C0545 on GMC: How to Diagnose & Fix
Electronic Stability Control Inhibit
1 GMC model · 1 documented issue · 1 critical
C0545 on GMC by model: symptoms, diagnosis and fix
On 2020+ Sierra 3500HD (T1 platform) with GM's electronically controlled hydraulic Digital Steering Assist, owners report intermittent loss of steering assist and warning messages such as "Steering Assist Reduced". NHTSA complaints and GM service information commonly point to power steering control module/software issues, wiring/connector concerns, or steering gear faults that can occur without prior symptoms.
Common Symptoms
- "Steering Assist Reduced" or "Service Power Steering" message
- Heavier steering effort, especially at low speeds
- Intermittent assist loss after startup or during turns
- EPS warning light and stored steering control DTCs
- Assist returns after key cycle
How to Fix
Scan for power steering control module DTCs and follow GM SI diagnostics for the steering gear/module and harness. Perform GM-released software updates/reprogramming when applicable; repair wiring/connectors or replace the steering gear if internal faults are confirmed. Verify battery/charging system health because low voltage can trigger steering assist faults.
Sources for this issue (2)
C0545 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0545 mean on a GMC?
C0545 stands for "Electronic Stability Control Inhibit." This chassis/brake code indicates the electronic stability control (ESC) system has been inhibited, meaning it has temporarily disabled itself because of a related fault or invalid condition. Stability control helps keep the vehicle from skidding by selectively braking wheels and managing engine power, and it relies on inputs like wheel speed, steering angle, and yaw sensors. When one of those inputs is missing or implausible, the system shuts itself off and sets this code. Often it is a secondary code triggered by another underlying fault rather than a problem with stability control hardware itself. On GMC it is documented across 1 model: Sierra 3500HD.
What are the most common causes of C0545?
The most common causes of C0545 are: Faulty or dirty wheel speed sensor, Steering angle sensor fault or needing calibration, Yaw rate / lateral acceleration sensor fault, Low brake fluid or related brake system fault, Damaged wiring or connectors to a sensor, Related ABS/traction control fault setting this as secondary, Faulty ABS/ESC control module. The specific cause varies by vehicle.
How much does it cost to fix C0545 on a GMC?
Repair costs vary widely with the root cause and GMC model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.