P0120 on Chevrolet
Throttle/Pedal Position Sensor Circuit Malfunction
P0120 on Chevrolet vehicles indicates throttle/pedal position sensor circuit malfunction. Au7o has documented this code across 1 Chevrolet model — most commonly on Tahoe. This code indicates a malfunction in the throttle position or accelerator pedal position sensor circuit. These sensors tell the computer how far the throttle plate is open or how far you've pressed the pedal, which the computer uses to control engine power and, on drive-by-wire systems, the throttle itself. When the signal is out of range, erratic, or doesn't make sense relative to other inputs, P0120 sets. Symptoms can include hesitation, surging, stalling, or the vehicle entering a reduced-power 'limp' mode for safety. Typical repair costs on Chevrolet range from $120 to $450, depending on the specific model and root cause.
Common Causes of P0120
- •Failed throttle position sensor
- •Corroded or loose TPS/pedal sensor connector
- •Damaged or shorted sensor wiring
- •Carbon buildup or a sticking throttle body
- •Worn throttle body or throttle plate
- •Poor sensor reference voltage or ground
- •Faulty accelerator pedal position sensor
- •Faulty PCM/ECM (rare)
P0120 on Chevrolet by Model
Chevrolet Tahoe(1 issue)
- 'Reduced Engine Power' Limp Mode - Electronic Throttle (TAC) System2000-2010
Tahoes with drive-by-wire throttle (APP pedal sensor + TAC module + electronic throttle body) commonly trigger a 'Reduced Engine Power' message and drop into limp mode with severely limited acceleration - a safety concern in traffic. On GMT800s the frequent culprits are a broken/chafed wire in the throttle-body harness (often the yellow wire), corroded engine grounds, or a dirty/sticking throttle body (P1516/P1515). GMT900s see similar throttle-actuator/APP faults (P2101/P2135/P0120 family).
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View P0120 across all makes →Frequently Asked Questions
What does P0120 mean on Chevrolet?▼
P0120 stands for "Throttle/Pedal Position Sensor Circuit Malfunction." This code indicates a malfunction in the throttle position or accelerator pedal position sensor circuit. These sensors tell the computer how far the throttle plate is open or how far you've pressed the pedal, which the computer uses to control engine power and, on drive-by-wire systems, the throttle itself. When the signal is out of range, erratic, or doesn't make sense relative to other inputs, P0120 sets. Symptoms can include hesitation, surging, stalling, or the vehicle entering a reduced-power 'limp' mode for safety. On Chevrolet specifically, this code is documented across 1 model.
What causes P0120 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed throttle position sensor, Corroded or loose TPS/pedal sensor connector, Damaged or shorted sensor wiring, Carbon buildup or a sticking throttle body, Worn throttle body or throttle plate. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0120 on a Chevrolet?▼
Repair costs on Chevrolet range from $120 to $450, depending on the specific model and root cause.
Which Chevrolet models have P0120 documented?▼
Au7o has documented P0120 on 1 Chevrolet model: Tahoe.