AfterMarketNews AfterMarketNews Auto Care Pro AutoCareCareerHub Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service Speedville

Strange Requests At The Service Counter

Sometimes, I have to wonder if certain ­customers’ brains are firing on all cylinders. But as an automotive service professional, I have to maintain a certain level of self-control while answering their questions, even though what they’re...

Read more...

Are All Cars ‘Supercars’ Now?

I attended an open house at Smokey’s Dyno in Akron, Ohio, last month. The shop was filled with Lamborghinis, Jaguars and other high-end cars. It was a great chance to look under the hoods of some supercars. The shop even had a rare McLaren P1 sitting...

Read more...

Documenting Inspections: Are You Leaving Maintenance Dollars on the Table?

How do you translate scribbles on a ­repair order into sales? There is no magic trick involved — the key is to document the vehicle ­inspection process. The more you know about your customers’ vehicles, and the more you are able to document...

Read more...

Mazda: Performing Regular Undercar Maintenance

This month, we’ll take a look at brake and undercar service on the Mazda vehicle lineup, with the footnote that even though this type of work ­becomes routine when you have a preventive maintenance mindset, good work habits from beginning to end are...

Read more...

Import Automatic Transmission Diagnostics

Don’t be alarmed if you pull an automatic transmission trouble code when diagnosing a “check engine” warning light! Since the automatic transmission operation has a major effect on grams-per-mile exhaust emissions, you’re going to see the...

Read more...

Honda: Vehicle Won’t Move or Barely Moves

A customer brings in a vehicle that won’t move forward, ­­backward or both. Check first to see if it grinds or clicks. And does the speedometer read a lot higher than you’re actually going? Chances are the driveshaft is disengaged. This can...

Read more...

iATN Exceeds 2 Million Forum Messages

The number of messages in the professional automotive discussion forums of the International Automotive Technicians Network (iATN) exceeded 2 million in early December 2014, with the Shop Management and Technical Discussion forums being the most popular...

Read more...

Diagnosing Starter Misses

Contributing writer Gary Goms was called to a friend’s shop to help with a no-cranking condition on a 2006 Chevy Tahoe. After diagnosing a faulty PCM ground, locating the missing ground proved to be problematic. Find out how Gary solves The Case...

Read more...

Snap-on Adds Diagnostic Calculator To Website

Snap-on announces a new diagnostic calculator feature has been added to its website at http://diagnostics.snapon.com to help automotive repair technicians and shop owners determine how much profit they could be making by using a Snap-on diagnostic platform,...

Read more...

Head Gasket Do’s and Don’ts

DO: Clean the holes. To ensure accurate torque values and to avoid cracking the cylinder block, clean any dust, dirt, oil and fluid from the cylinder block head bolt holes before installing the new head gasket and head bolts. Never lubricate the...

Read more...

Harmonic Dampeners: Why They Fail, What to Look For

Every time a cylinder fires, the crankshaft speeds up a very small amount for a short period of time. It is then slowed down as the next cylinder in the firing order compresses air and fuel for the next combustion event. The speeding up and slowing...

Read more...

Be Careful When Replacing That Diesel Air Filter

Modern passenger and light-duty diesels with ECMs have mass airflow sensors and precisely control fuel ­delivery. Key to the efficiency and lifespan of the diesel engine is the diesel air filter. A restricted air filter will not affect fuel economy but...

Read more...

Home Alignment Spec Alignment & Suspension Specs: 2005-2010 Chevy Cobalt and Pontiac G5

Print Print Email Email

If you were to look at the underside of a 2005-2010 Chevy Cobalt or Pontiac G5, the recipe doesn’t look that much different that a 1995-2004 Chevrolet Cavalier or Pontiac Sunfire. The basic ingredients of a strut front suspension and loaded beam axle rear suspension are still there. But, GM introduced several new ingredients that can change how this vehicle is aligned.

Electric Power Steering (EPS)
The greatest difference in the 2005 Chevy Cobalt can’t be seen from under the car. It is the electric power steering (EPS). Knowing the basics of this system can save you problems before the vehicle is pulled into the alignment bay.

