P0122: Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input
5 vehicles · 5 makes · $50-$700 repair
Most Reported On
P0122 is an OBD-II diagnostic trouble code meaning “Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input.” This generic code means the PCM detected a lower-than-expected voltage from the throttle position sensor (or accelerator pedal position sensor) 'A' circuit. This sensor tells the computer how far the throttle/pedal is open so it can manage fuel, timing, and on drive-by-wire systems the throttle itself. A low or lost signal can cause hesitation, surging, poor acceleration, stalling, or limp-home mode, so it should be diagnosed promptly. This code is most commonly reported on 2001-2004 Volvo S60, 2010-2017 GMC Terrain (SLE, SLT, Denali), and 2000-2011 Ford Ranger, plus 2 other vehicles, with repair costs ranging from $50 to $700.
Common Causes
Typical Repair Cost
Based on 5 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0122, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
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)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
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
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
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.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (5)
FAQ
What does P0122 mean?
P0122 stands for "Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input." This generic code means the PCM detected a lower-than-expected voltage from the throttle position sensor (or accelerator pedal position sensor) 'A' circuit. This sensor tells the computer how far the throttle/pedal is open so it can manage fuel, timing, and on drive-by-wire systems the throttle itself. A low or lost signal can cause hesitation, surging, poor acceleration, stalling, or limp-home mode, so it should be diagnosed promptly.
What are the most common causes of P0122?
The most common causes of P0122 are: Faulty throttle position sensor, Short to ground or open in the TPS signal circuit, Damaged or corroded TPS connector, Loss of reference voltage or bad ground to the sensor, Worn throttle body / TPS contacts, Chafed or pinched wiring harness, Faulty PCM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0122?
Repair costs for P0122 range from $50 to $700, depending on the vehicle and root cause.
Which vehicles are affected by P0122?
Au7o has documented P0122 across 5 vehicle models from 5 manufacturers: Chevrolet, Ford, GMC, Jeep, Volvo.
Sources (8)
- articleHere's Why Your GMC Terrain May Have Reduced Engine Power
- ForumGMC Terrain: engine power reduced and check engine light is on
- articleGMC Terrain Throttle Body Guide: Symptoms, Replacement, and Costs (2010-2021)
- Forum'Service Stabilitrak' followed by 'Engine Power is reduced!' - GMC Terrain Forum
- articleThrottle Position Sensor May Fail: Jeep Wrangler — RepairPal
- ForumThrottle position sensor (TPS) went bad, now what? — Jeep Wrangler TJ Forum
- ForumReduced Engine Power and Service Stability Control / Throttle Body issue — Impala Forums
- Forum2011 Chevy Impala - Service Stabilitrak - Reduced Engine Power — Edmunds
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.