1990 Toyota Pickup Fuel Pump Relay Location: The Complete Guide to Finding and Fixing It

If your 1990 Toyota pickup cranks but won't start, and you don't hear the fuel pump hum for two seconds when you turn the key to the ON position, the problem is almost certainly the fuel pump relay — or what Toyota calls the Circuit Opening Relay (COR). The fuel pump relay on a 1990 Toyota pickup is located behind the passenger side kick panel, near the ECU, above the glove box area. Removing the glove box and the right side kick panel gives you access to this black relay, which is held in by a single 10mm bolt. This guide walks you through exactly where to find it, how to test it, and how to replace it, so you can get your truck running again.

What Is the Fuel Pump Relay on a 1990 Toyota Pickup?

Toyota doesn't call it a "fuel pump relay" on your 1990 pickup. Instead, it's called the Circuit Opening Relay (COR). This relay controls power to the electric fuel pump. When you turn the key to the START position, the relay closes and sends power to the pump. Once the engine starts and you release the key, the relay stays closed because the airflow meter (AFM) sends a signal telling the relay the engine is running.

The relay has two separate coils inside:

  • Start coil: Activated by the ignition switch in the START position
  • Run coil: Activated by the air flow meter when the engine is sucking air

This setup is a safety feature. If you get into an accident and the engine stalls, the fuel pump automatically shuts off because the AFM stops sending a signal.

Exact 1990 Toyota Pickup Fuel Pump Relay Location

The Circuit Opening Relay on a 1990 Toyota pickup is located behind the passenger side kick panel, above the ECU (engine control unit). Here is the step-by-step process to find it:

Step 1: Remove the passenger side kick panel. This is the plastic trim panel on the passenger side footwell. It pops off with a few clips or screws.

Step 2: Remove the glove box. Open the glove box, squeeze the sides inward, and let it drop down. Some models require removing a few screws at the top of the glove box opening.

Step 3: Look above the ECU. The ECU is a silver or black box mounted vertically on the passenger side firewall. Above it, tucked up toward the dashboard, is the Circuit Opening Relay. It is a small black relay, usually with a metal bracket attached, and is secured by a single 10mm bolt.

Step 4: Locate the relay. On some trucks, the relay is also mounted just behind the right side of the glove box, near the blower motor housing. The wires going to the relay are typically Black/White, White/Black, Green/Yellow, Blue, and White/Red.

How to Test the Circuit Opening Relay

Before you buy a new relay, test the old one. Here is what you need to do:

Check for the fuel pump prime. Turn the key to the ON position (not START). You should hear the fuel pump hum for about 2 seconds. If you don't hear it, the relay may be bad.

Jump the diagnostic connector. On the 1990 Toyota pickup, there is a diagnostic connector under the hood. Locate the FP (Fuel Pump) and B+ (Battery Positive) terminals. Use a short piece of wire to jump these two terminals. Then turn the key to ON. If the fuel pump runs, the relay is likely bad or the wiring to the relay is faulty.

Test the relay resistance. Use a multimeter to measure resistance between the relay terminals. According to the factory service manual for the 1988-1995 era, the resistance specifications are:

  • STA to E1: 17-25 ohms
  • +B to Fc: 88-132 ohms
  • +B to Fp: Infinity (no continuity)

If the relay does not meet these specs, replace it.

Test the airflow meter circuit. The fuel pump relay is controlled by the AFM. On the air flow meter, check the brown wire. It should show continuity to ground. The green/yellow wire goes to the Circuit Opening Relay. When the AFM contacts close, the relay coil grounds and the fuel pump runs. If the AFM is bad, the relay won't activate.

Common Symptoms of a Bad Fuel Pump Relay

Here are the signs that your Circuit Opening Relay is failing:

  1. Engine cranks but won't start. This is the most common symptom. The engine turns over but never fires up because the fuel pump isn't getting power.
  2. No fuel pump prime sound. Turn the key to ON. You should hear a hum from the fuel tank for 2 seconds. If you don't, the relay is suspect.
  3. Engine starts then dies immediately. If the relay works in the START position but fails in the RUN position, the engine will start and then stall.
  4. Intermittent stalling. A failing relay may let the engine run for a while, then cut power to the fuel pump, causing the truck to stall unexpectedly.
  5. Fuel pump only works when jumped. If you jump the FP and B+ terminals at the diagnostic port and the pump runs, but it won't run normally, the relay or its control circuit is the issue.

