Service advance track warning

[crucianpilot]

So the other day I'm in the car making a right turn at slow speed. All of a sudden, the steering wheel jerks left and locks up and I get a service advance track warning light as well as the traction control lights. Turn the car off and start it back up, all lights go off and steering is normal. A little while later, jump in the car and it happens again except for no warning lights. Took it to the dealer and they say the steering rack needs to be replaced. Pick up the car and everything is normal. This morning, same thing happens again with the warning lights illuminated. Any ideas? Going back to the dealer as soon as I get back in town.

 

[railroad]

I would like to see their diagnostic analysis. My first guess would be sensors, but just guessing.

 

[Snoopy49]

Steering System

Electronic Power Assist Steering (EPAS) System

The EPAS system provides power steering assist to the driver by replacing the conventional hydraulic valve system with an electric motor coupled to the steering gear. The EPAS system includes a steering feel selection function that enables the driver to select a steering feel option that suits their driving requirements. The steering feel selection is made through the vehicles message center.

The 3 steering feel options are:

• Standard
• Sport
• Comfort

Refer to the owners literature, Message Center, Steering Feel, for further information.

The Electronic Power Assist Steering (EPAS) system consists of the following components:

• Power Steering Control Module (PSCM) — The PSCM controls the functions of the EPAS system and communicates with other modules that are on the High Speed Controller Area Network (HS-CAN) bus. The PSCM is attached to the EPAS gear assembly and is not available separately for service.
• Motor — The EPAS gear uses a 12-volt reversible motor to control the steering effort. The motor is connected to the steering rack by a toothed belt and a pulley/bearing assembly. The motor is used by the PSCM to move the rack inside the gear housing. Motor position is used to determine steering wheel angle/position instead of using a separate sensor. The motor is attached to the RH side of the EPAS gear assembly and is not available separately for service.
• EPAS gear assembly — The vehicle has 3 EPAS steering gear options available: 75 mm (2.952 in) travel, 68 mm (2.677 in) travel and a 63 mm (2.48 in) travel option. The steering gear installed to the vehicle is dependant on the wheel and tire configuration the vehicle was built with.
• Steering shaft torque sensor — The steering shaft torque sensor is used by the PSCM to determine how much force is being used to turn the steering wheel. The sensor sends out 2 signals, one for left and one for right. When the steering wheel is turned to the left, the left signal increases while the right signal decreases, likewise when the steering wheel is turned to the right, the right signal increases while the left signal decreases. This allows the PSCM to determine if the driver intends to go left or right in order to spin the motor in the appropriate direction. The sensor is mounted inside the EPAS gear assembly and is not available separately for service.
• Inner tie rod — One inner tie rod is located at each end of the EPAS gear assembly and is available separately for service. There are 3 different inner tie rods available, each matched to one of the steering gear options available for the vehicle. Care must be taken to make sure the correct tie rod for the steering gear installed to the vehicle is used when installing a new inner tie rod. For additional information, refer to Section 211-02 .
• Outer tie rod — One outer tie rod is located at each end of the EPAS gear assembly and is available separately for service. For additional information, refer to Section 211-02 .
• EPAS gear bellows boot — One bellows boot is located on each side of the EPAS gear assembly. Each boot is held in place with 2 boot clamps. The boots and clamps are available for service, refer to Section 211-02 .
• EPAS gear isolator — One rubber isolator is located on the right rear attaching point of the EPAS gear assembly. The isolator aids in the reduction of NVH concerns and is not available separately for service.

The EPAS system utilizes a rack-and-pinion type steering gear. Power assist is provided by a motor that is connected to the steering rack by a belt and a pulley and bearing assembly. The steering gear and motor/module are serviced as an assembly. A new steering gear includes inner tie rods, however, the inner and outer tie rods can also be serviced separately. For additional information on tie rod end service, refer to Section 211-02 .

 

[crucianpilot]

Steering System

Electronic Power Assist Steering (EPAS) System

The EPAS system provides power steering assist to the driver by replacing the conventional hydraulic valve system with an electric motor coupled to the steering gear. The EPAS system includes a steering feel selection function that enables the driver to select a steering feel option that suits their driving requirements. The steering feel selection is made through the vehicles message center.

The 3 steering feel options are:

• Standard
• Sport
• Comfort

Refer to the owners literature, Message Center, Steering Feel, for further information.

The Electronic Power Assist Steering (EPAS) system consists of the following components:

