Mazda Cx-5: High Fuel Pressure Issues Explained

The Mazda CX-5 is a popular vehicle, but some owners have experienced issues with the high-pressure fuel pump. This component is responsible for delivering fuel from the tank to the fuel injectors, and problems with the pump can cause a range of issues, from reduced engine power to an inability to start the car. The pump is equipped with a fuel pressure sensor, and error codes P0192 and P0473 indicate issues with this sensor. Diagnosis and replacement of the high-pressure fuel pump can be expensive, and some owners choose to attempt this themselves, but it is important to take precautions to avoid the risk of fire when working with the fuel system.

Fuel pump replacement cost

The fuel pump in a Mazda CX-5 is located inside the fuel tank and has a small electric motor to ensure that pressurised gasoline flows to the engine to power the vehicle. The fuel passes through a filter, either inside the fuel tank or externally in the fuel flow line.

The fuel pump's main responsibility is to deliver gas from the fuel tank to the fuel injectors. The pump must deliver the right amount of fuel and at a high enough pressure to keep the engine running smoothly in all conditions. A failing fuel pump will not create enough pressure in the fuel system, possibly causing a loss of engine power or preventing the car from starting.

The average cost for a Mazda CX-5 Fuel Pump Replacement is between $611 and $970, but can vary from car to car. The cost of parts is typically around $323 to $815, while labor costs are estimated to be between $329 and $155. The price of the replacement also depends on your location and whether you choose to go to a dealer or an independent service centre. Dealers tend to use manufacturer-recommended parts, whereas independents may use non-official or aftermarket parts, which can result in a lower price.

High Fuel Pressure

A high-pressure fuel pump in a Mazda CX-5 can be replaced by a mechanic or the owner themselves. The crankshaft must be rotated approximately 90 degrees from TDC of cylinder No.1, and the pump must be inserted into the rear housing. The pump should be pressed in until the O-ring cannot be seen, and then bolts should be tightened to the specified torque.

Symptoms of a Bad Fuel Pump

• Car won't start or unexpectedly stalls and won't restart
• Check engine light is on
• Whirring noise from the fuel tank
• Engine "chokes" or struggles to maintain speed
• Noises, backfires, and a sputtering engine
• Hesitation at start or take-off
• Overheating engine

Fuel pump removal/installation

Fuel Pump Control Module Removal/Installation

• Disconnect the negative battery cable.
• Tip the rear seat (LH).
• Disconnect the clip connected to the trunk board.
• Disconnect the fuel pump control module connector.
• Remove the fuel pump control module.
• Install in the reverse order of removal.

Fuel Pump Unit Removal/Installation

• Complete the "BEFORE SERVICE PRECAUTION".
• Using the following procedure: Because the fuel surface is higher than the fuel pump unit installation surface, if the set plate is removed, it may result in fuel leakage. If the fuel gauge level indicates 1/2 or more, refer to the fuel draining procedure and drain 20 liters of fuel.
• Fuel gauge indicates 1/2 or more.
• Fuel gauge indicates less than 1/2.
• Disconnect the negative battery cable.
• Remove the rear seat cushion.
• Set the rear seat aside as shown in the figure.
• Partially peel back the floor mat as shown in the figure.
• Remove the service hole cover.
• Set the pressure control valve out of the way (U.S.A. and CANADA).
• Remove in the order indicated in the table.
• Fuel pump unit connector.
• Quick-release connector.
• Install in the reverse order of removal.
• Complete the "AFTER SERVICE PRECAUTION".

High-Pressure Fuel Pump Removal/Installation

• Complete the "BEFORE SERVICE PRECAUTION".
• Disconnect the negative battery cable.
• Remove the plug hole plate.
• Remove the air cleaner and air hose as a single unit.
• Disconnect the harness clip as shown in the figure.
• Disconnect the hoses as shown in the figure.
• Disconnect the following parts connectors: Purge solenoid valve and high-pressure fuel pump.
• Remove the purge solenoid valve and catch tank and purge solenoid valve bracket as a single unit.
• Remove in the order indicated in the table.
• Install in the reverse order of removal.
• Complete the "AFTER SERVICE PRECAUTION".
• Complete the "Fuel Leakage Inspection After High-Pressure Fuel Pump Installation".

Fuel pump issues diagnosis

Fuel pump issues can be dangerous and cause serious issues with your vehicle's performance and drivability. Here is a guide to help diagnose fuel pump issues:

Warning Signs of a Faulty Fuel Pump

• Your vehicle won't start or struggles to start.
• The engine sputters, stalls, or dies while driving, especially under stress (e.g., towing a heavy load or driving uphill).
• The engine surges while driving, resulting in speed spikes and drops without any input from the driver.
• You hear a loud, whining noise coming from the fuel tank, indicating a problem with the normal low hum of the pump.
• Lower fuel efficiency and poor fuel mileage, caused by damaged components letting excess fuel into the engine.
• Intermittent power loss, especially when the fuel level is low or the vehicle is parked facing uphill.

