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The starter motor activation voltage comes from CAS at terminal 50. The most common initial cause of a burned CAS module is a subpar engine ground cable. In order to determine whether there is activation voltage at the starter motor and, if not, to examine the CAS module.
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Immobilizer is the first of Comfort’s primary tasks.
The general procedure for starting the engine is as follows:
* The EWS data is read from the remote control’s data memory by a ring coil in the CAS control unit. The remote control is secured in position in the ignition lock if it is a genuine, functional key for the car.
The CAS then transmits the command (terminal R on) through the data buses following this locking. Numerous control systems are turned on as a result.
* The four outputs at CAS terminal 15 are activated. Through terminal 15-3, the relief relay for the ignition coils is turned on.
All of the control units connected to the PT-CAN data bus are enabled upon activation of the outputs terminal 15 WUP (wake-up).
The CAS determines whether the brake pedal is depressed and the gear selector lever is in the P or N position when the start-stop button is pressed. The engine is started if this circumstance is true:
* The CAS switches a positive (battery voltage) at the DME control unit across line terminal 50E, indicating that the engine is to be started.
* The CAS switches a positive (battery voltage) at the comfort start relay across terminal 50L. The starter motor has been activated.
* A random EWS code is transmitted to the DME control unit via the data line D-EWS.
* The engine control unit checks the calculated code to the random code sent over the air. The fuel injection and ignition are turned on if they line up.
Until the CAS control unit receives the signal (Engine running) from the engine control unit through the data channel, the starting motor continues to turn. The CAS terminals 50 are then turned off.
Terminals 50 are deactivated after a maximum of 20 seconds and the engine start is interrupted if the engine doesn’t start.
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Hello, I’m new to Ista. I’m attempting to determine why my automobile won’t start.
The automobile tried to start last night, but it wouldn’t turn over or make any noise on the second try. Every attempt yields the same results. I checked the battery’s voltage, which was 12.3 volts plus, and I had the battery inspected at a nearby auto shop. Despite being three years old, the battery passes tests well.
No. Testing the starter is the obvious next step. If everything is fine, the next step is to check Terminal 50 to see if CAS is truly applying 12 volts to the line to the solenoid. Perhaps checking the ground strap between the engine and chassis is your first reasonable step.
Is A0B4 the only trouble code that ISTA is reporting before we move any further? Please report all of them.
The starter has no sensors, therefore the only way to determine how well it is working is to see if CAS can detect the activation of Terminal 50. The code A0B4 is not very specific and can actually imply nothing more than that the engine won’t start despite your repeated attempts to start it. It may also indicate that your CAS is fried, which is a regular issue.
Simply unplug the solenoid’s single, 16-gauge wire (I believe it is white, but you can check ISTA to be sure), and you can test the starter with ease. Put 12 volts on that solenoid terminal using a jumper. Naturally, this tests the starter and solenoid, but the best course of action is to replace them together if one of them is defective.
If it does, the issue is most likely with CAS, though it might also be a connector or a wiring issue between CAS and the solenoid. You can find a burned component on the circuit board if you open the CAS. Unfortunately, a used CAS cannot just be picked up and plugged in. It will be necessary to “clone” the CAS, which you cannot do using ISTA or BMW standard tools. The relevant services can be found online if you require them. Look up “BMW CAS cloning.” In this thread, there are some seasoned users who are qualified to post.
gbalthrop
Anyone know if the terminal 50e reading of 0.0 volts using ISTA in the CAS module is normal? The others all share comparable values and are reliable. (Apart from terminal 15 wakeup (acc)
I’m not sure if you understood what I said. The CAS “Terminal” (consider relay output) that operates the starter solenoid is Terminal 50, also known as KL50. Unless the clutch and start button are simultaneously depressed, Terminal 50 ordinarily has “0” Volts and “0” Amps (AT in P & Brake Pressed). Due to the starter voltage drop, KL50 V should be 10.5V for the first one to two seconds the starter cranks.
On a BMW, what is Terminal 30?
For control systems that are in use when the driver is not present, use the Terminal 30 Fault. For instance, the automatic climate control module (ACCM), footwell module (FRM), instrument cluster, and trailer module (AHM) all fit this description (IHKA)
How can you start a BMW in terminal 15?
Regarding keyless ignition switches, I have a stupid query. I’ve seen that as a first step, you “change your ignition switch to R or terminal 15” in a number of manuals and how-to instruction pamphlets. Could someone kindly explain how a 2005 745i keyless ignition works? See, I warned you that was foolish, but I’m not really sure of the solution. Thanks
what instructions should be included in flyers? You intend to start the vehicle. Put the remote in your lap, depress the brake, and push the start/stop button while sitting in the car.
