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2006 chrysler 300c 5 7 fuel pump relay location net worth

📅 October 31, 2026📖 Verified Publication
```html 2006 Chrysler 300C 5.7 HEMI Fuel Pump Relay Location – Complete Guide

2006 Chrysler 300C 5.7 HEMI Fuel Pump Relay Location: The Definitive Guide

The 2006 Chrysler 300C equipped with the 5.7L HEMI V8 (Engine Code: NG) is one of the most recognizable American sedans of its era. Among the most frequently searched diagnostic queries for this platform is the fuel pump relay location—a component that, when faulty, can leave even a perfectly healthy tank of fuel completely inaccessible to the engine. This guide provides a thorough, data-driven analysis of the relay's position, function, common failure modes, and replacement protocol.

Key Takeaways

  • Primary location: The fuel pump relay on the 2006 Chrysler 300C 5.7L HEMI is housed inside the Under-Hood Module (UDM), also called the Power Distribution Center (PDC), located in the engine bay on the driver's side near the battery.
  • relay designation: Within the UDM cover diagram, the fuel pump relay is labeled "FUEL PUMP" or "FP"—typically occupying one of the large rectangular relay slots.
  • Common symptom: A failed fuel pump relay typically causes a no-start condition with no crank Complaint, or intermittent stalling while driving, because the Engine Control Module (ECM) loses power to the pump circuit.
  • Diagnostic shortcut: Swap the fuel pump relay with an identical relay in the UDM (such as the A/C clutch relay) to test—many 300C relays share the same 40A/30A OEM part number (04878085AB or equivalent).
  • Aftermarket cost: OEM or quality aftermarket replacement relays range from $12–$35, while professional diagnosis and labor typically add $80–$150.

Understanding the 2006 Chrysler 300C 5.7L HEMI Electrical Architecture

Before locating the fuel pump relay, it is essential to understand the vehicle's power distribution architecture. The 2006 300C uses a Centrally Mounted Under-Hood Module (UDM) that consolidates multiple functions into a single weathersealed box:

  • Power Distribution Center (PDC): Houses fuses and relay sockets for engine, chassis, and accessory circuits.
  • Integrated Relay Blocks: Several large relays—including the fuel pump relay—are socketed directly into the UDM rather than being independently mounted.
  • ECM Integration: The Engine Control Module (ECM) controls the fuel pump relay coil through a ground-side switch, meaning the relay is an active component in the ECM's fuel delivery strategy.

This integrated design is a known service challenge: unlike older vehicles where relays are individually accessible under the dash, the 300C's UDM requires partial engine-bay disassembly for relay extraction in many cases.

Precise Fuel Pump Relay Location

Under-Hood Module (UDM) / Power Distribution Center

The fuel pump relay is located within the Under-Hood Module, which is positioned on the driver's side of the engine compartment, adjacent to the battery and the brake master cylinder reservoir. To access it:

  1. Open the hood and secure it with the prop rod.
  2. Locate the black rectangular plastic box (approximately 12" × 8" × 4") mounted near the front of the firewall on the driver's side.
  3. Remove the four plastic push-clips or screws securing the UPPER cover of the UDM.
  4. Lift the cover—the relay placement diagram is printed on the underside of this cover for reference.
  5. Identify the relay socket labeled "FUEL PUMP" or "FP" on the diagram.

Relay Specifications

  • Relay type: ISO standard automotive relay (rectangular, 4-pin or 5-pin configuration depending on variant)
  • Part number (OEM equivalent): 04878085AB / 56024729 / 04887050AA
  • Pin configuration: 85 (coil ground), 86 (coil power), 30 (battery feed), 87 (output to pump), 87a (common/alternate — some variants)
  • Current rating: Typically 30A continuous for the fuel pump circuit

Symptoms of a Failing Fuel Pump Relay

Recognizing the signs of relay degradation can prevent roadside breakdowns and unnecessary parts replacement. The following symptoms are documented across Chrysler 300C service bulletins and owner forums:

  • No-crank no-start: The engine cranks normally but will not fire; fuel pressure reads 0 PSI at the rail.
  • Intermittent stalling: The vehicle dies while driving, often restarting after cooling for 10–15 minutes (thermal expansion breaks the internal contact).
  • Loss of fuel pump prime: Key-on engine-off (KOEO) does not produce the usual 2–3 second pump whine from the rear tank area.
  • Check Engine Light with P-code: Codes such as P0087 (Fuel Rail/System Pressure Too Low) or P0463 (Fuel Level Sensor - Intermittent, indirectly related) may set.
  • Relay click absent: No audible click from the UDM when the key is turned to ON, indicating the coil is not energizing.

Step-by-Step Testing Procedure

Tools Required

  • Digital multimeter (DMM)
  • Test light or 12V probe
  • Relay test socket (optional but recommended)
  • Owner's manual or UDM cover diagram

Procedure

  1. Verify battery voltage: Ensure the battery reads ≥12.4V at rest. Low voltage can mimic relay failure.
  2. Locate the fuel pump relay in the UDM using the cover diagram.
  3. Listen for the relay click: Have an assistant turn the key to ON (do not crank). You should hear a distinct click from the UDM within 2 seconds. Absence of a click suggests a relay or coil issue.
  4. Swap test: Remove the fuel pump relay and swap it with an identical relay (e.g., horn or A/C relay). If the vehicle starts, the original relay is faulty.
  5. Ohmmeter coil test: Measure resistance between pins 85 and 86. A healthy relay typically reads 50–120 ohms. An open circuit (∞) indicates a burned coil.
  6. Continuity test (contacts): With