Replacing Fuel Pump In Volvo C70: Step-By-Step Guide

If your Volvo C70 is failing to start, it could be due to a faulty fuel pump. To access the fuel pump, you will need to drop the fuel tank as it is located underneath the structural support. Before attempting to replace the fuel pump, ensure that you have the necessary tools and safety equipment, and consider consulting a repair manual or seeking assistance from a professional if you are unsure about the process.

Locating the fuel pump

The fuel pump in modern Volvo automobiles, including the C70, is typically located inside the fuel tank. To access it, you will need to remove the rear seats or drop the fuel tank. Some Volvo models have an access panel under the rear seats or cargo compartment carpet, so check if your vehicle has one. If not, you may need to cut an access hole.

Before attempting any repairs or maintenance, it is essential to take safety precautions. Make sure to wear protective gear, including eye protection, gloves, and clothing that covers your body. If you are working with the electrical system, disconnect the battery before beginning any work. Always catch fluids in appropriate containers and properly dispose of any waste.

Now, to locate the fuel pump, start by identifying the fuel tank. The fuel pump is usually located on the right side (passenger side) of the fuel tank. Once you have found the fuel tank, look for the access panel, which may be under the rear seats or cargo compartment carpet. If you cannot find an access panel, you may need to remove the rear seats or drop the fuel tank to access the fuel pump.

It is worth noting that your car may have been serviced before, and the fasteners used may be different from the original ones. Be prepared with different-sized sockets and wrenches to remove any fasteners. Additionally, your vehicle may vary slightly from others of the same model, as designs can change over time. If something seems different or you cannot locate the fuel pump using the above instructions, consult a repair manual or seek advice from a Volvo mechanic.

Remember, working on your vehicle can be dangerous if you are not confident in your abilities. If you feel the task is beyond your skill level, it is best to seek professional help.

Removing the fuel tank

To remove the fuel tank in a Volvo C70, you will first need to locate the fuel pump. In some Volvo models, the fuel pump is located inside the fuel tank, on the right side (passenger side). However, in the case of the C70, the fuel pump is located under the fuel tank, which means that the tank will need to be dropped or removed to access it.

• Park your car on a level surface and engage the parking brake. Ensure that the engine is cool before starting work.
• Place a suitable container under the fuel tank to catch any spilled fuel.
• Locate the fuel lines and disconnect them from the tank. Be careful not to damage the lines and have a rag handy to catch any spilled fuel.
• Identify and disconnect the electrical connections to the fuel pump. You may need to remove any protective covers or panels to access the connectors.
• Locate the fuel tank straps or brackets and remove them. There may be multiple straps or brackets holding the tank in place, so ensure you remove all of them.
• Carefully lower the fuel tank. You may need an assistant to help with this step as the tank can be heavy.
• Once the tank is lowered, you can access the fuel pump for replacement.

It is important to note that working on a fuel system can be dangerous, so ensure you take the necessary safety precautions and have the appropriate tools and knowledge before attempting this job. Always refer to your vehicle's service manual for specific instructions and safety information.

Additionally, some Volvo C70 owners have reported that creating an access panel in the back seat may provide access to the fuel pump without needing to drop the fuel tank. However, this method may not work for all models, and it is essential to be cautious when modifying the vehicle's structure, especially in a convertible.

Checking the fuel pump relay

To check if the fuel pump relay is working, you can run a direct power feed to the pump to see if it is working. If it is, then the problem is likely to be the relay.

You can also try tapping the relay first, but a more telling method is to check the voltage at the block connector in the rear left cubby hole (assuming an estate, but the saloon should be in a similar location). Use an indicator lamp to do this. You should get voltage and pump noise briefly on the first key turn and again when turning the engine over. The pump prime won't go again unless you leave it off for around 10-20 seconds, and you can usually hear something click when the priming is able to go again. If there is no voltage, then it is not the pump, but it could be the crank sensor or the relay.

To check for the crank sensor, watch the rev counter for movement after it sees TDC. The ignition computer needs this for spark timing and sends the conditioned pulses onto the fuel computer, which then enables the pump relay as a safety mechanism.

You can also try bypassing the relay with a handheld connector, but don't use a constant connector like a crocodile clip until you have confirmed the problem.

Another method is to remove the relay, put the relay back in, and wiggle the contacts with a lollipop stick or a small finger. If the engine then starts, it's the relay.

If the in-tank pump has failed, the car will still run, but the main pump will be noisier as it is working harder.

To check the relay circuit, you can use a digital multimeter (DVOM). Connect the black lead of your DVOM to the battery negative, and use the other to backprobe the terminals.

