P0221 on Cadillac: How to Diagnose & Fix
Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance
1 Cadillac model · 1 documented issue · 1 critical
P0221 on Cadillac by model: symptoms, diagnosis and fix
On some 2008-2011 CTS models the throttle-position sensor can cause the engine to run rough, illuminate the check engine light and/or an engine reduced power message, and reduce engine power. GM recognized the condition with Special Coverage Adjustment 14582, which covered it for 10 years / 120,000 miles from the original in-service date, whichever came first, regardless of ownership.
Common Symptoms
- Engine Power Reduced message on the DIC
- Loss of engine power
- Check engine light
- Engine runs rough
How to Fix
Diagnose the throttle-control fault and inspect its connectors and wiring before replacing parts. For VIN-eligible 2008–2011 CTS vehicles, GM special coverage 14582 applies when DTC P2135, P0121 or P0221 is set and distinguishes Bosch throttle-body replacement from a Hitachi TPS sensor-kit repair; replace a Hitachi assembly only if the kit does not correct the condition. Coverage was limited to 10 years or 120,000 miles from original in-service date, whichever came first. Ask a dealer to verify applicability and any remaining coverage; do not assume a free repair or replace the accelerator pedal without its own diagnosis.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (1)
P0221 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 P0221 mean on a Cadillac?
P0221 stands for "Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance." This code means the second throttle or accelerator pedal position sensor (circuit B) is sending a signal that is out of the expected range or does not track properly with the other sensor. Modern drive-by-wire systems use redundant sensors, and the computer compares them for agreement. When sensor B's voltage is implausible or inconsistent, this code sets. It can cause hesitation, surging, reduced power, or a forced limp mode for safety. On Cadillac it is documented across 1 model: CTS.
What are the most common causes of P0221?
The most common causes of P0221 are: Faulty throttle position sensor (sensor B), Faulty accelerator pedal position sensor, Dirty or worn throttle body, Wiring or connector problems (corrosion, chafing), Poor ground or reference voltage to the sensor, Intermittent open or short in the signal circuit, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0221 on a Cadillac?
Repair costs vary widely with the root cause and Cadillac 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.