicle. At low speeds more assist is provided for easy turning during parking maneuvers. At higher speeds less assist is provided for improved road feel and directional stability.

The EPS system consists of the following components

1. The PSCM
2. The power steering motor
3. The power steering motor rotational sensor
4. The torque sensor
5. The steering gear (rack and pinion)
6. The accessory power module (APM)

The PSCM and power steering motor are both serviced separately. The power steering motor is serviced separately from the steering gear; however the power steering motor rotational sensor is serviced as part of the steering motor. The torque sensor is integrated with the steering gear pinion and is serviced as part of the steering gear.

Power Steering Control Module

The accessory power module (APM) provides a shielded, 42-volt circuit to the power steering control module (PSCM) to drive the power steering motor. The PSCM also uses the 12-volt battery circuit to power the module electronics. The normal operation voltage range the APM provides to the PSCM is between 40-44 volts. The APM is not capable of handling more than 58 volts. The dynamic brake circuit of the PSCM is used to keep the reverse motor voltage of the electric power steering system below 58 volts, and will start to consume the surplus voltage if the 42-volt circuit rises in a range between 50-58 volts.

The APM is also monitored by the hybrid control module (HCM) to detect overheating. If overheating of the APM is detected, the HCM sends a serial data message to the PSCM via the serial data gateway module as the power output to the PSCM is reduced until the APM returns to a normal operating temperature. The PSCM will reduce power assist according to the reduced output power provided by the APM, and will return to full steering assist when the APM returns to normal operating temperature.

The PSCM uses a combination of commanded motor voltage and current levels to calculate an estimated power steering system temperature. Neither the PSCM nor the power steering motor are designed to handle around 60-amps continuously and will enter into overload protection mode if the system is exposed to exclusive static steering conditions. If the steering wheel is turned to its maximum rotation point and held at this position for an extended period of time, the PSCM will reduce the amount of current commanded to the power steering motor, which reduces the amount of steering assist as well as system temperature. The PSCM has the ability to detect malfunctions within the power steering system. Any malfunction detected will cause the SERVICE POWER STEERING message to be displayed on the driver information center (DIC).

Torque Sensor

The power steering control module (PSCM) uses a combination of the torque sensor, motor rotational sensor, vehicle speed, and calculated system temperature inputs to determine the amount of assist needed. As the steering wheel is turned and torsional twist is applied to the steering shaft, the torque sensors input and output shaft sinusoidal voltage signals are processed by the PSCM to detect and calculate the steering torque. Additionally, the difference between the angle of the steering output and input shafts detected by the torque sensor and the sinusoidal voltage signals of the motor rotational sensor are both processed by the PSCM to detect and calculate the steering wheel angle.

Power Steering Motor

The power steering control module (PSCM) responds to the change in the sinusoidal voltage signals of the torque and motor rotational sensors by commanding current to the power steering motor. The motor is attached to the base of the steering gear housing and assists the steering gear pinion to maneuver the rack from left to right according to turning the steering wheel. The 42-volt circuit from the APM supplies power to the pulse width modulated (PWM) motor drive circuit. The motor is a brushless, 3 phase motor with a rated maximum phase current of 40-amps rms.

Illustration Tool Number/Description CH-49009 Inner Tie Rod Wrench CH-49824 Steering Linkage Puller GE-28431-6 J-28431-6 Fluorescent Oil Dye - 6 1 oz J-4245 Internal Snap Ring Pliers J-8001 Dial Indicator Set J-22610 Keystone Clamp Pliers J-24319-B Steering Linkage and Tie Rod Puller J-24420-C Crankshaft Balancer Puller J-24433 Pinion Cone and Side Bearing Installer J-25033-C Pulley Installer J-25034-C Pulley Remover J-39570 Chassis Ear J-42640 Steering Column Anti-Rotation Pin J-44586 Power Steering Gear Oil Seal Remover/Installer J-44721 Power Steering Analyzer

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See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• High Voltage Disabling
• Diagnostic Trouble Code (DTC) List - Vehicle
• Steering Wheel in the Full Turn Position Caution
• Hydraulic Brake Booster Leak Inspection
• Drive Belt Falls Off and Excessive Wear Diagnosis
• Steering Linkage Inspection
• Drive Belt Replacement - Accessory
• Upper Intermediate Steering Shaft Replacement
• Steering Shaft Coupling Replacement
• Symptoms - Hydraulic Brakes
• Lifting and Jacking the Vehicle
• Tire and Wheel Removal and Installation
• Wheel Alignment Measurement
• Steering Shaft Upper Bearing Replacement
• Steering Column Replacement (HP2)
• Steering Column Replacement (Without HP2)
• Upper Control Arm Replacement (1500)
• Upper Control Arm Replacement (2500, 3500)
• Lower Control Arm Ball Joint Replacement (2500, 3500)
• Fluid and Lubricant Recommendations
• Drive Belt Replacement
• Engine Coolant Fan Upper Shroud Replacement (Diesel)
• Drive Belt Replacement
• Engine Shield Replacement
• Fastener Caution
• Power Steering Hose Disconnected Caution
• Engine Control Module Replacement
• Auxiliary Generator Replacement (KD9)
• Pitman Arm Replacement
• Wheel Alignment - Steering Wheel Angle and/or Front Toe Adjustment
• Radiator Grille Replacement (GMC)
• Drive Motor Generator Control Module Assembly Replacement
• High Voltage Enabling
• Power Steering Control Module Programming and Setup
• Pipe Wrench Positioning Caution
• Air Cleaner Resonator Outlet Duct Replacement
• DTC C0176
• Steering Gear Replacement (HP2)
• Steering Gear Replacement (L96)
• Power Steering Fluid Leaks
• Checking and Adding Power Steering Fluid (Without Hydroboost)
• Poor Return of Steering Wheel
• Steering Effort Hard in One or Both Directions (HP2)
• Steering Effort Too Easy in One or Both Directions
• Power Steering Pump Specifications
• Power Steering Pump Pulley Replacement (4.8L, 5.3L, 6.0L, or 6.2L)
• Steering Linkage Inner Tie Rod Inspection
• Steering Linkage Outer Tie Rod Inspection
• Fastener Tightening Specifications
• Steering Linkage Inner Tie Rod Replacement (HP2)
• Adhesives, Fluids, Lubricants, and Sealers
• Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle
• Steering Gear Boot Replacement (Without HP2)