Question about 1999 BMW 323 Series

2 Answers

P1477, Leakage Diagnostic Pump Reed Switch Did Not Open (BMW)

Posted by on

  • memenito Nov 15, 2010

    P1477, Leakage Diagnostic Pump Reed Switch Did Not

    bmw 323i yeard 2000


2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 662 Answers

There is a fault with you're fuel leak diagnostic pump. There is either a leak in your fuel lines or the pump itself is bad, or even your gas cap isn't making a proper seal. Running the car without solving this problem will have no affect on the car, however, if there is a fuel leak you might notice a loss in fuel economy. The pump itself should be located next to the carbon cannister. This pump pressurizes the fuel system to check for leaks. If the reed switch did not open, it would mean that the pump is still trying to pressurize the fuel. Have all your fuel lines checked out, along with your injectors. Also, you might want to change your fuel filter and check to see if your fuel pump is producing adequate pressure. If all else fails, replace the leakage diagnostic pump.

Posted on Nov 15, 2010

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Master
  • 6,826 Answers

Sounds like it has something to do with either the fuel system, more specifically in the evaporative fuel portion of the car.

A reed switch definition follows from Wikipedia:

The reed switch is an electrical switch operated by an applied magnetic field. It was invented at Bell Telephone Laboratories in 1936 by W. B. Ellwood.

Some people have changed the charcoal canister on their BMWs with this Malfunction Code, but that did not fix the problem.

Some people have changed the air filter and that didn't fix the problem.

Good luck on this repair.

Posted on Nov 12, 2010

1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Hi I have a 2008 Bmw 328i and the code p1447 came on what should I do ??

code p 1447 refers to diagnostic module tank leakage (DM-TL) pump too high during switching
the code is manufacturer specific so at this point , go to a service dealer and ask what that all means
if you don't get sense there find an accredited service center with experience on BMW cars and get it explained

Mar 27, 2017 | BMW Cars & Trucks

1 Answer

Code p1443

without knowing your make or model:

  • p1443
    Evaporative Emission Control System Control Valve
  • audi
    EGR Valve Position Sensor Signal Too Low
  • bmw
    Leakage Diagnostic Pump Control Circuit Signal High
  • ford
    EVAP Control System Purge Control Solenoid or Purge Control Valve Fault
  • hyundi
    EVAP System Tank Cap Missing
  • infinity
    Evaporative Emission Control System Control Valve
  • lexus
    Secondary Air Injection Vacuum Switching Valve Circuit Malfunction Bank 2
  • mazda
    Evaporative Emission Control System Large leak detected
  • mitsubishi
    EVAP Purge Control Valve 2 Circuit Malfunction
  • nissan
    Evaporative Emission Control System Control Valve
  • suburu
    Evaporative Emission Control System Vent Control Function Problem
  • suzuki
    EVAP Purge Control Valve Malfunction- Stuck Open
  • toyota
    Secondary Air Injection Vacuum Switching Valve Circuit Malfunction Bank 2
  • volkswagon
    EGR Valve Position Sensor Signal Too Low
  • Dec 07, 2013 | Cars & Trucks

    1 Answer

    I have a bmw 528i with diagnostic module tank leakage?

    Where is the module located in a 2009 BMW 528ixdrive

    Feb 07, 2013 | 2008 BMW 528i

    1 Answer

    I have 2007 BMW 335I that has been sitting in my garage for a month and started very little. the last time I started it the low coolant level light came on. Itis not leaking anywhere. What type of coolant...

    Hi Robert, No it is not normal for the coolant level to drop at any time. The BMW has a system which must be bled to free it of all air. The bleed screw is situated on the radiator and has a screw driver slot. Open the bleed screw and replace the coolant with the recommended coolant and then finish topping up with water until all bubbles have cleared from the system. Observe the level and if it drops again have a pressure test carried out on the system as if the level drops again, there must be a leakage. Likely places are hoses, and the water pump. If it is the water pump, the leakage may only be evident during engine operation, unless the leakage is severe in which case you will notice coolant dripping. Regards John

    Sep 15, 2012 | 2007 BMW 335i Sedan

    1 Answer

    2004 BMW 325i I have a code p1447 do you know were to fix?

    Fault codes do not have a single reason for being set, there are multiple reasons. here is the info you need to know about this code.
    P1447 - Evaporative Emission Control System Purge Flow Monitor
    Possible causes- EVAP canister purge volume control solenoid valve stuck closed
    - EVAP control system pressure sensor and the circuit
    - Loose, disconnected or improper connection of rubber tube
    - Blocked rubber tube
    - Cracked EVAP canister
    - EVAP canister purge volume control solenoid valve circuit
    - Closed throttle position switch
    - Blocked purge port
    - Closed throttle position switch

    Jun 13, 2012 | Cars & Trucks

    1 Answer

    P1477 reed switch not open- changed gas cap last week 2000 328ci

    Im going throught this problem also P1477 code on my E46/99 bmw 328i, also dont forget to check all the vacume lines, it is very common on this car that the hoses they use go rotten very quick, along with the intake tubes or elbows, i found massive holes on my mine also many vacume lines damaged, i still have the 1477 code, but ive seen various post were people swapped the fuel breather valve, i checked all the canister tours the rear of the vehicle, they all seemed fine , no broken lines, everything is tight but the fuel breather valve its only between 80 to 100$, compare to the 350$ canister... go figure, and its fixed quite a few cars, so ill give it try, wipe the codes, and hope it doesnt come back, good luck....

