Nissan Sunny is a legendary Japanese car that is still popular today due to its reliability and ease of repair. However, even such time-tested machines have weaknesses. One of them is fuel pump relay, the breakdown of which can immobilize the car at the most inopportune moment. Unlike modern cars with dozens of electronic units, Sunny (especially models B13, B14, B15) diagnosing and replacing the fuel pump relay is accessible even to beginners - provided you know where to look and what to do.

This article is not just a retelling of manuals - it contains information from the experience of owners, electricians and mechanics specializing in Nissan 90s and 2000s. We'll figure out how distinguish a relay malfunction from a breakdown of the pump itself or wiringwhere the relay is located in different modifications Sunny, and why sometimes replacing it does not solve the problem. And also typical diagnostic errors that lead to unnecessary spending on spare parts.

Where is the fuel pump relay located? Nissan Sunny?

The location of the relay depends on the year of manufacture and modification of the car. In most cases it can be found in one of two places:

  • 🔧 Fuse and relay box in the passenger compartment - under the instrument panel on the driver's side (typical for B13 and early B14). To gain access, you need to unscrew the plastic cover under the steering wheel or remove the lower part of the dashboard.
  • 🔌 Additional block under the hood — next to the battery or on the left mudguard (typical for B15 and some B14 with engines GA16DE/SR20DE). Look for a black or gray plastic box with a lid.
  • ⚡ Next to the fuel pump - in rare cases, the relay was installed directly on the fuel module bracket (usually on export versions for Asian markets).

To avoid guessing, use a simple rule: the fuel pump relay is in Sunny always located next to main fuse block (usually a 10 amp fuse Fuel Pump). If you find the fuse, the relay will be within 30 cm of it.

📊 What engine is installed in your Nissan Sunny?
  • GA14DE (1.4)
  • GA16DE (1.6)
  • SR20DE (2.0)
  • Other

Signs of a faulty fuel pump relay

Symptoms of a relay failure are often confused with a malfunction of the pump itself or a problem in the fuel system. Here are the key signs that point specifically to the relay:

  • 🚗 Engine won't start, but the starter turns - there is no characteristic buzzing of the fuel pump when the ignition is turned on.
  • ⚡ There is no voltage to the pump (check with a multimeter at the pump connector with the ignition on).
  • 🔄 The engine stalls 2-5 seconds after starting - the relay turns on the pump for a short time, but then turns it off.
  • 💥 Clicking sounds from the relay block when turning the key - a sign of burning contacts inside the relay.

Important: if the pump buzzes, but the engine does not start - the problem is not in the relay, but in the pump itself, filter or fuel lines. Also check fuel pump fuse (often it burns out due to a short circuit in the circuit).

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If the pump does not hum when you turn on the ignition, try lightly tapping the relay with the handle of a screwdriver. If after this the pump starts working, the relay is definitely faulty and requires replacement.

How to check the fuel pump relay Nissan Sunny?

Relay diagnostics take 10-15 minutes and do not require special skills. You will need:

  • 🔧 Screwdriver (for removing the unit cover)
  • 📊 Multimeter (or 12V test lamp)
  • 🔌 Jumper (piece of wire with stripped ends)

Verification algorithm:

  1. Remove the relay from the block (usually it is marked Fuel Pump Relay or has a number 117 on the body).
  2. Check the voltage at the block contacts:
    • Contact 85 (minus) should show 0 V relative to mass.
    • Contact 86 (plus) should show 12 V with the ignition on.
  3. Ring relay contacts:
    • Between 85 And 86 there must be resistance 50-120 Ohm (relay coil).
    • Between 30 And 87 in the off state - ∞ (open), when 12V is supplied to 85-86 — 0 ohm (closed).
  • Check the pump circuit: serve 12V directly to the pump contacts (via a fuse!). If the pump starts working, the relay or its control circuit is to blame.

    • If the relay is working properly, but the pump does not turn on, look for a break in the wiring from the relay to the pump or check crankshaft position sensor (he is also involved in controlling the fuel pump).

    What to do if the relay clicks but the pump does not work?

    This means that the relay coil is activated (there is control), but the power contacts 30-87 do not close. Reasons:

    • The contacts inside the relay are burnt (needs replacement).
    • The relay legs in the block have oxidized (clean the contacts with alcohol).
    • The problem is in the relay ground (check the wire at the contact 85).

    Fuel pump relay connection diagram

    Electrical circuit for controlling the fuel pump in Nissan Sunny typical for most Japanese cars of that time. Below is a simplified diagram for the models B14 with engine GA16DE:

    Relay contact Wire color Purpose Where does it go
    85 Black/white Minus (control) To ground via ECM (control unit)
    86 Red/white Plus (control) From the ignition switch (contact IGN)
    30 Pink Plus permanent From the fuse Fuel Pump (10A)
    87 Green/black Plus for the pump To the fuel pump connector

    Please note: some versions Sunny (for example, with SR20DE) the circuit may differ - there the relay is controlled through immobilizer. If after replacing the relay the pump still does not work, check chip in key and an immobilizer unit.

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    If after turning on the ignition the pump runs for 2-3 seconds and turns off - this is normal! This is how the function of pumping the fuel system is implemented. If the pump does not turn off at all, look for a short circuit in the relay circuit.

