The Equinox was the first crossover SUV from Chevrolet. Riding on GM’s Theta platform, the Equinox is mechanically similar to the GMC Terrain, Saturn Vue, Pontiac Torrent and the Suzuki XL7.
The alignment process of the Equinox is mechanically straightforward. The front suspension is a MacPherson strut design with hydraulic bushings in the lower control arms. The rear suspension is a four-link layout.
To make a front camber adjustment, you must install cam bolts or elongate the mounting holes in the struts. Caster is not adjustable, but make sure you look at the cross caster angles to determine the condition of the control arm and bushings and frame.
The rear cams can have significant “cross talk,” so always recheck both angles after any adjustment of either cam.
Inspection of the bushings is necessary before you perform the alignment. The front control arms use a rear bushing filled with hydraulic fluid. Chambers pass fluid at different rates depending on the movement of the suspension. When the bushing is working properly, it can be stiff under aggressive driving and gentle while traveling in a straight line.
Typically, hydraulic bushings do not leak; the damage is usually internal. Symptoms of a damaged bushing include rattle noise coming from the front of the vehicle while driving at slow speeds (approximately 5-10 mph) over rough road surfaces. GM has released updated bushings for 2005-2007 models to address the design of earlier bushings (Bulletin No.: 07-03-08-004).
The Equinox is equipped with Electric Power Steering (EPS). During an alignment or other suspension service, it is important to remember the steering position sensor need to be re-calibrated afterwards.
The system uses the power steering control module (PSCM), torque sensor, motor rotational sensor, motor, discrete battery voltage supply circuit, and the GMLAN serial data circuit to perform the system functions.
If any adjustments are made to either the front or rear toe angles, it is critical to recalibrate the steering angle sensor. Failing to perform this procedure can damage the power steering module.
The PSCM will go into overload protection mode to avoid system thermal damage if the steering wheel is held in a off center position for an extended period of time. The PSCM will limit the amount of current commanded to the EPS motor, which will reduce the power steering assist level. If the PSCM detects a high system temperature and the overload protection mode is initiated, DTC C0176 System Thermal Error may set.
The steering angle sensor centering procedure can be preformed with a scan tool or and any additional sensors associated with this process as required by the vehicle manufacturer. Hunter’s CodeLink tool, which is programmed to address GM’s requirements relative to recalibrating the steering position sensor. Hunter has simplified the process with a seamless transition from the final front toe adjustment to the required reset of the components associated with the EPS system.
The scan tool will guide you through the following procedure:
1. Using the steering wheel, align the front wheels forward.
2. Set the transmission in the PARK position.
3. Install the scan tool into the OBD II connector.
4. Turn the ignition switch ON, with the engine OFF.
5. Select Chassis/EBCM control system Vehicle Stability Enhancement System (VSES), special function test, and Steering Position Sensor Calibration.
6. Follow the scan tool directions to complete the automated centering procedure. This should include turning the steering wheel left 5º and right 5º and then straight forward.
7. Clear any DTCs that may be set. Perform the Diagnostic System Check to verify no current DTCs.
8. Test drive the vehicle.
The strut front suspension is bolted to the knuckle by two bolts that make it possible to use the EZCam XR for alignment. This part is designed to adjust camber by up to plus or minus 1.5° without any modification to the strut or knuckle. It is used on many strut suspensions systems of similar design and is a commonly used part. Ease of installation and adjustment make the EZCam a good alignment option. The Specialty Products part number 81260 is used on this front suspension.
The rear suspension consists of an independent multi-link that has a special cam nut used for rear toe and/or camber adjustment. Sometimes there is no cam nut installed on one of the two parallel arms. The frame brackets on both of these control arms are slotted and have shoulders stamped in the frame to accept this special cam nut. Adjusting either of these arms without using the special cam nut is very difficult.
As soon as you loosen the bolt, the arm will slam one direction or the other because of the vehicle weight. The vehicle can be lifted by the frame to make adjustment easier, but now the bushing is not in the loaded position when the bolt is tightened. This, as everyone knows, is a big no-no. Installing another cam nut, such as the Specialty Products part number 87420, will make adjusting the rear camber and/or toe on these vehicles much easier. Just remove the existing nut and install the cam nut so it is located between the frame bracket shoulders. Adjustment range for these vehicles is approximately 2 degrees. Dial in the necessary adjustments and tighten the head of the bolt making sure the bolt is not cocked or binding in the frame bracket.
Technical Trainer/Designer II
Specialty Products Company