    Jun 13, 2011 | 2000 BMW 3 Series

    1 Answer

    P1441 code on2001 740il

    2001 bmw 740iL with code p1441 is the leakage diagnostic pump, you will need to check the connection to the pump and also test the evap system for any leaks, you may have a leak in the system, may be a loose gas cap or a line leaking, this system is for the fuel vapors, there are lines that run from the fuel tank to engine and is filtered into a canister and theres valves and leakage pump in lines, a smoke machine would be needed along with a scan tool to check valves and get readings from can check the gas cap and look around for broken lines. good day

    Apr 11, 2011 | BMW X7 Series Cars & Trucks

    2 Answers

    Code P1477

    Code P1477 means: EVAP LDP Circuit Malfunction. (It may just be a faulty gas cap)

    Nov 16, 2010 | 2002 Mercury Sable

    1 Answer

    Code P1494

    DTC P1494 - Leak Detection Pump Switch or Mechanical Fault

    The causes are possibly an open or shorted switch sense circuit, a pump switch failure, or an open "fused ignition switch" output. First off, a model year 2001 is will still covered under the emissions warranty. That's federal law. So you should not have had to pay a penny for that repair since the Leak Detection Pump is an emission control device.

    As is the Charcoal Canister. If that is bad there should be no charge for repair or replacement. I hope you saved the receipts because I think they owe you a bunch of money. If they give you an argument about it, call Chrysler and they will take care of it.

    Now, are you ready to learn more about the Leak Detection Pump then you will ever need to know? Good! Here it is!

    Leak Detection Pump (LDP) Operation And Diagnosis:

    This article describes the theory of operation for the leak detection system. In addition, information is provided for each of the Diagnostic Trouble Codes (DTC's) as follows:

    * P0442-Evap Leak Monitor 0.040" Leak Detected
    * P0455-Evap Leak Monitor Large Leak Detected
    * P0456-Evap Leak Monitor 0.020" Leak Detected
    * P1486-Evap Leak Monitor Pinched Hose Found
    * P1494-Leak Detection Pump SW Or Mechanical Fault
    * P1495-Leak Detection Pump Solenoid Circuit

    The evaporative emission system is designed to prevent the escape of fuel vapors from the fuel system. Leaks in the system, even small ones, can allow fuel vapors to escape into the atmosphere.

    Government regulations (remember I said that?) require on-board testing to make sure that the evaporative (EVAP) system is functioning properly. The leak detection system tests for EVAP system leaks and blockage. It also performs self-diagnostics.

    During self-diagnostics, the Powertrain Control Module (PCM) first checks the Leak Detection Pump (LDP) for electrical and mechanical faults. If the first checks pass, the PCM then uses the LDP to seal the vent valve and pump air into the system to pressurize it.

    If a leak is present, the PCM will continue pumping the LDP to replace the air that leaks out. The PCM determines the size of the leak based on how fast/long it must pump the LDP as it tries to maintain pressure in the system.

    EVAP Leak Detection System Components:
    Service Port: Used with special tools like the Miller Evaporative Emissions Leak Detector (EELD) to test for leaks in the system.

    EVAP Purge Solenoid: The PCM uses the EVAP purge solenoid to control purging of excess fuel vapors stored in the EVAP canister. It remains closed during leak testing to prevent loss of pressure.

    EVAP Canister The EVAP canister stores fuel vapors from the fuel tank for purging. EVAP Purge Orifice: Limits purge volume.

    EVAP System Air Filter: Provides air to the LDP for pressurizing the system. It filters out dirt while allowing a vent to atmosphere for the EVAP system.

    Leak Detection Pump (LDP) Components:
    The main purpose of the LDP is to pressurize the fuel system for leak checking. It closes the EVAP system vent to atmospheric pressure so the system can be pressurized for leak testing. The diaphragm is powered by engine vacuum. It pumps air into the EVAP system to develop a pressure of about 7.5' H20(1/4) psi. A reed switch in the LDP allows the PCM to monitor the position of the LDP diaphragm. The PCM uses the reed switch input to monitor how fast the LDP is pumping air into the EVAP system. This allows detection of leaks and blockage.

    The LDP assembly consists of several parts. The solenoid is controlled by the PCM, and it connects the upper pump cavity to either engine vacuum or atmospheric pressure. A vent valve closes the EVAP system to atmosphere, sealing the system during leak testing. The pump section of the LDP consists of a diaphragm that moves up and down to bring air in through the air filter and inlet check valve, and pump it out through an outlet check valve into the EVAP system.