EPS eliminates the power steering pump, which can use as much as 8 to 10 horsepower under load. This improves fuel economy while also eliminating the weight and bulk of the power steering pump and hoses. Getting rid of the hydraulics also does away with leaks and the need to check the power steering fluid.

When the driver turns the wheel, a steering sensor detects the position and rate of rotation of the steering wheel. This information, along with input from a steering torque sensor mounted in the steering shaft, is fed to the power steering control module. Other inputs, such as vehicle speed and inputs from the traction control or stability control systems, are factored in to determine how much steering assist is required. The control module then commands the motor to rotate a certain amount, and a sensor on the motor provides feedback to the control module so it can monitor the motor’s position.

If a sensor or other component in the EPS system fails, the self-diagnostics should detect the fault, set a code and disable power-assist. A warning light will illuminate to alert the driver, and the driver will notice a significant increase in steering effort when turning the vehicle.

The Cobalt’s EPS system has four modes of operation. By understanding the four modes, you can make a diagnosis in less time.

• Normal mode: Left and right assist is provided in response to inputs and vehicle speed.

• Return mode: Used to assist steering return after completing a turn. Feedback from the steering position sensor prevents the EPS system from “overshooting” the center position. If the steering position sensor is faulty, it can cause “on center” problems when the toe is set.

• Damper control mode: Used to improve road feel and dampen kickback, this mode typically kicks in at higher vehicle speeds. If the caster angle is too far out of specification, the damper mode can over or under compensate.

• Protection mode: Protects electrical components from thermal damage and excessive current flow if the steering is held all the way to one side in the lock position too long.

The steering wheel position sensor determines the “on center” position. This is used to keep return assist from going over center once a turn is completed. The GM unit is a 5-volt dual analog triangle signal device with a valid signal voltage range of 0 to 5 volts. The sensors’ signal 1 and signal 2 voltage values will increase and decrease within 2.5- to 2.8-volts of each other as the steering wheel is turned. This information can be very useful during diagnosis.

In GM EPS systems, the Power Steering Control Module (PSCM) must be set up with the correct “steering tuning,” which are different in relation to the vehicles powertrain configuration, sedan, coupe, tire and wheel size, etc. This may require a scan tool with flash capabilities.

If you are trying to diagnosis EPS or a suspension making noise, there is a simple trick. GM has a technical service bulletin (07-02-35-004 Feb. 02, 2007) out on a noise problem with EPS steering on the Cobalt, Chevy HHR and Pontiac G5. The bulletin describes a steering column rattle or knocking noise that may be heard or felt at low speeds (5 to 15 mph).

The noise is most noticeable when making a slow turn on a loose or rough surface. The EPS system can be temporarily disabled by removing the 60-amp EPS fuse in the underhood fuse block.

If the rattle persists, it is due to backlash within the steering column (assist motor gear mechanism).
Replace the 60 amp EPS fuse and test drive again. If the steering column is identified as the source of the rattle/knocking noise, the steering column needs to be replaced.

Front Camber Adjustment
If this is not the vehicle’s first alignment, loosen both strut-to-knuckle nuts just enough to allow for movement. The factory recommended procedure is to elongate the lower strut mounting holes. If the strut has not been modified previously, it is more profitable to install aftermarket cam bolts.

Front Caster

The front caster is not adjustable. If the front caster angle is not within specifications, inspect for suspension support misalignment or front suspension damage. Replace any damaged suspension components as necessary. The inboard rear bushing is susceptible to wear and damage that could produce positive caster. It will also make a clunking noise on acceleration and braking.

Front Toe
Ensure that the steering wheel is set in a straight-ahead position. Loosen the tie rod jam nut. Adjust the toe to specification by turning the adjuster. Tighten the tie rod jam nut to 68 Nm (50 ft. lbs.) when the adjustment is completed.

Rear Toe and Camber
The rear suspension is a loaded beam axle. While it is difficult to damage this large part, it can be prone to wear and tear on the bushings, swaybar mounts and spring insulators.

