2015 Silverado 1500 Service StabiliTrak and Heavy Steering C0450-03

Question

My steering suddenly got very heavy while pulling into a parking spot today, and the Service StabiliTrak message popped up on the DIC. I checked the fluid level but then remembered this is an Electric Power Steering rack. I'm getting a C0450 code on my scan tool and I can't clear it.

backyard_bart · Accepted Answer

The issue was caused by a corroded ground wire at the G218 location under the dashboard, but specifically, the main EPS power cable where it connects to the battery distribution block had high resistance due to a hairline crack in the terminal. I replaced the positive battery cable assembly (GM Part #23223030) which cost about $115, cleaned the frame grounds thoroughly, and the steering assist returned immediately. Torque the 13mm nuts on the distribution block to 15 lb-ft to ensure a solid connection.

Sarah Thompson · Answer

Check the battery voltage while the engine is running. These EPS racks are extremely sensitive to voltage drops, and if your alternator is puting out less than 13.5V under load, the PSCM will throw a C0450 and shut down assist to protect the motor.

Megan Rivera · Answer

You should inspect the wiring harness connector at the steering rack itself. They are known for getting moisture inside the 2-pin high-current power plug which causes corrosion on the pins. Disconnect it, look for green crusties, and use some electrical contact cleaner.

Jordan Lee · Answer

Is the code for low voltage or internal circuit failure? If it's the internal motor sensor, you might be looking at a steering rack replacement as the Power Steering Control Module is integrated into the rack assembly on these trucks.

2015 Silverado 1500 Service StabiliTrak and Heavy Steering C0450-03

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