A Service Power Steering message may be displayed on the Driver Information Center on some 2017-2023 XT5, Acadia; 2018-2023 Enclave, Traverse; 2019-2023 Blazer; and 2020-2023 XT6 models. DTC P0128 (Engine Coolant Temperature Below Thermostat Regulating Temperature) may be set. However, there may not be any codes set that seem related to the steering system.
If the Engine Control Module (ECM) detects a coolant temperature concern, the Service Power Steering message may be displayed in order to protect the steering gear in the event of an undetected overheating condition. (Fig. 12)
Fig. 12
The power steering control module can detect malfunctions within the electric power steering system. Any malfunction detected that disables steering assist will cause the Service Power Steering message to be displayed. In addition, the power steering control module calculates an internal system temperature, which is used to protect the power steering system from damage caused by high temperature. When the calculated temperature exceeds a pre-determined level, the amount of current commanded to the power steering motor is reduced, resulting in a temporary reduced level of assist. Full assist will return once the calculated temperature drops below the pre-determined level.
To address the condition causing the DIC message to be displayed, diagnose and repair any engine cooling issues related to DTC P0128. After repairs are completed, clear the codes and test drive the vehicle. If the Service Power Steering message returns, follow the diagnostics for any steering conditions in the appropriate Service Information.
For additional information, refer to #PIT5967.
– Thanks to David Goodrow
