2012 Jeep Grand Cherokee Fuel Pump Relay Location: The Definitive Guide

Finding the fuel pump relay on your 2012 Jeep Grand Cherokee is straightforward: it resides inside the Totally Integrated Power Module (TIPM)**, located in the engine compartment near the battery. The specific relay position is Cavity 70 within the TIPM.**

If your 2012 Grand Cherokee cranks but won't start, or exhibits sputtering and loss of power consistent with fuel starvation, a failing fuel pump relay is a prime suspect. Knowing exactly where to find it and how to access it is the crucial first step towards diagnosis and repair. This guide provides detailed, step-by-step information on locating, identifying, testing, and replacing this vital electrical component in your Jeep.

Why the Fuel Pump Relay is Critical

The fuel pump relay serves as the primary electrical switch controlling power to your Grand Cherokee's fuel pump. Its function is fundamental:

  1. High Current Control: The fuel pump requires substantial electrical current to operate. The ignition switch and vehicle computer cannot safely handle this load directly. The relay acts as an intermediary, using a small control circuit (from the Powertrain Control Module - PCM) to switch the much larger current flow needed by the fuel pump.
  2. Safety & Control: The relay prevents the ignition switch from overheating or being damaged by the fuel pump's electrical demand. It also allows the PCM precise control over when the fuel pump runs, primarily during the prime cycle (key turned to "ON" before starting) and while the engine is running or cranking.
  3. System Protection: A properly functioning relay ensures the fuel pump only operates when intended, preventing potential drain or fire hazards. If the relay fails, fuel delivery stops entirely or becomes intermittent, preventing the engine from starting or running properly.

Recognizing Symptoms of a Faulty Fuel Pump Relay

When the fuel pump relay malfunctions, symptoms mimic other fuel delivery problems. However, relay issues often present with distinct characteristics:

  1. Engine Cranks but Won't Start: This is the most common symptom. Turning the key activates the starter motor, but the engine never catches and runs because the fuel pump receives no power and cannot supply fuel to the engine. Important: This symptom overlaps with failed fuel pumps, severe fuel line blockages, ignition problems, or security system issues.
  2. Sudden Engine Stalling: While driving, an immediate and complete loss of power occurs when the relay cuts out, causing the engine to die as if the ignition was turned off. The engine will likely crank but not restart afterward.
  3. Intermittent Starting Issues: The vehicle starts normally some days but fails completely on others. Sometimes turning the key off and back on repeatedly might eventually result in the fuel pump priming and the engine starting. This points towards an internal relay failure where contacts are intermittently making connection.
  4. No Fuel Pump Priming Sound: A key indicator! When you first turn the ignition switch to the "ON" position (without cranking), you should hear a distinct humming or buzzing sound from the rear of the vehicle (where the fuel pump is located inside the tank) for about 2-3 seconds. The complete absence of this sound during multiple key cycles strongly suggests a problem with relay power, the fuse, wiring, or the pump itself. The relay is the first logical component to check if the fuse is good. You might also hear a faint click from the TIPM when turning the key on if the relay is attempting to engage.
  5. Check Engine Light (Possible): While not guaranteed, a completely failed relay might trigger diagnostic trouble codes (DTCs) related to fuel pressure or fuel delivery if the PCM detects an issue downstream. However, a simple relay failure often won't set a specific DTC.

Locating the TIPM in Your 2012 Grand Cherokee

The Totally Integrated Power Module (TIPM) is the centralized hub for numerous electrical circuits in the vehicle, housing the vast majority of fuses and relays. It is securely mounted in the engine compartment.

  1. Open the Hood: Ensure the vehicle is in Park with the parking brake engaged, then pull the hood release lever inside the cabin and secure the hood safely open.
  2. Position: Stand facing the engine compartment.
  3. Identify: Look to the left side (driver's side) of the engine bay. The TIPM is a large, usually black plastic box, located directly against the back wall (near the windshield firewall) but positioned on the driver's side.
  4. Near the Battery: It sits just inboard and slightly behind the vehicle's primary 12-volt battery. You might need to slightly lean over the battery or look behind its top edge.
  5. Shape: It resembles a sophisticated fuse box, typically rectangular or complexly shaped, often with a removable cover.
  6. Cover: The TIPM has a protective cover that clips in place. This cover needs to be removed to access the internal fuses and relays.

