P2122 on Chevrolet Impala
Throttle/Pedal Position Sensor/Switch D Circuit Low
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Chevrolet Impala context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for P2122.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What P2122 Means on Your Chevrolet Impala
P2122 is a diagnostic trouble code indicating: Throttle/Pedal Position Sensor/Switch D Circuit Low. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Chevrolet Impala Owner Reports
Source: NHTSA Complaints Database
"Vehicle serviced by firestone complete auto care, november, december 2016 vehicle was in motion, on a city street vehicle exhibited reduced engine power, ran rough, triggered engine error alarm."
"My name is [xxx] and i purchased a 2009 chevy impala, with 123,000 miles on it, in august 2015 from mac churchill auto mall in bedford, texas. i have had no problems with this car since its purchase until november 29th."
"I-40 east bound; 60 mph; coming down a 4 to 7% grade through the smokey mountains, north carolina side; 1st error: "service traction control, reduced engine power, service engine. approximately 5 minutes later 2nd error: "starting disable,service throttle" lost all power to vehicle."
"Service stabilitrak message displayed and reduced engine power to 0 mph while driving. Throttle body, Accelerator pedal position sensor (whole pedal assembly), and ecm replaced. Issue continues. P2138, P2122, P2127 codes present. Stonebriar chevrolet incompetent to resolve."
"The diagnostic revealed that there are 11 codes in the vehicle system. these codes ranged from passkey system failures to evap codes to transmission. suspected failure of wiring harness altogether with possible bcm/cam failure as well."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Chevrolet Impala
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.