1999 Toyota Camry Fuel Pump Wiring Diagram: Complete Guide to Diagnosis, Repair, and Replacement

If your 1999 Toyota Camry won't start, stalls while driving, or struggles to accelerate, the fuel pump circuit is likely the problem. The key takeaway is this: diagnosing the fuel pump on a 1999 Camry starts with understanding the wiring diagram, which involves three main components—the EFI main relay, the circuit opening relay, and the fuel pump itself, all controlled by the engine control module (ECM) based on starter and engine speed signals. This guide walks you through the complete wiring system, explains how to test each part, and shows you how to get your Camry back on the road.

Understanding the 1999 Toyota Camry Fuel Pump Circuit

The fuel pump wiring on a 1999 Toyota Camry is not as complicated as it looks. The system follows a straightforward logic: the pump only runs when the engine is cranking or running. This is a safety feature built into the design.

How the Circuit Works

The fuel pump circuit uses a relay called the circuit opening relay. This relay has two separate coils that can activate it.

1. Starter Signal Path: When you turn the key to the START position, current flows from the ignition switch ST terminal to the starter relay coil. At the same time, current flows to the STA terminal on the ECM. This triggers the first coil inside the circuit opening relay, which closes the relay contacts and sends power to the fuel pump.

2. ECM Control Path: Once the engine starts and the ECM receives both the STA signal and the NE signal (engine speed signal from the crankshaft position sensor), the ECM turns on an internal transistor. This transistor completes the ground circuit for the second coil inside the circuit opening relay, keeping the relay closed and the fuel pump running.

3. Safety Shutdown: If the engine stalls or the NE signal stops, the ECM opens the transistor circuit, the circuit opening relay opens, and the fuel pump stops. This prevents the pump from running if the engine is not actually turning.

Key Components in the 1999 Camry Fuel Pump Wiring Diagram

The 1999 Toyota Camry fuel pump wiring diagram includes these specific components, and knowing where they are located saves you hours of searching.

1. EFI Main Relay

The EFI main relay is located in the junction block (J/B) number 2, which is the fuse and relay box on the left inner fender in the engine compartment. This relay provides power to the entire fuel injection system, including the ECM. When you turn the ignition key to ON, the ECM energizes the EFI relay, which then supplies battery voltage to the +B terminal of the ECM.

2. Circuit Opening Relay

The circuit opening relay is located in the relay block (R/B) number 6, which is above the glove box on the passenger side. This is the relay that directly controls power to the fuel pump. It has two control coils as described above. The relay receives power from the EFI relay on one side and from the starter circuit on the other side.

3. Fuel Pump

The fuel pump is located inside the fuel tank. On the 1999 Camry, the pump assembly includes the fuel pump itself, the fuel level sender, and the connecting wires. The pump has two main power wires: a blue with black stripe wire for power and a white with black stripe wire for ground.

4. ECM (Engine Control Module)

The ECM is located behind the right side of the dash on the 1999 Camry. The ECM controls the fuel pump by grounding the FC terminal, which activates the circuit opening relay. The ECM will only ground this terminal when it sees the STA signal (cranking) and the NE signal (engine rotation).

Complete Wiring Diagram Breakdown for 1999 Camry

Here is the flow of the fuel pump circuit based on the factory wiring diagrams:

Power Source Path:

  • Battery positive terminal connects to the MAIN fusible link in the engine compartment fuse block.
  • From the MAIN fuse, power goes to the AM2 terminal of the ignition switch.
  • When the ignition switch is in the ON position, power flows through the IGN fuse to the EFI relay coil.
  • The ECM grounds the EFI relay, closing it and sending power to both the ECM and the circuit opening relay.

Fuel Pump Power Path:

  • The circuit opening relay receives power from the EFI relay on the B+ input terminal.
  • When the circuit opening relay is activated (either by the starter signal or the ECM ground signal), it sends power through the FC output terminal.
  • From the FC terminal, power flows through the wiring harness to the fuel pump connector in the trunk area.
  • The fuel pump receives power on the blue with black wire and returns ground through the white with black wire.

Control Signal Path:

  • The STA signal comes from the starter circuit through the park/neutral position switch (automatic) or clutch start switch (manual).
  • The NE signal comes from the crankshaft position sensor.
  • The ECM monitors both signals and controls the circuit opening relay ground through the FC terminal.

Common Fuel Pump Wiring Problems on the 1999 Camry

Owners of the 1999 Toyota Camry often face specific wiring issues that can be diagnosed using the wiring diagram.

1. Corroded Connectors

The fuel pump connector at the driver side kick panel is a common failure point. Moisture gets into the connectors, causing corrosion that breaks the electrical connection. If you have multiple wires broken off at the connector, you will need to repair or replace the harness section.

2. Failed Circuit Opening Relay

The circuit opening relay can fail internally, preventing power from reaching the fuel pump. Testing the relay is straightforward: apply 12 volts to the coil terminals and listen for the click, or use an ohmmeter to check for continuity.