Accessing Cavity 70: The Fuel Pump Relay Position

Once you've located the TIPM, finding Cavity 70 requires attention:

  1. Remove the TIPM Cover: Release the plastic retaining clips located around the perimeter of the TIPM cover. Gently pry or unclip each one. Lift the cover straight up to remove it completely. Set it aside carefully.
  2. Locate the Relay Cavities: With the cover off, you'll see an array of slots containing fuses and relays. Fuses are smaller plastic components (often blade-style), while relays are larger, typically cube-shaped components (often black, grey, or clear). These slots are organized into rows and columns, often labeled numerically or alphanumerically on the TIPM housing.
  3. Locate Cavity Numbering: Crucial Step: Printed directly on the TIPM plastic housing, usually very close to each cavity, are identification numbers (e.g., "68", "69", "70", "71"). This numbering is essential for identifying the correct relay position. You may need to look carefully; sometimes the numbers are small or molded into the plastic. Alternatively, diagrams printed inside the removed TIPM cover or in the owner's manual can confirm the numbering layout.
  4. Find Cavity 70: Systematically scan the numbering around the relay cavities until you find the slot labeled "70". In the 2012 Grand Cherokee TIPM, this specific slot houses the fuel pump relay.
  5. Identify the Relay Itself: The relay in Cavity 70 will typically be identical in size and shape to many surrounding relays (often 5-pin miniature ISO relays). A genuine Mopar relay may have a Chrysler Pentastar logo. Color alone is not a reliable identifier as colors can vary, but OEM replacements are often black.

Important Note on Relay Cavities: While Cavity 70 is the definitive location for the fuel pump relay in the 2012 model year Grand Cherokee, adjacent cavities (like 68, 69, 71) often contain other relays. Mistaking one for the fuel pump relay is a common error. Always rely on the cavity numbering stamped on the TIPM itself, not on relay color or position relative to other relays.

Tools Needed for Testing and Replacement

Before handling any electrical components, ensure safety by turning the ignition off and removing the key. Disconnect the negative terminal of the vehicle battery to eliminate the risk of shorts or electrical shock.

  1. Basic Tools: Needle-nose pliers or standard pliers may be helpful for gripping relays, but fingers often suffice.
  2. Replacement Relay: If testing confirms failure, you'll need a compatible replacement. Options include:
    • OEM Mopar Relay: Available from Jeep dealership parts counters. Part number may vary slightly; provide your VIN for exact matching. Typically offers high reliability.
    • Aftermarket Equivalent: Standard ISO mini relay, typically 5-pin (ISO 280), rated for 20/30A or higher. Readily available at auto parts stores (NAPA, AutoZone, Advance Auto Parts, O'Reilly's, etc.), online retailers (RockAuto, Amazon), or electronics suppliers. Ensure it matches the pin configuration and ratings. Ensure the relay matches the socket type (usually 5-pin miniature "ISO" relay).
  3. Multimeter (Voltmeter): Essential for accurate testing. A basic digital multimeter capable of measuring DC Voltage (20V scale) and Resistance (Ohms - Ω) is sufficient.
  4. Fuse Puller (Optional): Often included in the original vehicle toolkit or sold with fuse kits. Helps remove the fuel pump fuse safely if needed during testing.
  5. Owner's Manual: For reference diagrams of the TIPM layout and fuse listings.

Step-by-Step Relay Testing Procedure

Testing the relay itself is the most reliable way to confirm failure before replacement.

Safety Reminder: Disconnect the negative battery cable before proceeding to prevent electrical shorts and potential injury.

  1. Locate Fuel Pump Fuse: Identify and inspect the 20-amp fuel pump fuse. This fuse is also located within the TIPM. Consult your owner's manual or the diagram printed on the inside of the TIPM cover to find its exact cavity. This fuse protects the same circuit as the relay. Visually inspect the fuse. If the metal strip inside is visibly broken or melted, the fuse is blown and must be replaced. A blown fuse can cause symptoms identical to a bad relay and can be blown because of a failing relay or fuel pump. If blown, replace it with an identical 20-amp fuse first (after identifying and fixing the root cause if possible).
  2. Physical Inspection: Remove the relay from Cavity 70. Pull it straight up with gentle, even pressure. It may fit snugly. Examine the relay's plastic housing and pins. Look for signs of melting, burning, cracking, or corroded terminals. Any obvious physical damage means the relay is faulty.
  3. Listen for Audible Click Test: With the relay removed and the battery still disconnected, you can perform a basic click test once power is restored.
    1. Reconnect the negative battery cable securely.
    2. Hold the relay firmly in your hand.
    3. Have a helper slowly turn the ignition switch to the "ON" position (not "START").
    4. Listen: You should hear and feel a distinct click inside the relay as it attempts to energize. This indicates the internal electromagnet coil is likely functional. If you get no click at all during ignition ON, it points strongly towards a faulty relay coil or a problem with the control signal from the PCM. Note: A click only confirms the coil is energizing; it does not confirm that the contact points inside are actually passing current. A relay can click but still be faulty.
  4. Multimeter Testing (Ohms - Coil Resistance): Tests the integrity of the relay's internal electromagnet.
    1. Set your multimeter to measure Resistance (Ohms - Ω).
    2. Identify the relay coil terminals. On a standard 5-pin ISO mini relay (common in TIPMs), these are typically pins 85 and 86. They are usually the only pair connected to a low-current circuit. Locate these pins by looking at the bottom of the relay; the numbers are often molded into the plastic base near each pin. Consult a relay pinout diagram if unsure (readily found online).
    3. Place one multimeter probe on pin 85 and the other on pin 86.
    4. Result: You should measure a resistance value within a specific range. Typically, for auto relays, this falls between 50 to 120 Ohms. A reading significantly outside this range (e.g., OL/open circuit or 0 Ohms/short circuit) indicates a problem with the coil.
  5. Multimeter Testing (Ohms - Contact Continuity): Tests whether the relay's switch contacts are functioning and not burnt or stuck open.
    1. Set multimeter to Continuity (if available) or Resistance (Ohms) again.
    2. Identify the relay's main switch terminals. On a standard 5-pin ISO relay, these are typically pins 30 and 87. Pin 30 is the common input (usually connected to battery power via the fuse), pin 87 is the normally-open output (connected to the load, like the fuel pump).
    3. Place one probe on pin 30, the other on pin 87.
    4. Baseline: With the relay off (not energized - sitting on your workbench), there should be NO CONTINUITY (infinite resistance, OL reading). The switch is open.
    5. Energize the Coil: Now, apply 12 volts to the coil pins (85 and 86). You can:
      • Use a spare 9-volt battery (touch leads to pin 85 (+) and 86 (-)).
      • Use jumper wires from the vehicle battery (connect red jumper to battery positive, black to relay pin 85; connect another black jumper to battery negative, black to relay pin 86). Be extremely careful not to short wires. Some relays have diode protection requiring correct polarity (pin 86 usually positive, pin 85 negative).
    6. With the coil energized (you should hear/feel a click), retest pins 30 and 87.
    7. Result: You should now measure CONTINUITY (very low resistance, near 0 Ohms). The switch is closed. If continuity remains absent after energizing, or if continuity exists without energizing (indicating welded or shorted contacts), the relay contacts are faulty.