    Replacing the fuel pump relay: step-by-step instructions

    The relay replacement procedure takes 5-10 minutes. You only need a new relay (original part number - 25230-31U00 or 25230-31U05 for B15) and a screwdriver.

    Check the fuel pump fuse|Disconnect the negative terminal of the battery|Take a photo of the location of the relay in the block|Prepare a new relay (compare the markings)

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    Replacement steps:

    1. Disconnect the battery (remove the negative terminal) to avoid short circuit.
    2. Remove the relay box cover - it can be secured with latches or screws.
    3. Find the fuel pump relay - it is usually marked, but if not, be guided by the color of the wires (see table above).
    4. Carefully remove the relay - Pull it up, shaking it slightly. Do not use force to avoid breaking the legs!
    5. Install a new relay - it should go in without effort. If the contacts are oxidized, clean them with an eraser or alcohol.
    6. Check your work — connect the battery, turn on the ignition (the pump should hum for 2-3 seconds).

    If the pump does not work after replacing the relay, check:

    • 🔌 fuse (it could burn out due to a short circuit).
    • 🔧 Mass on the body next to the gas tank (often oxidizes).
    • 📊 Pump connector voltage (should be 12V when relay is on).
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    Don't buy cheap Chinese relays! Original Nissan or high-quality analogues (Panasonic, Mitsuba) last 3-5 times longer and do not burn.

    Frequent mistakes during diagnostics and repairs

    Even experienced owners Nissan Sunny sometimes they make mistakes that lead to unnecessary expenses or worsening the problem. Here are the most common:

    • 🔍 Testing the relay only, ignoring the fuse - often the problem lies in a blown fuse 10A, which is responsible for both the relay and the pump.
    • 🔧 Relay replacement without checking ground - an oxidized ground contact on the body or gas tank can simulate a relay malfunction.
    • ⚡ Using relays from other models - even if it is externally identical, the response parameters may differ (for example, a relay from Nissan Primera not suitable for Sunny B14).
    • 💥 Supplying voltage to the pump without a fuse - this may burn the pump winding or cause a fire!

    Another common mistake is do not check the operation of the pump after replacing the relay. There are cases when the pump is already worn out and does not create the required pressure, and the owner sins on the electronics. Always check fuel rail pressure (norm for Sunny — 2.5-3.0 kg/cm²).

    ⚠️ Attention: If after replacing the relay the pump runs constantly (does not turn off after 2-3 seconds), this is a sign of a malfunction engine control module (ECM). It is impossible to operate the machine in this condition - this leads to overheating of the pump and its rapid breakdown.

    Analogs and prices for fuel pump relays for Nissan Sunny

    Original relay from Nissan is expensive (from 1,500 to 3,000 rubles depending on the region), but there are high-quality analogues that serve no worse. Here are the tested options:

    Manufacturer Article Price, rub. Notes
    Nissan (original) 25230-31U00 2500-3000 For B13/B14 with engines GA14/GA16
    Mitsuba MR585 800-1200 Japanese quality, complete analogue of the original
    Panasonic AGQ20004 600-900 Suitable for most Nissan 90s
    Bosch 0 332 209 150 500-700 Universal, but check compatibility by contacts

    When purchasing an analogue, pay attention to:

    • 🔌 Contact location - it must match the original (85, 86, 30, 87).
    • 📊 Rated current - no less 30A (usually indicated on the relay body).
    • 🔧 Mounting type - some relays have latches that are not suitable for the unit Sunny.

    If you buy a used relay, be sure to check it with a multimeter - burnt contacts inside are not always visible from the outside.

    FAQ: Frequently asked questions about the fuel pump relay Nissan Sunny

    Is it possible to drive with a faulty fuel pump relay?

    No, it's dangerous! If the relay does not turn on the pump, the engine will stall at any time. If the relay is “stuck” and the pump runs constantly, this leads to overheating and the risk of fire. In both cases, the car cannot be operated.

    Why does the pump still not work after replacing the relay?

    There are several reasons:

    • Burnt out fuel pump fuse (check 10A fuse in the block).
    • Oxidized contacts in the pump connector (the connector needs to be cleaned or replaced).
    • Defective the fuel pump itself (check it by applying voltage directly).
    • Problems with immobilizer (on models with SR20DE).
    Which fuse is responsible for the fuel pump in Sunny B14?

    In the majority Sunny B14 this is the fuse 10A with markings Fuel Pump. It is located in the main fuse box in the passenger compartment (next to the relay). On some versions it may be designated as EFI.

    Is it possible to temporarily close the relay to get to the service station?

    Yes, but this last resort! To do this:

    1. Remove the relay from the block.
    2. Jumper the contacts 30 And 87 a piece of wire (the pump will run continuously).
    3. Start the car and drive no more than 10-15 minutes — long-term operation of the pump without control will lead to its breakdown.
    ⚠️ Attention: This method disables the pump overheat protection! Don't use it regularly.
    Where to buy an original relay for Nissan Sunny?

    Original relays can be found:

    • At official dealerships Nissan (expensive, but quality guaranteed).
    • On Avito or Drom.ru (search by article number 25230-31U00, check the seller).
    • In Japanese spare parts stores (for example, JapanParts, Amayama).
    • On AliExpress (there is a risk of running into a fake, but there are trusted sellers with reviews).

    Before purchasing, compare the photo of the relay with your original - sometimes relays that look similar have different pinouts.