P2138 on Chevrolet
Throttle/Pedal Position Sensor D/E Voltage Correlation
P2138 on Chevrolet vehicles indicates throttle/pedal position sensor d/e voltage correlation. Au7o has documented this code across 1 Chevrolet model — most commonly on Avalanche. This code means the two (or three) signals from the accelerator pedal position / throttle position sensors disagree with each other — specifically sensors 'D' and 'E', which are typically the redundant signals built into the electronic accelerator pedal. Drive-by-wire systems use multiple sensors that should track together so the computer can trust the driver's input; when their voltages don't correlate, the computer can't be sure of the requested throttle and sets this code. As a safety response it usually puts the engine into a reduced-power 'limp' mode. It generally points to the pedal sensor assembly or its wiring. Typical repair costs on Chevrolet range from $100 to $500, depending on the specific model and root cause.
Common Causes of P2138
- •Faulty accelerator pedal position sensor assembly
- •Corroded or loose pedal sensor connector
- •Chafed, shorted, or open wiring between pedal and ECM
- •Shorted-together signal wires in the pedal harness
- •Poor sensor ground or reference voltage
- •Moisture or contamination in the pedal connector
- •Faulty ECM/PCM (less common)
P2138 on Chevrolet by Model
Chevrolet Avalanche(1 issue)
- Reduced Engine Power Mode from Throttle Body and Pedal Sensor Faults2007-2013
The 2007-2013 Avalanche frequently enters "Reduced Engine Power" mode, severely limiting acceleration. The most common causes are the electronic throttle body wearing out or the accelerator pedal position sensor (APP sensor) developing faults. The vehicle becomes barely drivable in this mode, struggling to accelerate to highway speeds. The issue can occur intermittently before becoming permanent.
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View P2138 across all makes →Frequently Asked Questions
What does P2138 mean on Chevrolet?▼
P2138 stands for "Throttle/Pedal Position Sensor D/E Voltage Correlation." This code means the two (or three) signals from the accelerator pedal position / throttle position sensors disagree with each other — specifically sensors 'D' and 'E', which are typically the redundant signals built into the electronic accelerator pedal. Drive-by-wire systems use multiple sensors that should track together so the computer can trust the driver's input; when their voltages don't correlate, the computer can't be sure of the requested throttle and sets this code. As a safety response it usually puts the engine into a reduced-power 'limp' mode. It generally points to the pedal sensor assembly or its wiring. On Chevrolet specifically, this code is documented across 1 model.
What causes P2138 on Chevrolet vehicles?▼
Common causes on Chevrolet: Faulty accelerator pedal position sensor assembly, Corroded or loose pedal sensor connector, Chafed, shorted, or open wiring between pedal and ECM, Shorted-together signal wires in the pedal harness, Poor sensor ground or reference voltage. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2138 on a Chevrolet?▼
Repair costs on Chevrolet range from $100 to $500, depending on the specific model and root cause.
Which Chevrolet models have P2138 documented?▼
Au7o has documented P2138 on 1 Chevrolet model: Avalanche.