In this guide, we take a look at how to troubleshoot BMW EKPS module using an OBD-II diagnostic scanner. You will learn what EKPS module is, what systems it covers, and how to read/clear codes from EKPS module.
What is BMW EKPS module?
Electronic fuel pump control module (EKPS) control the power to your BMW fuel pump. EKPS control unit is not the same component as the fuel pump. The EKPS unit is usually installed in the trunk (side panel) or under the rear seat while the fuel pump is mounted on top of the fuel tank.
The engine management system sends the request for the fuel required at the moment to the EKP control module. The EKP control module converts this request into a corresponding engine speed for the fuel pump in the fuel tank. The EKP control module then activates the fuel pump according to the engine speed. TIS Document 16 02 03036
When replacing the EKPS module it is required the new EKPS module is programmed (coded) to the car. Many BMW owners have been able to successfully swap the EKPS module with a used unit without needing to program it as long as the used EKPS module is from a similar BMW model and engine.
List of possible symptoms you may notice if the EKPS module or one of its components fails.
- Warning message on iDrive screen
- Fuel supply low
- Fuel Pump Malfunction
- Engine Malfunction! Reduced Power!
- Engine cranks but will not start
- Fuel pump voltage too low
- The engine starts then shakes
- Hesitation under hard acceleration
- Engine misfire and sputtering
- BMW would not stay running
In some cases, the engine may start but shake then cut off. Waiting a few minutes will often allow you to restart the engine.
How to read / clear EKPS Fault Codes
If you are experiencing problems a good starting point is to read fault codes from the EKPS module. If any code is PRESENT it needs to be addressed. If codes are in STORED / PAST status, they can be erased.
What you will need
A diagnostic scanner that is capable of reading, clearing and performing bi-directional tests on BMW vehicles. You must verify that the scanner that you use supports your BMW model and year. Full system scanners that are known to work on BMW vehicles can range in price from $150 to $800 USD.
List of scanners that read and clear BMW EKPS fault codes.
Other OBD2 scanners allow you to read and clear BMW EKPS fault codes. To learn about other OBD2 scanners that work on BMWs check this article on Choosing the best OBD2 scanner for BMW.
- Plug in the OBD-II scanner into the diagnostic port under the dashboard.
- Turn on the ignition, don't start the engine.
- Turn on the scanner and select your BMW chassis. Next, Select Control Units menu.
- Select Drive then EKPS fuel pump control.
- Once you enter the EKPS module, you will be able to do the following.
- Read Codes from EKPS Module
- Clear Codes from EKPS Module
- Perform Adaptations, Activations, Tests
A defective EKPS control unit, bad fuel pumps or leaky injectors can demonstrate similar symptoms. Proper diagnostics can be a challenge even for experienced BMW technicians.
- EKPS Module - EKPS module can fail causing no start problem or cause issues under hard accleration. A software update can sometimes address certain EKPS module problems. If software update does not fix the problem, replacing the EKPS module may be necessary.
- Fuel Pumps - BMW cars have two fuel pumps. Low-pressure fuel pump (LPFP) and the high pressure fuel pump (HPFP). Either one can fail prevening your BMW from staring or causing low pressure error messages to come up. If you are experiencing problems where the car will run rough and the engine RPMs will not go past 2000, the problem could be one of the fuel pumps.
- Leaky injectors - One leaky fuel injector can cause the same symptoms and even trigger fault codes in the EKPS module. Perform fuel injector tests to enusre that a leaky injector is not the culprit.
This is a list of activations that you can perform via the EKPS module.
- Reset EKPS control unit
- Activate fuel pump
TIP! Your scanner must be able to perform bi-directional tests to carry out these adaptations and activate sensors or modules.
In the EKPS Module, you can display live data from various sensors that communicate with the EKPS module.
- Fuel pump actual speed Unit r/min
- Setpoint delivery quantity via CAN bus from engine Unit l/h
- Specified delivery rate, fuel pump Unit l/h
- Specified speed, fuel pump Unit r/min
- Current at fuel pump (A)
- The voltage at the fuel pump, terminal 15, terminal 30 (Volt)
There are hundreds of fault codes that can be saved in BMW EKPS module. Below are some examples of codes stored in BMW EKPS module.
- 481B01 EKPS control voltage too low
- 6292 EKPS - Control voltage to low
- 6291 6293 - Control Current too high
- 0029DC - Low pressure in the high pressure system
- 0029F3 - Fuel pressure sensor, electric (Could also be caused by a defective fuel pressure sensor. )
- 002B2C - High-pressure fuel system, fuel pressure
- 0029DC - High-pressure fuel, plausibility, cold start
- 29F2 - DME fuel high pressure system, fuel pressure.
- 29F1 - DME (gasoline engine control)Fuel pressure fuel, plausibility
- 2AAE - Fuel pump, Intermittent