What to Do If the Relay Tests Good

If you have tested the Circuit Opening Relay and it is working properly, the problem is likely elsewhere in the fuel system. Here are the next things to check:

Check the EFI main relay. The EFI main relay is located under the hood, in the fuse/relay block on the driver's side firewall. This relay powers the ECU and the Circuit Opening Relay. If the main relay is bad, the fuel pump won't get power.

Check the EFI fuse. The 15-amp EFI fuse is under the hood in the main fuse box. If this fuse is blown, the fuel pump relay won't get power.

Check the airflow meter. The air flow meter sends the signal to keep the relay closed in the RUN position. If the AFM is faulty, the relay will deactivate and the engine will stall.

Check the wiring harness. Look for broken, corroded, or melted wires between the relay and the fuel pump, especially in the area behind the passenger kick panel and along the frame rail leading to the fuel tank.

Check the fuel pump itself. If the pump is dead, jumping the diagnostic port won't make it run. Test for power at the fuel pump connector. If you have power and ground, the pump is bad.

How to Replace the Circuit Opening Relay

Replacing the relay is a straightforward job. Here is how to do it:

  1. Disconnect the negative battery cable.
  2. Remove the passenger side kick panel and glove box.
  3. Locate the Circuit Opening Relay above the ECU.
  4. Remove the single 10mm bolt holding the relay bracket.
  5. Unplug the relay from the wiring harness.
  6. Plug in the new relay.
  7. Reinstall the bolt and bracket.
  8. Reinstall the glove box and kick panel.
  9. Reconnect the battery.
  10. Test by turning the key to ON and listening for the fuel pump prime.

The OEM part number for the Circuit Opening Relay on a 1990 Toyota pickup is 85910-35010, also known as Denso part number 056700-8654.

Recommended Replacement: KEMSO Fuel Pump

If you find that your fuel pump itself is the problem — not the relay — you need a reliable replacement. The fuel pump in your 1990 Toyota pickup is located inside the fuel tank and is responsible for delivering fuel to the engine at the correct pressure. Over time, the pump wears out, the strainer clogs, or the internal motor fails.

KEMSO offers high-performance fuel pumps that are direct OEM replacements for your 1990 Toyota pickup. These pumps are built to meet or exceed factory specifications, ensuring your truck gets the fuel flow it needs to start and run smoothly. Every KEMSO fuel pump comes with a lifetime warranty, so you only buy it once. If you need a fuel pump that is reliable, durable, and backed by a company that stands behind its products, KEMSO is the right choice.

Visit the KEMSO website to find the correct fuel pump for your 1990 Toyota pickup: https://www.kemsoracing.com/

Frequently Asked Questions

Q: Is the fuel pump relay the same as the circuit opening relay?
A: Yes. On your 1990 Toyota pickup, Toyota calls it the Circuit Opening Relay, but it functions as the fuel pump relay.

Q: Where is the fuel pump relay on a 1990 Toyota pickup 22RE?
A: It is located behind the passenger side kick panel, above the ECU, near the glove box.

Q: Can I use a standard Bosch relay to replace the Circuit Opening Relay?
A: For early model pickups (1975-1978), a Bosch style 5-pin relay works as a replacement. For 1990 models, it is best to use the correct Toyota or Denso relay to avoid wiring issues.

Q: Why does my truck start with fuel in the carb but not run?
A: If you can start the engine by pouring fuel directly into the carburetor (on carbureted models) or the intake, but it won't stay running, the fuel pump is not delivering fuel. Check the relay, the pump, and the wiring.

Q: How do I test the fuel pump relay without a multimeter?
A: Jump the FP and B+ terminals at the diagnostic connector. If the pump runs, the relay or its control circuit is the problem.

Final Thoughts

The 1990 Toyota pickup fuel pump relay location is not complicated once you know where to look. Behind the passenger kick panel, above the ECU, you will find a small black relay called the Circuit Opening Relay. This is the component that controls power to the fuel pump. If your truck cranks but won't start, start here. Test the relay, check the EFI main relay and fuse, and inspect the wiring. If the pump itself is the culprit, replace it with a KEMSO fuel pump for a reliable, long-lasting solution backed by a lifetime warranty.

For more information and to find the right fuel pump for your 1990 Toyota pickup, visit https://www.kemsoracing.com/


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