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Land Rover LR4 High Pressure Fuel Pump Diagnosing - Diagnosis and How To Test

Testing and diagnosing the high pressure fuel pump on land Rover LR4 vehicles using Autologic's DrivePRO

In this video, how to test and diagnose the high pressure fuel pump in Land Rover LR4 models is shown. Pump pressure can be used to diagnose a weak or failing pump. The pressure reading are easily displayed using Autologic's DrivePRO

Begin by identifying the vehicle you are working on

Select Automatic Detection

Confirm vehicle information is correct. Select Ok

Select Drive

Select Powertrain Control module (PCM)

Select the vehicle’s engine. In this example, 3.0L Supercharged V6 is selected

Select Faults (DTC)

Clear any stored fault codes. In this example, there are none

Select Back

Select Dynamic Data

Select Emissions Control

Select Fueling

Begin by confirming your sensor voltage

Beginning with the Low Range Sensor, sensor voltage is at 3.1 volts. Normally voltage should be between 1.3 – 3.1 volts. If the voltage were to read 4 - 5 volts or above, it would indicate a shorted sensor

Select Next

High Range Sensor is at 1.0 volts. Normally voltage should be between 1.0 – 3.1 volts. If the voltage were to read 4 - 5 volts or above, it would indicate a shorted sensor

Select Back to return to previous page

Fuel pressure reading can be found next to Fuel Pump Control B (Low Pressure) – Desired

When testing, begin with the key on and the engine off

Let’s start with Fuel Pump Control B (Low Pressure) – Desired

The current reading of 729 Kilopascals indicates a normal sensor value

Next we’ll look at Fuel Rail Pressure, and Fuel Rail pressure (Desired)

Fuel Rail Pressure is actual Fuel Rail Pressure and will vary, but usually the value will be between 2 and 3,000 kPa

Next, start the engine

Fuel Rail Pressure (Desired) will usually be between 5 and 6,000 kPa

Fuel Rail Pressure will quickly raise to match Desired, then both will stabilize to around 3,000 kPa

Fuel Pump Control B (Low Pressure) – Desired reading will remain at 729 Kilopascals while at high idle

Once engine idle stabilizes, the vehicle fuel pressure drops to 549 kPa

Next, raise and hold engine RPM at 3,000

Fuel Rail Pressure Desired and Actual should be around 4800 KPa