| Subject: | Normal Operating Characteristics of Electric Power Steering (EPS) System During Extended Lock-to-Lock Turns (Maximum Steering Wheel Rotation) and/or DTCs C0176 and C0476 Set |
| Models: | 2004-2008 Chevrolet Malibu, Malibu Maxx (excluding 2006-2007 SS and 2007 Maxx models) |
| 2005-2008 Chevrolet Cobalt, Equinox |
| 2005-2008 Pontiac G6 (excluding 2006-2007 GTP, 2006-2008 Convertible and 2007-2008 GT models) |
| 2005-2006 Pontiac Pursuit (Canada Only) |
| 2006-2008 Pontiac Torrent |
This bulletin is being updated with the 2008 model year. Please discard Corporate Bulletin Number 06-02-32-002B (Section 02 - Steering).
The purpose of this bulletin is to inform technicians of normal operating characteristics of the electric power steering system (EPS) when the steering wheel is turned in either direction for an extended period of time.
When the steering wheel is turned to its maximum rotation, the power steering control module (PSCM) will command the maximum amount of current to the EPS motor. If the steering wheel is held in this position for an extended period of time, the PSCM will
go into overload protection mode to avoid system thermal damage. In this mode, the PSCM will limit the amount of current commanded to the EPS motor, which reduces steering assist levels.
If the PSCM detects a high system temperature and the overload protection mode is invoked, DTC C0176 "System Thermal Error" may be set. On some models, DTC C0476 "Electric Steering Motor Circuit Range/Performance" may also be set.
These DTCs indicate normal PSCM action (reduced steering assist) to prevent thermal damage to power steering system components.
Refer to Power Steering System Description and Operation in SI or the appropriate Service Manual for more information about this and other vehicle-specific information on electric power steering systems.
For customer inquiries regarding this characteristic, please refer to the Steering section under Driving Your Vehicle in the appropriate Owner Manual (reproduced below for reference).
Owner Manual Information
If you turn the steering wheel in either direction several times until it stops, or hold the steering wheel in the stopped position for an extended amount of time, you may notice a reduced amount of power steering assist. The normal amount of power steering
assist should return shortly after a few normal steering movements.