• Power Steering Control Module (PSCM) — The PSCM controls the functions of the EPAS system and communicates with other modules that are on the High Speed Controller Area Network (HS-CAN) bus. The PSCM is attached to the EPAS gear assembly and is not available separately for service.
• Motor — The EPAS gear uses a 12-volt reversible motor to control the steering effort. The motor is connected to the steering rack by a toothed belt and a pulley/bearing assembly. The motor is used by the PSCM to move the rack inside the gear housing. Motor position is used to determine steering wheel angle/position instead of using a separate sensor. The motor is attached to the RH side of the EPAS gear assembly and is not available separately for service.
• EPAS gear assembly — The vehicle has 3 EPAS steering gear options available: 75 mm (2.952 in) travel, 68 mm (2.677 in) travel and a 63 mm (2.48 in) travel option. The steering gear installed to the vehicle is dependant on the wheel and tire configuration the vehicle was built with.
• Steering shaft torque sensor — The steering shaft torque sensor is used by the PSCM to determine how much force is being used to turn the steering wheel. The sensor sends out 2 signals, one for left and one for right. When the steering wheel is turned to the left, the left signal increases while the right signal decreases, likewise when the steering wheel is turned to the right, the right signal increases while the left signal decreases. This allows the PSCM to determine if the driver intends to go left or right in order to spin the motor in the appropriate direction. The sensor is mounted inside the EPAS gear assembly and is not available separately for service.
• Inner tie rod — One inner tie rod is located at each end of the EPAS gear assembly and is available separately for service. There are 3 different inner tie rods available, each matched to one of the steering gear options available for the vehicle. Care must be taken to make sure the correct tie rod for the steering gear installed to the vehicle is used when installing a new inner tie rod. For additional information, refer to Section 211-02 .
• Outer tie rod — One outer tie rod is located at each end of the EPAS gear assembly and is available separately for service. For additional information, refer to Section 211-02 .
• EPAS gear bellows boot — One bellows boot is located on each side of the EPAS gear assembly. Each boot is held in place with 2 boot clamps. The boots and clamps are available for service, refer to Section 211-02 .
• EPAS gear isolator — One rubber isolator is located on the right rear attaching point of the EPAS gear assembly. The isolator aids in the reduction of NVH concerns and is not available separately for service.

The EPAS system utilizes a rack-and-pinion type steering gear. Power assist is provided by a motor that is connected to the steering rack by a belt and a pulley and bearing assembly. The steering gear and motor/module are serviced as an assembly. A new steering gear includes inner tie rods, however, the inner and outer tie rods can also be serviced separately. For additional information on tie rod end service, refer to Section 211-02 .

That's why they replaced the entire steering rack. However, what does this have to do with advance trac?

 

[Snoopy49]

Maybe this is what ties the steering to AdvanceTrac®?

Anti-Lock Brake System (ABS) and Stability Control

ABS With AdvanceTrac®
The ABS with AdvanceTrac® consists of the following components:

• ABS module — attached to the Hydraulic Control Unit (HCU), but can be serviced separately.
• Front wheel speed sensors — one sensor is located in each front wheel knuckle. The sensors are serviced separately from the knuckle.
• Front wheel speed sensor tone rings — one tone ring is located on each front wheel hub and is serviced separately from the wheel hub.
• HCU — which contains several valves (inlet, outlet, isolation and dump) and the hydraulic pump motor. It is mounted in the LF corner of the engine compartment and can be serviced separately.
• Rear wheel speed sensors — one sensor is located on each end of the rear axle housing. The sensors are serviced separately from the axle housing.
• Rear wheel speed sensor tone rings — one tone ring is located on each axle shaft and is serviced separately from the axle shaft.
• Restraints Control Module (RCM) — located under the rear of the front floor console and contains the yaw rate and lateral accelerometer sensors.
• Power Steering Control Module (PSCM) located in the steering gear, sends steering angle and rotation information to the ABS module.
• Stability/traction control switch — is part of the hazard flasher switch assembly.

Electronic Brake Distribution (EBD)
The ABS module and HCU incorporate a strategy called EBD . The EBD strategy uses the HCU as an electronic proportioning valve to create a balanced braking condition between the front and rear wheels and minimize the chance of rear wheel lockup during hard braking.

Anti-Lock Braking
The ABS aids in the prevention of wheel lock-up during braking events, allowing the driver to maintain steering control and stop in the shortest distance possible under most conditions.

AdvanceTrac® System
The traction control function and the ESC function comprise the AdvanceTrac® system. Some vehicles also offer a launch control function and additional functionality through the use of the stability/traction control switch.

Traction Control System
The traction control system aids in the prevention of excessive wheel spin allowing the vehicle to maintain traction during acceleration.

Electronic Stability Control (ESC) System
The ESC system constantly monitors the direction of travel relative to the driver's intended course, except when the vehicle is traveling in reverse, and aids in keeping the vehicle traveling along that course.

Stability/Traction Control Switch
The stability/traction control switch provides the driver the ability to select one of 4 modes for the AdvanceTrac® system.

Hill Start Assist
Hill start assist supports the driver during drive-off situations on upward gradients. When the driver releases the vehicle brake, hill start assist prevents the vehicle from rolling back in the opposite direction.

Launch Control
The launch control system works in conjunction with the AdvanceTrac® system and PCM to maximize traction from a standing start acceleration in a straight line. Launch control enables a unique "drag start" traction control calibration designed for high grip surfaces. The system allows the driver to set and hold a desired launch RPM depending on tire temperature, surface condition or weather. Unlike the AdvanceTrac® system, the launch control system does not reset to OFF when the ignition is cycled. For information on setting the launch control system, refer to the Owner's Literature.

 

[crucianpilot]

Found the problem. I had removed the ground wire on the right strut tower when adjusting my catch can and forgot to tighten it down. Doh!!!!:bash:

 

[Daffy]

Wow, with these computer base rocket ships it's amazing what can happen with something like a loose ground.

Glad it was an easy fix once you figured it out, scary symptoms I'm sure.

 

[crucianpilot]

Wow, with these computer base rocket ships it's amazing what can happen with something like a loose ground.

Glad it was an easy fix once you figured it out, scary symptoms I'm sure.

Yes, I was very happy it was a simple fix.