This post is about my 08 BMW 535i power loss and got advice to use BMW scan tools. I.E ICOM, inpa, k+can to read and clear trouble code, then according to the code to fix the problem.
BWM specific model and year: 2008 535i
Symptom:
While driving on the interstate, casually, not speeding, the car lurched and threw a trans malfuntion light, then abs light, then very shortly after the idrive screen went blank, then overtemp light came on, then srs light. Then the dash gauges stopped working and the car began to loose power and eventually rolled to a stop. This all happened from start to finish in about 2 miles.
What I have done:
Turned igniton off, pulled the key and reinserted it attempting to start the car, nothing, completely dead. So I got someone to jump it off and tested the voltage at the battery and was showing 13 volts, as i suspected it was the alternator that had failed. Well, the car ran great, but had an error code,”high battery drain”. Made it home with no issues, parked the car overnight. The next day I went to go to work and the car was completely dead again.
So I get the car to my garage, install a new alternator after charging the battery and it starts right up, only now its telling me the oil level sensor has failed(which has never been an issue before) and the car is intermittently throwing the overtemp readout. This was in about 40 miles of driving, throwing the overtemp readout on and off about 5 times. This is also a new issue.
Advice from experienced technician:
Hopefully you won’t try to “reprogram the DME” before you’ve done the basic troubleshooting steps like pulling and then resetting the BMW-specific codes, registering the new battery, etc. Until you’ve done that, you’re shooting in the dark. If you want to troubleshoot this issue yourself you’ll need to either borrow or purchase the necessary BMW scanning tools. All you need is a smartphone app like BMWhat / Carly for BMW or Torque (not sure that latter will allow you to do battery registrations though) and a cheap $8 ELM327 Bluetooth adapter or better or get BMW inpa K+can cable.
DTC read out:
IBS fault-over maximum threshold, Coolant pump fault-no signal, Oil level sensor fault-over maximum threshold.
Then I tried to do but make no difference:
I was able to register the battery to the car and attempted to disconnect the IBS, but no joy. All problems still persist. I also attempted to test the coolant pump with a 50% and 95% run test, but made no difference to the coolant pump. It just ran at the same speed, with the ignition on, engine off. Sounded like it was barely running too. If I open a door or the trunk with the key not even in the car I can hear the pump running also.
More questions and answers:
Question 1:
once the car loses power everything goes haywire … As you know it throws just about every error in the book and the error codes get stored due to the loss of voltage . And they might not all be active .
When you pulled the codes did you clear them ? Then running the car did those 3 errors come back and are they active faults ?
Answer: Yes they were all active faults and immediately returned after clearing them.
Question 2:
Is the car starting ok ? Because the IBS and oil level sensor will cause a no start if they fail .
Also is the car over heating?
Answer: Ya car starts every time. It does throw the overheat message on the dash. First yellow, then red.
Question 3:
For peace of mind I would install a new water pump and thermostat and the lower hose and sensor . Are you still on the original water pump ?
Answer: I am, as far as I know, on the original pump. Car has 80k on it. Are you referring to the coolant temp sensor?
Question: 80,000 for sure change it , ya the temp sensor on the lower hose . You might as well swap it out with a new pump and thermostat.
