Ensure reliable fuel delivery and engine performance with the ‌2204403 Fuel Pump Assembly‌, the ‌genuine OEM replacement‌ for discontinued part ‌2521116‌. This guide covers compatibility, failure symptoms, installation steps, and why OEM assemblies outperform aftermarket alternatives in pressure stability, durability, and system integration for ‌Chevrolet, GMC, and Cadillac trucks/SUVs‌.

Product Overview & Compatibility‌
Part Numbers & Applications‌
2204403‌ (Direct Fit Replacement for 2521116):
Models‌:
Chevrolet Silverado 1500 (2014–2018)‌: 4.3L V6, 5.3L V8 (L83/L8B), 6.2L V8 (L86).
GMC Sierra 1500 (2014–2018)‌: 5.3L EcoTec3, 6.2L Denali.
Cadillac Escalade (2015–2020)‌: 6.2L L86, 6.2L L87.
Function‌: Delivers 58–65 PSI fuel pressure via a brushless electric motor (compatible with flex-fuel systems).
Replaces‌: 2521116, 25332385, 25342735 (obsolete).
Key Features‌:
High-Performance Design‌:
Reinforced nylon housing (resists ethanol corrosion).
150-micron stainless steel inlet filter (prevents debris ingress).
Integrated fuel level sensor (accuracy ±3% full scale).
Plug-and-Play Fitment‌:
Matches OEM fuel pump module dimensions (Ø120mm x 280mm).
Pre-calibrated for factory fuel trim settings (no ECU reprogramming needed).
Technical Comparison: OEM vs. Aftermarket‌
Parameter‌ ‌OEM 2204403‌ ‌Aftermarket Pumps‌
Flow Rate‌ 255 LPH @ 60 PSI 180–220 LPH (lean conditions)
Pressure Stability‌ ±2 PSI under load ±8–10 PSI (triggers P0087/P0191)
Motor Lifespan‌ 150,000+ miles 50,000–80,000 miles
Ethanol Resistance‌ E85 compatible (tested 100,000 cycles) E30 max (seals degrade)
Warranty‌ 3 years/unlimited mileage 1 year/12,000 miles
Symptoms of Failing Fuel Pump Assembly‌
Hard Starting‌: Cranks 5+ seconds before ignition (low fuel pressure).
Engine Stalling‌: Sudden power loss at idle or low RPM.
Whining Noise‌: Loud buzz from fuel tank (worn pump bearings).
Check Engine Light‌: Codes P0087 (low pressure), P0191 (sensor fault).
Poor Fuel Economy‌: MPG drops 15–20% due to inconsistent delivery.
Installation Guide‌
Tools Required‌:
Fuel pressure relief tool, Torx T30, socket set (14mm, 16mm).
Steps‌:
Depressurize Fuel System‌:
Remove fuel pump fuse (#52 in Silverado) and crank engine for 10 seconds.
Access Fuel Pump‌:
Lower fuel tank or remove bed access panel (truck models).
Unbolt locking ring (counterclockwise) with 14mm socket.
Replace Assembly‌:
Disconnect electrical connectors and fuel lines (quick-connect fittings).
Align new 2204403 pump’s arrow with tank markings. Secure ring to ‌35 Nm‌.
Test System‌:
Reconnect battery and prime pump (key to ON x3). Check for leaks.
Where to Buy & Red Flags‌
Trusted Suppliers‌:
GM dealerships, ACDelco Direct, RockAuto OEM Section.
Avoid‌:
Pumps lacking ACDelco/GM logos or UL/SAE certifications.
"Universal" kits requiring wiring modifications.
Maintenance Tips‌
Replace fuel filter every ‌48,000 km‌ (prevents pump strain).
Keep tank ≥1/4 full to avoid overheating the pump.
Use Top Tier detergent gasoline to minimize injector clogs.
FAQ‌

Q: Does 2204403 fit a 2017 Chevy Tahoe 5.3L?‌
A: Yes – Compatible with Tahoe/Suburban 5.3L (2015–2020).

Q: Why does my new pump still throw code P0087?‌
A: Likely a counterfeit unit – Replace with genuine 2204403.

Q: Can I replace the pump without dropping the tank?‌
A: On Silverado/Sierra, use bed access panel (no tank removal).

Q: Are aftermarket pumps cheaper?‌
A: Yes, but OEM lasts 2–3x longer and prevents engine damage.

Q: How to test fuel pressure without a gauge?‌
A: Use OBD2 scanner – Live data should show 58–65 PSI at idle.

Conclusion‌

The ‌2204403 Fuel Pump Assembly‌ is the ‌trusted OEM solution‌ for replacing outdated part ‌2521116‌ in Chevrolet, GMC, and Cadillac trucks/SUVs. Engineered for precise pressure control, ethanol resistance, and extended service life, it outperforms aftermarket alternatives prone to premature motor failure, pressure fluctuations, and ethanol degradation. Trust genuine GM engineering to restore fuel system reliability and protect your engine from costly damage.

SEO Keywords‌: 2204403 fuel pump replacement, 2521116 direct fit, Silverado fuel pump symptoms, Sierra 1500 fuel pump install, OEM vs aftermarket fuel pump

This SEO-optimized article targets GM truck/SUV owners experiencing ‌hard starts‌, ‌engine stalling‌, or ‌fuel pressure codes‌. By emphasizing OEM advantages (255 LPH flow, E85 compatibility), it answers searches like “2204403 vs 2521116” or “Silverado P0087 fix.” Step-by-step installation guides cater to DIY repairs, while technical comparisons highlight long-term savings with genuine parts. FAQs address compatibility myths and counterfeit risks, reducing purchase hesitation and reinforcing OEM reliability.