If you have no voltage to the pump, you can check the relay function by removing the under-hood fuse panel cover and checking the fuel pump fuse. You can also jump out your fuel pump relay (to bypass it) for testing.

Testing the fuel pump

Before replacing the fuel pump in your Volvo C70, it's important to confirm that the pump is faulty. Here are the steps to test the fuel pump:

Step 1: Check Voltage with a Digital Volt Ohmmeter (DVOM)

• Use a DVOM to confirm if the fuel pump received the correct voltage when commanded on by the fuel pump relay.
• If the correct voltage is present but the pump does not activate, the pump is likely faulty.

Step 2: Access Terminals for Testing

• Use a wiring diagram to determine the correct terminals for testing.
• Access these terminals under the cargo compartment carpet, below the access panel.

Step 3: Electrical Testing

• Remove the storage compartment lid and slide out the carpet panel.
• Pull up and remove the side trim panel, repeating for both sides.
• Remove the storage lid fasteners and then remove the storage lid to expose the wiring harness junction.
• Working at the fuel pump access panel, remove the fasteners and then remove the access panel.
• Locate and disconnect the fuel pump electrical connector.

Step 4: Connect DVOM to Fuel Pump Terminals

• Connect the DVOM across the fuel pump terminals, which are the two large wires at the connector.
• Turn the key to the "ON" position.
• The DVOM should read battery volts (around 12 volts).
• If no voltage is found, check the relay, fuel pump fuse, and relay.

Step 5: Load Testing

• Connect the DVOM across the fuel pump electrical connector terminals and take a reading.
• It should read battery volts when the key is turned on.
• Connect an incandescent bulb-style test light to the battery ground.
• Touch the test light probe tip to the positive wire you are back-probing with the DVOM.
• Your reading should hold steady, and a maximum voltage drop of 0.5 volts is acceptable.

Step 6: Check Fuel Pump Fuse

Remove the under-hood fuse panel cover and check the fuel pump fuse.

Step 7: Locate and Check Fuel Pump Relay

• Working on the left side of the wiper cowl, loosen the Torx screws and remove the electrical compartment lid.
• Locate and remove the fuel pump relay.
• Check that the relay has power with the key in the run position.

Step 8: Check Relay Circuit with DVOM

• Connect the black lead of the DVOM to the battery negative terminal.
• Use the other lead to back-probe the relay terminals.
• Cross-reference your voltage readings with the wiring diagram.

Step 9: Activate Fuel Pump with Jumper Wire

• Remove the fuel pump relay.
• Connect a fused jumper wire between specific terminals (refer to a diagram for your specific vehicle).
• This will activate the fuel pump.
• Check for voltage at the fuel pump as before. Battery volts should be present.

If the above tests indicate a faulty fuel pump, you can proceed with replacing the fuel pump in your Volvo C70. Remember to take appropriate safety precautions when working on your vehicle and always refer to a qualified mechanic if you are unsure about any procedures.

Replacing the fuel pump

Step 1: Check the fuel level

Before beginning any work on your Volvo C70, it is important to check the fuel level. This will help you determine if there is an issue with the fuel pump and if it needs to be replaced.

Step 2: Confirm voltage

If you suspect that your fuel pump has failed, you can use a digital volt ohmmeter (DVOM) to confirm if the fuel pump is receiving the correct voltage when turned on by the fuel pump relay. If the correct voltage is present but the pump is not activating, it is likely faulty.

Step 3: Prepare tools and safety equipment

Gather the necessary tools, including a DVOM, test light, and jumper wires. It is also important to protect yourself by wearing eye protection, gloves, and other appropriate safety gear when working on your vehicle. Additionally, if you are working with the electrical system, be sure to disconnect the battery before beginning.

Step 4: Access the fuel pump

To access the fuel pump, you will need to remove the back seat of your Volvo C70. This may involve removing the seat backrest by locating and pressing a clip on the top middle of each seat. Once the backrest is removed, you may need to cut an access hole, as the fuel pump is located inside the fuel tank on the right side (passenger side).

Step 5: Remove and replace the fuel pump

Once you have accessed the fuel pump, you can remove it by disconnecting the electrical connector and fuel lines. Be sure to catch any fluids in appropriate containers and properly dispose of any fluid waste. Then, install the new fuel pump by connecting the electrical connector and fuel lines securely.

Step 6: Reassemble and test

After replacing the fuel pump, carefully reassemble all the components and parts that were removed. Once everything is back in place, start the engine and test the fuel pump to ensure it is functioning properly.

Please note that the process may vary slightly depending on the model year of your Volvo C70, and it is always recommended to refer to a repair manual or seek professional assistance if you are unsure about any steps.

Frequently asked questions