P1515 on Chevrolet: How to Diagnose & Fix
Control Module Throttle Actuator Position Performance
1 Chevrolet model · 1 documented issue · 1 critical · $120-$450 repair
P1515 on Chevrolet by model: symptoms, diagnosis and fix
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).
Common Symptoms
- 'Reduced Engine Power' warning message
- Limp mode / severe loss of acceleration
- Hesitation or surging
- Check Engine light with throttle codes
- Intermittent power loss that clears on restart
How to Fix
Retrieve codes to isolate the branch: P1515/P1516 point at the TAC/throttle actuator, P2135/P0120-series at the TPS/APP correlation. Start with the cheap, common causes: clean the electronic throttle body, inspect and repair the throttle-body wiring harness (especially chafed/broken wires) and clean/tighten engine grounds. If the throttle body's internal TPS is faulty, replace the electronic throttle body assembly (ACDelco units available; part roughly $120-300). A failed APP pedal sensor is a less common cause.
Sources for this issue (1)
P1515 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 P1515 mean on a Chevrolet?
P1515 stands for "Control Module Throttle Actuator Position Performance." A General Motors manufacturer-specific code for the Throttle Actuator Control (TAC) / electronic throttle system, which positions the throttle blade electronically instead of by cable. The control module commands the blade to a specific angle, then compares that command against what the throttle position sensors actually report; P1515 sets when the actual position does not match the commanded position. Vehicles commonly drop into Reduced Engine Power mode and the throttle may feel dead or hesitant. Because the vehicle can lose power in traffic, this should be addressed promptly. On Chevrolet it is documented across 1 model: Tahoe.
What are the most common causes of P1515?
The most common causes of P1515 are: Poor connection or corrosion at the throttle body / Throttle Actuator Control (TAC) module connector, Faulty TAC module, Failed throttle position (TPS) sensor or throttle body actuator motor, Dirty or carbon-fouled throttle body causing the blade to stick, Damaged wiring between the control module and the throttle body, Failed accelerator/throttle pedal position (APP/TPP) sensor, Failed ECM/PCM (rare — verify the throttle body and wiring first). The specific cause varies by vehicle.
How much does it cost to fix P1515 on a Chevrolet?
Published repair estimates on Chevrolet range from $120 to $450 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P1515 on a different make?
View P1515 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.