[NBH1]

E90 - 325i - N52 - 2006

I’ve had the car for over 4 years, no issues except for the battery dying on me if I leave the lights on for too long.

Decided to finally change the battery last Sunday, car wouldn’t start anymore. It cranks forever but won’t start. I didn’t have an INPA cable yet so just took a guess that it might be a coincidental fuel pump failure so I replaced the fuel pump a few days ago and same problem.

Got myself an INPA cable yesterday and read the codes and I got

1. 2CF9 - Throttle Valve potentiometer 1
2. 2CFA - Throttle Valve Potentiometer 2
3. 2D1D - gas pedal module , pedal sensor 1 , power supply
4. 2D09 - throttle valve

Some thoughts, my old battery was 680CCA and the new one is 640CCA, could that be too low for the car not giving it enough power to start ?

I’ve read live data using INPA and this battery drops to 6-7 volts when trying to start. However, I recharged my old battery and retried it and it’s the same problem cranks but won’t start. Also tried jump starting hooked up to another car and same problem, crank no start.

Using INPA I activated the fuel pump and it works through the Engine module, however when I try to access the EKPS module I get the “no response from the control unit” error.

[ctuna]

Did you try actually measuring the voltage at critical points .
with a voltmeter.
Like the Engine bay and the Cabin fuse box?
You are suppose to match the amp hours as closely as possible when
replacing the battery and also the battery type . (lead acid vs AGM)
did you try clearing the error codes and seeing which ones come back?
If the battery drops 6 volts during a start that is not good.

[NBH1]

Originally Posted by ctuna

Did you try actually measuring the voltage at critical points .
with a voltmeter.
Like the Engine bay and the Cabin fuse box?

No I didn’t think of doing that yet, I measured it using INPA tools live data, is physically measuring the critical points more accurate ?

I will try that tomorrow thanks for suggestion

[3PedalJake]

I have the same car, and had the same issue after a battery change a few months ago. My issue was a blown output on the EKPS module. I would try to activate the fuel pump with inpa, if it doesn't run there's a good chance that's your problem. If you do a visual inspection of the module there will be clear evidence of a short.
Edit: I see you tried activating the module. Also that you're getting no response from the module. I'd bet $ it's fried. You can get one $20, $30 on ebay.

[NBH1]

Originally Posted by 3PedalJake

I have the same car, and had the same issue after a battery change a few months ago. My issue was a blown output on the EKPS module. I would try to activate the fuel pump with inpa, if it doesn't run there's a good chance that's your problem. If you do a visual inspection of the module there will be clear evidence of a short.
Edit: I see you tried activating the module. Also that you're getting no response from the module. I'd bet $ it's fried. You can get one $20, $30 on ebay.

I am highly suspecting it’s this however, I can active the fuel pump directly using DME on INPA. However, I can’t communicate to EKPS module.

Could you active your fuel pump when your EKPS was fried ?

[3PedalJake]

Originally Posted by NBH1

I am highly suspecting it’s this however, I can active the fuel pump directly using DME on INPA. However, I can’t communicate to EKPS module.

Could you active your fuel pump when your EKPS was fried ?

I used Protools not inpa, but no I could not activate the pump. Also had the no communication error. On visual inspection the module was clearly damaged. This is a simple thing to check if you have folding rear seat. I didn't, and removing the seat back to get to the module was 9/10ths of the job.

[NBH1]

Originally Posted by 3PedalJake

I used Protools not inpa, but no I could not activate the pump. Also had the no communication error. On visual inspection the module was clearly damaged. This is a simple thing to check if you have folding rear seat. I didn't, and removing the seat back to get to the module was 9/10ths of the job.

Sounds like we have the same car, mines a non folding seat too so I’m for a treat haha.

Seems like it’s worth a check, I will try to give it an inspection tomorrow thanks for your advice.

[3PedalJake]

I'm still puzzled why it died right after a battery change when it was starting up fine until then, but then these bimmers are a mystery wrapped in an enigma sometimes.