What does a BMW’s DME relay do?
When the ignition is turned on, the engine ECM receives battery power via the DME main relay, which serves as the principal power source for almost all engine management operations. Engine difficulties including hard starting and poor performance might be brought on by a broken DME relay. If it entirely fails, you can be left with an unstartable engine.
Does BMW require a unique battery?
Finding a great BMW battery is one of the most crucial factors to take into account if you want the best for your luxury vehicle. For the best performance on the road, you must purchase a BMW car battery that satisfies the strict criteria of the vehicle.
The 5, 6, and 7 Series BMW vehicles typically have very high features. These automobiles need a lot more energy than your typical car does, thus we strongly advise obtaining them strong batteries.
You must be aware of your vehicle’s needs before purchasing a BMW battery. An Absorbent Glass Matt (AGM) battery is strongly advised for modern BMW vehicles with start-stop technology since it can handle the increased energy demand. However, you can also utilize an Enhanced Flooded Battery (EFB) if you want to buy something for less money.
Just keep in mind that you should only replace the original AGM battery in your BMW vehicle with another AGM. Because these vehicles weren’t intended to be utilized with EFBs, downgrading will cause battery and engine problems with your BMW. On the other hand, if your BMW came with an EFB at the factory, switching to an AGM battery won’t cause any issues.
EFBs outlive ordinary batteries in terms of longevity. They were created specifically for entry-level start-stop vehicles, so they can easily handle the rigorous needs of the majority of modern automobiles.
However, you should always choose an AGM battery if you want to spend more money on a more potent BMW battery. Although these batteries are made for start-stop vehicles, they are also compatible with other energy-consuming vehicles.
In comparison to conventional batteries, they offer a three times longer cycle life and may be utilized in all kinds of weather. Additionally, an AGM battery is necessary if you frequently use the car’s accessories.
BMWs with typical power requirements can be powered by standard automobile batteries. Therefore, if your car doesn’t have high-end gadgets or a start-stop system, you don’t require a special BMW car battery.
What occurs if a BMW battery is not programmed?
The car will overcharge or undercharge you if you don’t register it with it. When you install a new battery, the automobile will overcharge it since older batteries receive more charge than fresh ones, which causes your battery to die sooner.
Can a BMW be jump-started safely?
DO NOT let any roadside assistance agency install a new battery in your BMW, and DO NOT jump start the vehicle. It might cost more than any other battery or jump start you’ve ever purchased.
Can you safely jump-start a BMW?
NEVER jump start the vehicle, and NEVER allow any towing company to replace the battery in your BMW. The battery or jump start you get can be the most expensive of your life.
- Seven-Series E65/E66 chassis from 2002 and after
- 6-Series E63/E64 chassis from 2003 and after
- 5-Series E60/E61 chassis from 2004 and after
- X5 E53 chassis with N62 engine, 2005 and newer.
- 3-Series E90/E91/E92/E93 chassis from 2006 and after
- X5 E70 chassis from 2007 and after
- X6 E71 chassis for years 2008 and beyond
Does my BMW require reprogramming after a battery change?
Let’s first focus on what BMW battery registration genuinely is before delving into the procedure. Battery registration, to put it simply, is the process of notifying your car that a brand-new battery has been installed. Importantly, it must be done every time you replace the battery in your BMW, model year 2002 or later.
The car adapts the amount of energy required to recharge to operate at peak levels as your battery ages and gradually loses its ability to charge. The battery needs more charging the older it is. By registering your battery, you can inform your engine control module (also referred to as DME — Digital Motor Electronics) that a new one has been installed. As a result, the vehicle will reset the old battery statistics and won’t attempt to overcharge the new battery under the assumption that the old one is still in place.
In addition to registering, you must also code your BMW computer. No matter how different or similar your new battery is from your previous one in terms of specifications, it will still be necessary each time you change it.
How can I restart my BMW now that the battery is new?
Here are the instructions so that you can see how crucial the BMW computer reset is after reading the preceding explanation.
- Once the lights and radio are turned on, first switch the ignition key of the BMW automobile to the accessory position. This must be completed prior to starting the car. Then, hold down the “Trip” button on the instrument panel for a few seconds until the red light appears.
- Once more, press and hold the “Trip” button until Reset appears.
- Press the same button a third time after that. The BMW computer will quickly reset now.
BMW automobile battery replacement and computer reset are both inexpensive procedures. The sooner you complete this, the easier it will be for you to operate your BMW vehicle. Despite all of these facts, this surgery should not be taken lightly. There are auto repair shops with qualified experts who adhere to the manufacturer’s warranty guidelines. To receive a safe and secure service, consult these businesses.