Transmission not shifting, overdrive button on dash doesn’t work

ANSWER : It seems like the defrost of the vehicle has an issue. There are several possibilities that could cause this. The control unit for the climate control system could be malfunctioning. The fuse for the rear defrost could be blown due to some unknown reason. The windshield itself could be damaged and lost connection somehow. I would recommend having a qualified professional who is proficcient in electrical diagnosis inspect your vehicle with a wiring diagram. This will help to determine where the fault in the defrost system is located. Once the issue is found, I would recommend having the issue resolved as soon as possible to prevent any safety issues that could result from lack of clear vision through the rear window.

ANSWER : As unfortunate as it is, your vehicle would be considered flood damaged. Diagnosing electrical problems in a flood damaged vehicle is nearly impossible. This would take many hours or even days to determine which wiring harnesses and circuits have been affected. Then nearly all of the wiring under the dash would likely require replacement as well as many sensors and switches. On a BMW vehicle, the amount of wires and switches are likely more than that of a lower end vehicle. Due to the inefficiency in cost, you would likely be able to purchase another BMW like yours for less than what it would cost to fix your car. Many insurance companies would consider this type of damage to total out the vehicle unfortuantely.

ANSWER : Hello, thanks for writing in. I’d be happy to offer my insight. It sounds like your car has an electrical problem. I would start by checking the signal going to the transmission from the computer. It may not have the proper voltage going to it. It may have a blown fuse or an ignition switch issue. If there is power going to it then it may actually be an issue with the computer itself. If you plan on having this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose this.

ANSWER : Hi there. Sure would appear a lot is going on electrically all at once. This could be, a problem in the PDC (power distribution center). The PDC is typically located under the hood and contains numerous fuses and relays. I don’t believe any one fuse will resolve all of the electrical issues. There is a possibility, it is not a power supply issue. It may be, the result of a poor electrical ground common to the inoperative components. Proper circuit testing should be performed. This would confirm the cause of multiple electrical failures. I recommend having your vehicle’s electrical problems be diagnosed and repaired by a certified technician, such as one from YourMechanic.

ANSWER : It is very possible that you could have some internal transmission damage. I would recommend enlisting in the assistance of a qualified transmission professional to inspect your transmission for internal faults. I must warn that this could be a pricy inspection as it may involve the removal and disassembly of the transmission. However, this is a sure fire way to determine if any internal damage has occured. The good news is that if any damage has occured, it can easily be resolved at that time since the transmissoin has already been disassembled.

ANSWER : if the engine speed is increasing and the vehicle does not move, the transmission is slipping. The first thing to do would be to let the engine idle and warm up to operating temperature and then check the transmission fluid level while the engine is running and the gear selector is in park. If the fluid is at the proper level and the transmission is malfunctioning there may be an internal failure. If the fluid level is too low from a leak, this may cause the transmission to slip as well. Consider hring an experienced technician like one from YourMechanic who can come out for a closer look and offer a more personal diagnosis of your transmission concerns.

ANSWER : Hi there. The dashboard lights are burned out in the dash and the dimmer switch could be worn causing the lights to be weak. The gauges that seldom fail to work is most likely a loose wire in the dash panel. The fuel gauge that is not going to E when shutting off the car has a damaged rheostat within the sending unit. The sending unit is in the fuel tank attached to the fuel pump. If you need further assistance with your gauges not working, then seek out a professional, such as one from Your Mechanic, to help you.

ANSWER : The problem could be that the internal transmission pump is weak, or the transmission clutch seals are leaking. It sounds like the transmission will need an overhaul.

I recommend having a transmission mechanic test the pressures and diagnose the problems to verify whether you need an overhaul with a new torque convertor.