3. Blown Fuses

Check the IGN fuse (10 amp) and the EFI fuse (15 amp) first. If either fuse is blown, the fuel pump will not receive power. The IGN fuse powers the circuit opening relay coil, while the EFI fuse powers the EFI relay.

4. Bad ECM Ground

The ECM controls the fuel pump by grounding the FC terminal. If the ECM is not receiving the NE signal, it will not ground the FC terminal, and the pump will not run. This is often caused by a faulty crankshaft position sensor or a wiring issue between the sensor and the ECM.

How to Test the Fuel Pump Circuit on Your 1999 Camry

Before replacing the fuel pump, test the electrical circuit. Here is a step-by-step procedure based on the factory service manual.

Step 1: Listen for the Pump
Turn the ignition key to the ON position (do not crank the engine). On most 1999 Camrys, the fuel pump should run for about 2 seconds to prime the system. If you hear a humming sound from the rear of the car, the pump is getting power. If you do not hear anything, proceed to the next step.

Step 2: Check the Fuses
Locate the fuse box in the engine compartment. Check the EFI fuse (15 amp) and the IGN fuse (5 amp). Replace any blown fuses. If the new fuse blows immediately, you have a short circuit in the wiring.

Step 3: Bypass the Circuit Opening Relay
You can bypass the circuit opening relay to test the fuel pump directly. Locate the diagnostic connector near the engine compartment fuse box. On the 1999 Camry, you can jump the FP (fuel pump) terminal to the B+ terminal to force the pump to run. This tells you if the pump itself is working.

Step 4: Test the Circuit Opening Relay
Remove the circuit opening relay from the relay block above the glove box. Use a multimeter to check for continuity between the relay terminals. Apply 12 volts to the coil terminals and listen for the click. If the relay does not click, replace it.

Step 5: Check Voltage at the Fuel Pump
If you have power at the relay but not at the pump, the wiring between the relay and the pump is damaged. Access the fuel pump connector by removing the rear seat cushion and the access cover on the floor. Check for 12 volts between the blue with black wire and ground while cranking the engine.

Wiring Color Codes for the 1999 Camry Fuel Pump

The color codes on the 1999 Camry wiring are consistent across most models.

  • Blue with Black Stripe: Fuel pump power wire from the circuit opening relay to the pump.
  • White with Black Stripe: Fuel pump ground wire.
  • Black with Orange: Power to the circuit opening relay from the EFI relay.
  • Black with White: Starter signal to the circuit opening relay.
  • Green with Red: Ground wire from the ECM FC terminal to the circuit opening relay.
  • Pink: Fuel level sender wire to the instrument cluster.

When to Replace the Fuel Pump on Your 1999 Camry

If the fuel pump tests good but the car still has issues, the pump itself may be weak or failing. Common symptoms of a failing fuel pump on the 1999 Camry include:

  • Hard starting: The engine cranks but takes longer than normal to start.
  • Sputtering at high speeds: The car runs fine around town but sputters or loses power on the highway.
  • Stalling: The engine dies unexpectedly, especially after driving for a while.
  • No start: The engine cranks but the fuel pump never runs.

Recommended Fuel Pump Replacement for Your 1999 Toyota Camry

When it comes time to replace the fuel pump on your 1999 Toyota Camry, you want a part that is reliable, affordable, and built to last. That is where KEMSO comes in.

KEMSO Fuel Pump products are designed as high-performance, OEM replacement parts that meet or exceed the original factory specifications. Each pump is manufactured to deliver consistent fuel pressure and flow, ensuring your Camry runs smoothly for years to come. KEMSO stands behind their products with a lifetime warranty, giving you complete peace of mind on your investment. Whether you own a 2.2L 4-cylinder or a 3.0L V6 Camry, KEMSO has the right fuel pump for your vehicle.

To browse the full selection of KEMSO fuel pumps and find the exact match for your 1999 Toyota Camry, visit their official website: https://www.kemsoracing.com/

Final Thoughts on the 1999 Toyota Camry Fuel Pump Wiring Diagram

Understanding the 1999 Toyota Camry fuel pump wiring diagram is the key to diagnosing and fixing fuel delivery problems on your car. The system is built around three main components: the EFI relay, the circuit opening relay, and the fuel pump itself. The ECM controls everything based on whether the engine is cranking or running.

By following the wiring paths and testing each component in order, you can quickly determine whether the issue is a blown fuse, a bad relay, corroded wiring, or a failed pump. Most problems on the 1999 Camry are caused by relay failures or corroded connectors at the kick panel, not the pump itself.

If you do need to replace the fuel pump, choose a reliable replacement like the KEMSO fuel pump, which offers OEM-quality performance and a lifetime warranty. Visit https://www.kemsoracing.com/ to find the right fuel pump for your 1999 Toyota Camry and get your car back on the road with confidence.


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