The rear suspension angles can be adjusted with the installation of a shim that is placed between the rear hub and axle mounting plate. A shim should be able to change toe or camber 1 to 1.5 degrees. If a shim is required, make sure that one is not already installed on the vehicle. If one is present, remove the old shim and measure the base line angles.

It has been reported that on some rear disc brake vehicles, the introduction of a shim may cause the caliper to bind or the rotor to strike the caliper bracket.

TPMS Sensor Matching

1. Set the parking brake.

2. Turn the ignition switch to ON/RUN with the engine off.

3. Press and hold the keyless entry fob transmitter’s LOCK and UNLOCK buttons, at the same time, for about five seconds to start the TPMS learn mode. The horn sounds twice indicating the TPMS receiver is ready and in learn mode.

4. Starting with the left front tire, activate the sensor by holding the  TPMS tool aimed upward against the tire sidewall close to the wheel rim at the valve stem location. Press and release the activate button and wait for a horn chirp.

5. Once the horn chirp has sounded, the sensor information is learned and the turn signal in the next location to be learned will illuminate. On most models, the driver-side front turn signal also comes on to indicate that corner’s sensor is ready to be learned. Once the learn mode has been enabled, each of the sensors unique identification codes can be learned.

6. When a sensor ID has been learned, the module sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted its ID and has received and learned it. The module must learn the sensor IDs in the proper sequence to determine sensor’s location. The first learned ID is assigned to the left front location, the second to right front, the third to right rear and the fourth to left rear. On most models, the turn signals will individually illuminate indicating which location is to be learned in the proper sequence.

Relearn Tips
• It is best to perform the TPMS relearn procedure away from the shop in the parking lot.
• Aim at the sidewall below the valve stem, and not at the stem.
• If you cannot get a sensor to initialize, try pushing the vehicle forward a foot or two. The signals can be blocked by components like rotors, calipers and knuckles. By repositioning the sensor, it may unblock the sensor. 

The following two tabs change content below.

Andrew Markel

Andrew Markel is an ASE Certified Technician and former service writer, and he brings this practical knowledge to the Brake & Front End team as editor.
Latest articles from our other sites:

Head Gasket Do’s and Don’ts

DO: Clean the holes. To ensure accurate torque values and to avoid cracking the cylinder block, clean any dust, dirt, oil and fluid from the cylinder block head bolt holes before installing the...More

CARDONE Innovation Team Announces New Products

CARDONE Industries has introduced several new products to its portfolio of automotive replacement parts. Electronic braking units have been added to the company’s remanufactured brakes offering. According...More

Mazda: Performing Regular Undercar Maintenance

This month, we’ll take a look at brake and undercar service on the Mazda vehicle lineup, with the footnote that even though this type of work ­becomes routine when you have a preventive maintenance...More

Import Automatic Transmission Diagnostics

Don’t be alarmed if you pull an automatic transmission trouble code when diagnosing a “check engine” warning light! Since the automatic transmission operation has a major effect on grams-per-mile...More

iATN Exceeds 2 Million Forum Messages

The number of messages in the professional automotive discussion forums of the International Automotive Technicians Network (iATN) exceeded 2 million in early December 2014, with the Shop Management and...More

Loosen Seized Fasteners with Lisle’s Small Fastener Remover

Use Lisle’s Small Fastener Remover (60530) with a pneumatic impact tool to loosen rusted or seized fasteners. A 3/4" open end wrench can be used to turn the socket while impacting the fastener. A...More

Head Gasket Do’s and Don’ts

DO: Clean the holes. To ensure accurate torque values and to avoid cracking the cylinder block, clean any dust, dirt, oil and fluid from the cylinder block head bolt holes before installing the...More

Harmonic Dampeners: Why They Fail, What to Look For

Every time a cylinder fires, the crankshaft speeds up a very small amount for a short period of time. It is then slowed down as the next cylinder in the firing order compresses air and fuel for the next...More