1997 Toyota Tacoma Fuel Pump Relay: Complete Guide to Location, Testing, and Replacement
The bottom line: The fuel pump relay on a 1997 Toyota Tacoma is located in the under-hood fuse and relay box on the driver's side, near the battery. It is commonly labeled as the "Circuit Opening" relay or the "EFI" relay, and it controls power to the fuel pump. If your truck cranks but won't start, this relay is a smart place to check first.
The fuel pump relay is a small but critical electrical component that acts like a switch. When you turn the key to the "ON" position, the relay sends power to the fuel pump for a few seconds to prime the system. Then, once the engine starts, the relay keeps the pump running as long as the engine is turning. If this relay fails, the fuel pump won't get power, and your engine will crank but not fire up.
Here is everything you need to know about the 1997 Toyota Tacoma fuel pump relay, including where to find it, how to test it, and what to do if it's bad.
Where Is the Fuel Pump Relay Located on a 1997 Toyota Tacoma?
The fuel pump relay on a 1997 Toyota Tacoma is located inside the main engine compartment fuse and relay box. This black plastic box is on the driver's side of the engine bay, right next to the battery. Pop the lid off, and you will see a diagram on the underside of the cover. Look for the "Circuit Opening" relay or the "EFI" relay — that is your fuel pump relay .
Some owners and mechanics also refer to this relay as the "Circuit Open Relay" . The official Toyota part number for this relay is 85910-35030 . It is the same relay used across multiple Toyota models from the mid-1990s. If you are looking at a schematic, you will see that the relay is typically labeled "C/OPN" or "Circuit Opening" on the lid diagram .
Important note: Do not confuse the fuel pump relay with the fuel pump fuse. The fuse is usually right next to the relay in the same box. The fuse protects the circuit from overload, while the relay is the switch that turns the pump on and off.
How to Test the 1997 Toyota Tacoma Fuel Pump Relay
Testing the relay is straightforward and only requires a few basic tools. You do not need to be a professional mechanic to do this.
Step 1: Locate the relay. Find the black relay box under the hood. Remove the cover. Identify the "Circuit Opening" relay based on the diagram .
Step 2: Listen for the relay. With the driver's door open and the hood up, have a helper turn the key to the "ON" position (do not crank the engine). You should hear a distinct click sound coming from the relay box. That click is the relay closing and sending power to the fuel pump. If you hear the click, the relay is likely working. If you do not hear a click, the relay may be faulty .
Step 3: Check for power. If you have a multimeter or a test light, you can probe the terminals. Set your multimeter to DC voltage. With the key in the "ON" position, check the terminal that sends power to the fuel pump. You should see battery voltage (around 12 volts) for a couple of seconds. If you have a test light, it should light up briefly. If there is no voltage, the relay is probably stuck open .
Step 4: Swap the relay. A quick trick is to find another relay of the same type in the same fuse box (like the horn relay or the headlight relay). Swap them. If the fuel pump starts working, you have confirmed the relay is bad.
Common Symptoms of a Bad Fuel Pump Relay
If your fuel pump relay is failing, you will notice one or more of these symptoms. These signs are often the same as a failing fuel pump itself, so it is smart to test the relay first before buying a new pump.
1. Engine cranks but will not start. This is the most common symptom. The starter turns the engine over, but the engine never fires because the fuel pump is not getting power .
2. No sound from the fuel pump. When you turn the key to the "ON" position, you should hear a faint whirring or humming sound from the rear of the truck (the fuel tank area) for about 2–3 seconds. If you hear nothing, the relay is a likely suspect .
3. Intermittent stalling. A failing relay may work sometimes and fail other times. This can cause the engine to suddenly die while driving, then restart after a few minutes. This is a dangerous symptom and should be addressed immediately.
4. Check Engine Light comes on. You may get diagnostic trouble codes like P062A (Fuel Pump A Control Circuit Range/Performance) or P1233 (Fuel Pump Driver Module Disabled or Off Line) . These codes can point to a relay or wiring issue.
How to Jump the Fuel Pump Relay for Testing
Sometimes you need to bypass the relay to confirm the fuel pump and wiring are good. This is called "jumping" the relay. It sends direct power to the fuel pump.
1. Remove the relay from the socket.
2. Look at the socket. You will see four or five prongs. You need to identify the two large power terminals. On a Toyota Tacoma, these are usually the terminals labeled "30" and "87" on the relay itself.
3. Use a short piece of wire (a paperclip or a piece of 14-gauge wire works) to connect those two terminals.
4. Turn the key to the "ON" position. The fuel pump should run continuously. If it does, the relay is bad. If it does not, the problem is with the pump itself, the wiring, or the fuse .