Diagnosis and Repair

• Check for error codes: Many modern vehicles have diagnostic systems that can provide error codes, such as the P0192 code for fuel rail pressure sensor issues in some Mazda CX-5 models. These codes can provide valuable information about potential issues.
• Inspect the fuel pump and related components: Look for any signs of damage, leaks, or wear. Refer to the vehicle's service manual for specific instructions and safety precautions, as working with fuel systems can be dangerous.
• Test the fuel pump: You can test the fuel pump by measuring the fuel pressure with a gauge plumbed into the fuel delivery system. This will help determine if the pump is functioning correctly and providing the correct fuel pressure.
• Replace the fuel pump if necessary: If the fuel pump is faulty, follow the manufacturer's instructions or seek professional assistance for replacement. Fuel pump replacement can be complex, especially in high-pressure fuel systems, and requires careful handling of flammable liquids and components under high pressure.
• Perform regular maintenance: Regular fuel system maintenance, including inspecting and replacing fuel filters and lines, can help prevent fuel pump issues and extend its lifespan.

Mazda CX-5 High-Pressure Fuel Pump Issues

Some owners of the Mazda CX-5 have reported issues with the high-pressure fuel pump (HPFP), which can lead to rough running and engine performance issues. Diagnosis and replacement of the HPFP in the Mazda CX-5 may require specific procedures, such as manually positioning the engine at a certain angle, and should be approached with caution.

Fuel pump problems and driving

Fuel pump problems can cause a range of issues while driving, from engine stuttering and stumbling to complete engine failure. Here are some common problems caused by a faulty fuel pump:

Engine Stuttering and Stumbling

An early sign of a failing fuel pump is a stuttering or stumbling engine. This can be intermittent and may go away as quickly as it appears. However, it can be a sign that the fuel pump is not supplying enough fuel to the engine, leading to these momentary losses in power.

Excessive Whining Noise

A fuel pump in a modern fuel-injected car should not be audible. If you hear a loud, excessive whining noise coming from your fuel tank, it could indicate that the electric motor in the pump is heating up and failing.

Engine Won't Take Throttle

As a fuel pump approaches the end of its life, it may not be able to supply enough fuel when demand is high, such as when accelerating from a stoplight or merging onto a freeway. This will cause the engine to stutter or stumble when you try to increase the throttle.

Engine Cuts Off for No Reason

If your fuel pump is failing, it may not be able to keep the engine running, especially when there is no load. This can lead to the engine cutting off for no apparent reason, and you may find yourself having to wait for the pump to cool down before restarting the engine.

Engine Won't Start or Starts and Shuts Off

Eventually, a failing fuel pump will not be able to create enough pressure to start the engine or keep it running. This is the most severe consequence of a faulty fuel pump and will require immediate attention.

High Fuel Pressure

While high fuel pressure itself may not directly impact the driving experience, it can lead to other issues such as fuel leaks and damage to fuel system components. It is important to address high fuel pressure to prevent further problems and ensure the safe operation of your vehicle.

Mazda CX-5 Fuel Pump Issues

Now, let's focus on the Mazda CX-5. Some owners of the 2016 and 2017 Mazda CX-5 have reported issues with the high-pressure fuel pump (HPFP). The symptoms include rough running, engine misfires, and trouble codes related to low fuel rail pressure. In some cases, the HPFP has been diagnosed as faulty and required replacement.

It is important to note that working on fuel systems can be dangerous due to the flammable nature of fuel. Always refer to the service manual and take the necessary precautions when performing any repairs or maintenance on your vehicle's fuel system.

Fuel pump maintenance

Weekly Visual Inspections

Conduct routine visual inspections at least once a week to identify any signs of wear or damage. Check for leaks on pumps, filters, hoses, nozzles, joints and fittings. Detecting problems early can prevent them from escalating into bigger issues and potential breakdowns.

Cleaning

Keep your pumps clean to preserve their functionality and maintain hygiene. Fuel pumps are touched by many people, so routinely cleaning them with a degreaser and gentle cleanser will help prevent the spread of germs. Avoid using harsh solutions, as ammonia-based cleansers can damage screens and other vital components.

Spill Management

There will inevitably be spills near your fuel pumps, and while these fluids can leave stains, it’s important to remove them promptly. Start by soaking up excess fuel with spillage absorbent granules and then use a pressure washer to remove stubborn stains.

Underground Tank Checks

Underground tanks with overfill alarms should be regularly inspected to ensure they are functioning correctly. These alarms help identify leaks, helping you mitigate potential hazards and avoid costly repairs.

Proactive Problem-Solving

Stay ahead of potential issues by scheduling your maintenance appropriately. Depending on the frequency of use, you may need to conduct weekly operational checks and monthly inspections. Addressing any issues promptly ensures the smooth operation of your fleet or vehicle and reduces the risk of downtime.

Specific to Mazda CX-5 High-Pressure Fuel Pumps

If you are the owner of a Mazda CX-5 and are experiencing issues with your high-pressure fuel pump, it is recommended that you refer to the service manual for detailed instructions on removal and installation. Some key points to note are:

• Fuel is a highly flammable liquid, so always complete the "Fuel Line Safety Procedure" and refer to the "BEFORE SERVICE PRECAUTION" section in the manual.
• Before draining fuel, discharge static electricity by touching the vehicle body to prevent fires or explosions.
• Do not disassemble the high-pressure fuel pump or damage the sealing surface/lock part of the fuel pipe.
• When removing/installing the high-pressure fuel pipe, record the number of times in the service records. Replace the pipe after the 5th removal/installation.
• Always clean the quick-release connector joint area before disconnecting/connecting to avoid damage to the fuel pipe and connector.
• Refer to the manual for detailed instructions on the removal and installation process, torque specifications, and post-installation checks.

For more complex issues, it is recommended to consult a skilled engineer or a mechanic.

Frequently asked questions