C0321 on 2000-2013 Chevrolet Silverado 1500 — Range Actuator Lock Control Circuit (Transfer Case)
1 vehicles · 1 makes · $250-$1,200 repair
Most Reported On
C0321 is an OBD-II diagnostic trouble code meaning “Range Actuator Lock Control Circuit (Transfer Case).” This GM code relates to the range/lock control circuit of the transfer case encoder/actuator that shifts the vehicle between 2WD and 4WD modes. The control module detected a fault in the circuit that controls or monitors the actuator's locking/range position. Symptoms typically include a 'Service 4WD' message, inability to change between 2WD and 4WD, or unusual transfer-case behavior. This affects four-wheel-drive operation rather than braking, so the danger is loss of 4WD function rather than an immediate brake hazard. This code is most commonly reported on 2000-2013 Chevrolet Silverado 1500, with repair costs ranging from $250 to $1,200.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose C0321, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
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A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
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BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
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- Smog check readiness
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LAUNCH CRP123X OBD-II Scanner
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A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
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Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
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- Oil reset, EPB, BMS, TPMS, injector coding
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FAQ
What does C0321 mean?
C0321 stands for "Range Actuator Lock Control Circuit (Transfer Case)." This GM code relates to the range/lock control circuit of the transfer case encoder/actuator that shifts the vehicle between 2WD and 4WD modes. The control module detected a fault in the circuit that controls or monitors the actuator's locking/range position. Symptoms typically include a 'Service 4WD' message, inability to change between 2WD and 4WD, or unusual transfer-case behavior. This affects four-wheel-drive operation rather than braking, so the danger is loss of 4WD function rather than an immediate brake hazard.
What are the most common causes of C0321?
The most common causes of C0321 are: Faulty transfer case encoder motor/actuator, Worn or damaged transfer case shift motor, Damaged wiring or connector to the actuator, Corroded transfer case control module connector, Failing transfer case control module (TCCM), Low voltage or poor ground to the actuator, Mechanical binding inside the transfer case. The specific cause varies by vehicle.
How much does it cost to fix C0321?
Repair costs for C0321 range from $250 to $1,200, depending on the vehicle and root cause.
Which vehicles are affected by C0321?
Au7o has documented C0321 across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.