If either the coil test or the contact continuity test fails, the relay is defective and needs replacement.

Step-by-Step Relay Replacement

  1. Verify Replacement: Ensure you have the correct replacement relay.
  2. Safety First: Turn ignition off, remove key. Disconnect the negative battery terminal.
  3. Remove Old Relay: Locate Cavity 70 again. Pull the old relay straight out. It should come out with firm, steady pressure. Wiggle slightly if stuck.
  4. Inspect Socket: Briefly check the relay socket cavity (Cavity 70). Look for any signs of melted plastic, corrosion on the metal contacts, or bent pins. Do not force anything into a damaged socket.
  5. Install New Relay: Align the new relay correctly. The pins are keyed, but look closely to match the relay's pin pattern exactly with the socket pattern. Gently but firmly press the relay straight down into Cavity 70 until it seats completely. It should click into place or feel securely seated. Do not apply excessive force.
  6. Reconnect Battery: Securely reconnect the negative battery cable.
  7. Test: Turn the ignition key to the "ON" position. Listen for the fuel pump prime cycle (2-3 second hum/buzz from the rear). This sound returning is a strong sign of success.
  8. Crank Engine: Attempt to start the engine. If it starts and runs normally, the repair was successful.
  9. Reinstall TIPM Cover: Once everything is confirmed working, securely clip the TIPM cover back in place.

Important Considerations and Variations

  1. Model Year Consistency: The location (TIPM Cavity 70) is consistent for the 2012 Jeep Grand Cherokee. Earlier WJ models (pre-2005) had different fuse/relay box layouts. Later WK2 models (roughly 2014+) sometimes see TIPM revisions, but 2012 specifically uses Cavity 70. If unsure, the cavity number on the TIPM itself is the ultimate authority.
  2. Common Confusion: The Automatic Shutdown (ASD) Relay is a different but crucial relay, often also located near the fuel pump relay in the TIPM (sometimes Cavity 69 or another position). Malfunction of the ASD relay can also cause no-starts, but it affects ignition and injectors in addition to the fuel pump. They are separate circuits controlled separately by the PCM.
  3. Fuel Pump vs. Relay vs. Fuse: Remember the system:
    • Battery Power --> 30A Fuel Pump Fuse (inside TIPM) --> Fuel Pump Relay Contacts (Cavity 70) --> Wiring --> Fuel Pump.
    • PCM Signal --> Fuel Pump Relay Coil (Cavity 70).
      Failure at any point in this chain (fuse, relay coil, relay contacts, wiring, pump) will stop fuel delivery. The fuse and relay are the easiest and cheapest components to check first.
  4. Aftermarket Relay Quality: While inexpensive generic ISO relays usually work, genuine Mopar relays offer maximum compatibility and longevity. Avoid extremely cheap, unbranded relays.
  5. Safety Paramount: Working on fuel systems carries inherent risks. If symptoms persist after confirming the fuse and relay are good, or if you are uncomfortable performing these diagnostics, seek assistance from a qualified automotive technician. Electrical shorts or mishandling components can lead to vehicle damage or personal injury.

Understanding the precise location and function of the 2012 Jeep Grand Cherokee's fuel pump relay in Cavity 70 of the TIPM empowers you to tackle one of the most common causes of non-starting or engine stalling. By following the identification, testing, and replacement procedures outlined here, you can potentially resolve the issue quickly and cost-effectively, restoring your Grand Cherokee to reliable operation. Always prioritize safety and consult a professional if unsure.