BMW E3. 0E3. 6 DME Motronic ECU Swap 3 Series 1. The Bosch Motronic Engine Management system is what controls the ignition, timing and emissions controls of the later model 3 series cars. As such, it can be considered the brain of the car. The ECU Electronic Control Unit will cause the engine to run poorly or to stop running altogether if it becomes damaged. NTAwWDM2OQ==/z/yYgAAOxydlFSsRyf/$_3.JPG?set_id=2' alt='Bmw Timing Tools Ebay' title='Bmw Timing Tools Ebay' />In this tech article, well talk a little about the DME, how to troubleshoot its problems, prevent damage to the unit, and repair or replace the unit. Read the Codes. First, if you are having problems with your car, you should check to see if the computer is giving out any fault codes. See the Pelican Technical Articles, Code Reading and OBD II Diagnostics for more details. If the code readers are having trouble connecting to the unit, then you need to look further. DME Relay. Many people I have spoken to have had problems with the relay that controls the DME computer itself. Its not uncommon for the main relay to have its contacts become corroded and fail to work 1. Even if the relay is intermittent, it might show up as the engine running rough, or stalling, or any other number of failures. I/147/54/8570.jpg' alt='Bmw Timing Tools Ebay' title='Bmw Timing Tools Ebay' />One of the first steps I would take is to identify this relay on E3. BMWs, its relay number two, the white one, next to the fuel pump. Try swapping it out with a known good one if you have one, or swap it with another one on the board like the one for the fog lamps. Try starting the car. If you see an improvement, then you might have found the problem. Start with the relay it is the easiest and cheapest item to replace. Early E3. 6 DME Compartment Flooding Problem. On E3. 6 BMWs manufactured prior to July of 1. DME computer. The water relief channels of the car are not beefy enough to withstand a significant influx of water onto the car, or the windshield. While perfectly adequate for anything that nature may throw at the car, the channels are woefully inadequate for a car wash. If too much water is used, or if the water channels are clogged with leaves or debris, the water will overflow and leak into the compartment where the DME is stored see the Pelican Technical Article on DME Chip Replacements for the location of the DME in the engine compartment. I have heard stories of owners who have opened this compartment, only to have a gallon of water or more come flowing out. Needless to say, having the main computer for the car submerged in water is not a good thing. How exactly does the water get into the box The DME compartment is located right next to the intake plenum cowl for the heating and air conditioning system. Find great deals on eBay for VW Timing Tool in Other Automotive Hand Tools. Shop with confidence. BMW 3 Series Forum BMW E21, E30, E36, E46, E90, E91, E92, E93, F30, F31, F34GT, F80 M3 forum. Auto Express Welcomes you to our Ebay store With many years of selling NEW quality parts, Well provide you with. Bmw Timing Tools Ebay' title='Bmw Timing Tools Ebay' />Details about for bmw x5 e53 3. E38. org is the source for sharing knowledge and information about enjoying, caring for, maintaining, repairing and owning the BMW 5series and 7series automobiles. This cowl is open to the enviroment, and thus will get rain water deposited into it. There are drains at the bottom designed to drain this rainwater. However, if the volume of water is too great, or the channels become clogged with leaves or other debris, this plenum will overflow directly into the DME compartment. If enough water fills this chamber, it may also leak into the passenger side foot well, although this often goes unnoticed, as the water will leak under the passenger floor mat. BMW has issued a Service Bulletin and a relatively inexpensive fix for the problem. The fix is to install a third drain and use an improved style of drainage hose. The BMW factory bulletin that describes this repair is 4. July 1. 99. 4. Begin by removing the plastic screen covering the plenum, the portion of the plenum that covers the firewall, and move the wiring harness out of the way on the left side of the engine compartment. Then remove the cylinder head valve cover you will need to do this to gain clearance for working see the Pelican Technical Article on Valve Cover Gasket Replacement. Cover the top of the engine with a drop cloth or plastic garbage bag to prevent anything from falling in. Now, pull back the insulation that is located against the rear firewall. Remove and throw away the right side plenum drain hose at this time Figure 1. Behind the firewall material, there is a circular area pre stamped in the firewall just above and to the right of the original drain location. You will be drilling out this hole and installing the new drain hose in this hole. BMW specifically recommends against using a hole saw here the metal shavings are too likely to contaminate either the engine or the plenum area. Instead, start with a. Then, use a 34 conduit punch and enlarge the hole to 2. File off the edges, paint with a small bit of primer, and then reinstall the firewall insulation. Drill a corresponding hole in the installation, and install your two new drain hoses part number 5. Thats the BMW fix described for this problem. Figure 2 shows the area where you need to drill yellow arrow, and also points to the oil drain hose green arrow that should be pulled out and replaced behind the cylinder head, which in this photo is covered by plastic. If you are not fortunate enough to have read this article before your DME got toasted, you may still have a chance to revive it. Open the DME compartment and remove the DME unit see the Pelican Technical Article on Chip Upgrades for more details. If your DME is covered and soaked with water, then you may be able to save it. Take the unit apart and expose the two circuit boards Figure 3. Although I have not used it myself, I have had several Pelican Parts customers tell me that spraying the board with WD 4. The board is already soaked in water at this point, what could it hurt Take the DME boards and place them in an oven set at about 1. This should help evaporate any remaining water that may have made it into the unit. Reassemble the unit, and plug it back into your car to see if the problem still exists. If it does, then you will probably have to replace the unit with another one see this topic later in this article. Cracked Solder Joints. Some DMEs stop working for reasons that dont seem obvious like being submerged in water. If you borrow a DME computer from a friend and your car works perfectly, then you have indeed isolated the problem to the DME circuit board. It is possible to sometimes inspect and repair these units. Serial Vs Parallel Dilution. The most common failure associated with old electronics units are cracked solder joints. Have you ever had a Walkman type stereo that had a broken head phone plug If you wiggled the plug one way, you could hear, but if you let go of the plug it would stop working This is a symptom of a cracked solder joint, and it can occur in your DME as well. If you take a close look at your board, you may be able to spot a cracked solder joint. Some broken joints are not able to be seen with the naked eye though. You have a good shot at repairing these joints by simply reflowing the solder at large solder connections that seem like they may be attached to components that give off heat. The heat causes the crack to enlarge and then may separate, causing an intermittent failure. The same thing can happen if the DME is rattling or exposed to excess vibration. To repair a cracked solder joint, simply get out your solder arm and reflow the solder Figure 4. In a unit that I am repairing, I usually like to reflow the solder on all the joints that are pretty large, and particularly the ones that look like they are attached to heat sinks. These are most likely to experience cracks and failures. DME Swapping. Finally, if youve tried all of the approaches outlined above, and your DME unit still doesnt work, then you will probably have to replace it.