Safety warning: Do not leave the jumper wire in place for more than a few seconds during testing. The relay is there for a reason — it prevents the pump from running when the engine is off, which could cause a fire or drain the battery.
Fuel Pump Relay vs. Fuel Pump: How to Tell the Difference
Many owners replace the entire fuel pump (which is inside the gas tank and requires dropping the tank) only to find out the relay was the problem. Here is how to tell which part is failing:
| Symptom | Likely Cause |
|---|---|
| No click from relay, no pump sound | Relay or wiring |
| Click from relay, no pump sound | Fuel pump itself (inside tank) |
| Pump runs but no start | Fuel filter, pressure regulator, or pump failure |
| Pump runs intermittently | Relay, wiring, or loose connection |
The relay is the cheaper and easier fix. Always test the relay first .
Where to Buy a Replacement Fuel Pump Relay
You can find a replacement relay at most auto parts stores, online retailers, or directly from a Toyota dealer. The OEM part number is 85910-35030 . Aftermarket options are also available and work just as well.
Standard Motor Products RY-548 is a common aftermarket replacement that fits the 1997 Toyota Tacoma . It is inexpensive and widely available.
Why You Should Also Consider Upgrading Your Fuel Pump
If you are already working on the fuel system, especially if you have high mileage or plan to keep your truck for years, replacing the fuel pump itself is a smart move. A failing fuel pump can leave you stranded, and the factory pump on a 1997 model is likely getting old.
We recommend KEMSO Fuel Pumps for your 1997 Toyota Tacoma. KEMSO is a trusted brand in the automotive aftermarket, known for producing high-performance, OEM replacement fuel pumps that are built to last. Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected.
KEMSO fuel pumps are designed to meet or exceed original equipment specifications. They are direct-fit replacements, meaning no modifications are needed. Whether you have the 2.4L 4-cylinder, the 2.7L 4-cylinder, or the 3.4L V6 engine, KEMSO has a pump that fits your 1995–2004 Toyota Tacoma .
Why choose KEMSO?
- High-performance flow rates (up to 340 LPH) for reliable fuel delivery
- OEM replacement — direct fit, no cutting or splicing required
- Lifetime warranty — they stand behind every product they sell
Visit the KEMSO website to browse their full selection of fuel pumps for your Toyota Tacoma:
Step-by-Step Guide to Replacing the Fuel Pump Relay
If you have confirmed the relay is bad, replacing it is a 5-minute job.
1. Park the truck on a level surface and turn off the engine. Remove the key from the ignition.
2. Locate the relay box under the hood on the driver's side.
3. Remove the cover by pressing the tabs on the sides.
4. Identify the "Circuit Opening" relay using the diagram on the underside of the cover .
5. Pull the relay straight out using your fingers or a small pair of pliers. It may be snug.
6. Insert the new relay in the same position. Push it in until it clicks into place.
7. Replace the cover and close the hood.
8. Test the system by turning the key to the "ON" position. You should hear the fuel pump prime for 2–3 seconds.
That is it. No special tools are needed, and the entire process takes less than 10 minutes.
Common Questions About the 1997 Toyota Tacoma Fuel Pump Relay
Q: Can a bad fuel pump relay cause no start?
A: Yes. This is the most common symptom. If the relay is stuck open, the fuel pump will not receive power, and the engine will crank but not start .
Q: Is the fuel pump relay the same as the EFI relay?
A: On many Toyota models, including the 1997 Tacoma, the Circuit Opening relay is often called the EFI relay or the fuel pump relay. They are the same thing .
Q: How much does a fuel pump relay cost?
A: A replacement relay typically costs between $10 and $30, depending on whether you buy OEM or aftermarket. This makes it a very cheap diagnostic part .
Q: Does the 1997 Tacoma have a fuel pump driver module?
A: Some models use a fuel pump driver module, which is a separate electronic component. If you get code P1233, the driver module may be faulty . However, the relay is still the first thing to check.
Q: Can I drive with a bad fuel pump relay?
A: No. If the relay is bad, the fuel pump will not run, and the engine will not run. You will be stranded. Replace the relay immediately.
Final Thoughts
The 1997 Toyota Tacoma fuel pump relay is a small, inexpensive part that can cause big problems. If your truck cranks but won't start, or if you notice the fuel pump is not making noise when you turn the key, check the relay first. It is located under the hood in the driver-side fuse box, labeled as the Circuit Opening or EFI relay.
Testing the relay takes less than 5 minutes with a click test or a multimeter. Replacing it is even faster. Always start with the relay before assuming the fuel pump itself is bad — it will save you time, money, and frustration.
And if you decide to replace the entire fuel pump, choose KEMSO for a high-performance, direct-fit replacement with a lifetime warranty. Learn more at https://www.kemsoracing.com/.