    The diaphragm is pulled up by engine vacuum, and pushed down by spring pressure, as the LDP solenoid turns on and off. The LDP also has a magnetic reed switch to signal diaphragm position to the PCM. When the diaphragm is down, the switch is closed, which sends a 12 V (system voltage) signal to the PCM. When the diaphragm is up, the switch is open, and there is no voltage sent to the PCM. This allows the PCM to monitor LDP pumping action as it turns the LDP solenoid on and off.

    LDP At Rest (Not Powered):
    When the LDP is at rest (no electrical/vacuum) the diaphragm is allowed to drop down if the internal (EVAP system) pressure is not greater than the return spring. The LDP solenoid blocks the engine vacuum port and opens the atmospheric pressure port connected through the EVAP system air filter. The vent valve is held open by the diaphragm. This allows the canister to see atmospheric pressure.

    Diaphragm Upward Movement:
    When the PCM energizes the LDP solenoid, the solenoid blocks the atmospheric port leading through the EVAP air filter and at the same time opens the engine vacuum port to the pump cavity above the diaphragm. The diaphragm moves upward when vacuum above the diaphragm exceeds spring force. This upward movement closes the vent valve. It also causes low pressure below the diaphragm, unseating the inlet check valve and allowing air in from the EVAP air filter. When the diaphragm completes its upward movement, the LDP reed switch turns from closed to open.

    Diaphragm Downward Movement:
    based on reed switch input, the PCM de-energizes the LDP solenoid, causing it to block the vacuum port, and open the atmospheric port. This connects the upper pump cavity to atmosphere through the EVAP air filter. The spring is now able to push the diaphragm down. The downward movement of the diaphragm closes the inlet check valve and opens the outlet check valve pumping air into the evaporative system. The LDP reed switch turns from open to closed, allowing the PGM to monitor LDP pumping (diaphragm up/down) activity. During the pumping mode, the diaphragm will not move down far enough to open the vent valve.

    The pumping cycle is repeated as the solenoid is turned on and off. When the evaporative system begins to pressurize, the pressure on the bottom of the diaphragm will begin to oppose the spring pressure, slowing the pumping action. The PCM watches the time from when the solenoid is de-energized, until the diaphragm drops down far enough for the reed switch to change from opened to closed. If the reed switch changes too quickly, a leak may be indicated. The longer it takes the reed switch to change state, the tighter the evaporative system is sealed. If the system pressurizes too quickly, a restriction somewhere in the EVAP system may be indicated.

    Pumping Action:
    During portions of this test, the PCM uses the reed switch to monitor diaphragm movement. The solenoid is only turned on by the PCM after the reed switch changes from open to closed, indicating that the diaphragm has moved down. At other times during the test, the PCM will rapidly cycle the LDP solenoid on and off to quickly pressurize the system. During rapid cycling, the diaphragm will not move enough to change the reed switch state. In the state of rapid cycling, the PCM will use a fixed time interval to cycle the solenoid.

    The Charcoal Canister

    EVAP/Purge Solenoid:
    The duty cycle EVAP canister purge solenoid (DCP) regulates the rate of vapor flow from the EVAP canister to the intake manifold. The Powertrain Control Module (PCM) operates the solenoid.

    During the cold start warm-up period and the hot start time delay, the PCM does not energize the solenoid. When de-energized, no vapors are purged. The PCM de-energizes the solenoid during open loop operation.

    The engine enters closed loop operation after it reaches a specified temperature and the time delay ends. During closed loop operation, the PCM cycles (energizes and de-energizes) the solenoid 5 or 10 times per second , depending upon operating conditions. The PCM varies the vapor flow rate by changing solenoid pulse width. Pulse width is the amount of time that the solenoid is energized. The PCM adjusts solenoid pulse width based on engine operating condition.

    Vapor Canister:
    A maintenance free, EVAP canister is used on all vehicles. The EVAP canister is filled with granules of an activated carbon mixture. Fuel vapors entering the EVAP canister are absorbed by the charcoal granules.

    Fuel tank pressure vents into the EVAP canister. Fuel vapors are temporarily held in the canister until they can be drawn into the intake manifold. The duty cycle EVAP canister purge solenoid allows the EVAP canister to be purged at predetermined times and at certain engine operating conditions.

    Hope helps (remember rated and comment this).

    Jun 17, 2010 | 2001 Jeep Grand Cherokee

    2 Answers

    P1476 code

    Leakage Diagnostic Pump Reed Switch Did Not Open

    May 19, 2008 | 2004 Mini Cooper

    Not finding what you are looking for?
    1999 BMW 323 Series Logo

    Related Topics:

    1,333 people viewed this question

    Ask a Question

    Usually answered in minutes!

    Top BMW Experts

    Frankie B

    Level 2 Expert

    65 Answers

    Fred Sops

    Level 2 Expert

    272 Answers


    Level 2 Expert

    254 Answers

    Are you a BMW Expert? Answer questions, earn points and help others

    Answer questions

    Manuals & User Guides