[Dolach]

Hi all,

My e90 328xi 2007 wont start , was starting perfecty fine one day before. This is what I’ve checked so far and still working:
- Battery
- Starter
- CAS relay
- Battery safety terminal
- intelligent battery sensor (IBS)
- DME relays and fuses
- Clutch position sensor
- Start fuse and start button
- No fault codes so not crank/cam position sensor

When I push the start button I think I can hear the fuel pump going but, starter doesn’t move at all. Running out of ideas now. I can say the temperature was quite high before the car stopped working . Dis anyone experience something similar?

[nsjames]

starter doesn't move at all means that the engine never actually turns over?

Bar the engine over by hand to make sure it's free, since you stated it was overheated.

what exactly led to this situation and what exactly does the car do when you push the button?

[Dolach]

When I push the button, I can hear electronic from the back of the car for 1-2 seconds(fuel pump I assume). Nothing from the front, not even the starter solenoid. Then the 4x4 warning, brake assist warning and couple of other pop up in the cluster when the car fails to start. I bought a multimeter to check if there’s current delivered from the CAS module to the solenoid when I push the button. Did not have the chance to check yet.

[Donutz]

Engine ground strap. On my N54 it's on the driver's side near the engine mount. I had a no start situation; replaced the starter only to find a broken ground strap. During my no start I didn't have any codes, until I changed the starter.

A quick test is to use one side of a jumper cable. Ground the cable to the chassis and then the engine; try to start the car while the temporary grand is in place.

[Dolach]

Just tried it, engine ground strap is fine.

[nsjames]

I would tend to agree with that.

the dashboard lighting up reeks of power supply issues.

get out a multimeter. start checking for voltage drops.

[Dolach]

Ok so all the voltage is good , did some tests and ehen i push the start button, CAS module is not sending power to the starter, all the relays and fuses in between are good. So whether the CAS module is bad or s squirrel chewed the wire. Plus i get the A0B4 code” engine start error starter operation

[Dolach]

Here is a picture of the status of the CAS when I try to start the car:

View post on imgur.com

the red arrows means there's no voltage at this location.

[nsjames]

that cas code is telling you that the cas is attempting to trigger the starter.

when I had that error the starter was faulty.

replaced the starter and the car worked.

you said you tested it, how?

[Dolach]

Yeah so I removed and connected directly to the battery because I didn’t have a multimeter to check the voltage If it had any voltage when trying to start the car. The solenoid and starter motor were working. But in the meantime I ordered a multimeter, put the starter back to its place, hooked the multimeter and tried to start the car. There is indeed voltage at the starter.. Ithink you are right, it was the starter all along

[gbalthrop]

Originally Posted by Dolach

Ok so all the voltage is good,[WHAT voltage readings did you take WHERE, and under WHAT conditions (Ignition ON, START button pressed with foot on Brake/Clutch, etc.)?] did some tests and ehen i push the start button, CAS module is not sending power to the starter,[same question, WHAT Voltage Measurement, WHERE?] all the relays and fuses in between are good. [There ARE NO relays or fuses between the CAS X13376/22 (Pin #22 of CAS Connector X13376) and the Starter Solenoid. See the link to CAS Starter wiring diagram below.] So whether the CAS module is bad or s squirrel chewed the wire. Plus i get the A0B4 code” engine start error starter operation

Originally Posted by Dolach

Here is a picture of the status of the CAS when I try to start the car:

View post on imgur.com

the red arrows means there's no voltage at this location. [There is NOT supposed to be voltage at the HALL, ELV, or KL15 WUP RS bar graphs during starter cranking or when START button pressed with foot on Brake/ Clutch which I presume were the conditions when you saved that screenprint? There is something "flakey" with 2.96 V @ KLR though]

QUESTION:
What is the build Month/Year of your 2007 328xi? That information is critical when assessing wiring diagrams as many changes occurred effective 3/1/2007 in the middle of the 2007 model run. Diagram below is for LATE 2007 model, build AFTER 3/1/2007, so may not be accurate if yours is < 3/2007.

The critical Data IF your INPA Screen is saved with START button pressed and foot on Brake/ Clutch is that "Terminal 50" or KL50 shows NO Voltage. Also strange is that the bottom-right bar graph shows .81 Amp current draw at KL50. That SHOULD be either "0.0" V when START button NOT pressed, or ~ 10 Amp when START pressed and KL50 is Activated.

Terminal 50 is the relay terminal in the CAS Module which is supposed to be ACTIVE when START is pressed (w/Brake/ Clutch). Think of it as Pin 87 of the Start Relay in cars with such a separate Starter Relay. That is the "Terminal" that sends power to the Starter Solenoid (NOT to be confused with the LARGE Red Wire from the Jumpstart Terminal which supplies "High-Amp" power to the Starter Motor directly. Here is the TIS wiring diagram for LATE 2007 CAS:
https://www.newtis.info/tisv2/a/en/e...system/uNYjfvY

Note Starter Motor M6510a and Black wire at Pin #22 of CAS Connector X13376. When START is pressed w/Brake/ Clutch, you should have 12V+ at that pin, and also in the E-box at the intermediate Connector, X6011, Pin #1, where wire continuing on to Starter Solenoid MAY become White (as it is at Starter).
https://www.newtis.info/tisv2/a/en/e...xi-lim/SL92ADs

I would suggest viewing the two screens attached and saving screenprints of YOUR vehicle's INPA Screens (1) with Brake Pedal Pressed & Gear Selector in P (or Clutch pressed & N if MT); (2) with Brake/ Clutch pressed as you press START (watch KL50 lines closely, and if they show voltage for an instant after pressing button, note how long until values return to 0. Normal starter cranking has those active for 1 to 2 seconds ONLY. If you will attach your screen prints of the above, we can suggest next steps.

My first attached screen is WITHOUT Brake pressed in my AT vehicle. When you press either Brake or Clutch, the circle should FILL/ Darken. Also check voltage of KLR with ignition ON and NOT trying to crank starter. Does Radio operate, and WHAT is KLR Value? Also, do you have ANY KL50 AMPS value when you are NOT pressing START button?

Originally Posted by Dolach

Yeah so I removed and connected directly to the battery because I didn’t have a multimeter to check the voltage If it had any voltage when trying to start the car. The solenoid and starter motor were working. But in the meantime I ordered a multimeter, put the starter back to its place, hooked the multimeter and tried to start the car. There is indeed voltage at the starter.. I think you are right, it was the starter all along.

WHERE did you measure Voltage at the Starter? There should ALWAYS be 12V+ at the LARGE Red wire that is B+/ Battery Power from the Jumpstart Terminal, as long as the Battery is connected & charged. What CHANGES (is SUPPOSED to change ;-) is the voltage at the small wire that connects to the Front of the Starter Solenoid, via Small Connector with the Spring Clip. See attached Bentley Photo. The socket in that connector should have Voltage ONLY when START button pressed w/Brake/ Clutch. You can "Hotwire" the starter by applying (CAREFULLY) battery voltage to the Starter Solenoid after removing that connector (X6510, same as shown in CAS wiring diagram above).

From what you have said, my SWAG is that your starter will crank the engine if you "Hotwire" pin @ X6510. If Ignition is ON (press START WITHOUT pressing Brake/ Clutch), if you hotwire that pin @ solenoid, engine should start. But it's easier to apply 12V+ to Pin #1 of Connector X6011 in the E-box as per links above.

Finally, the "A0B4" Code does NOT mean the Starter Motor is "Bad". That is ONE of multiple possible things that can set the code, but we just saw a situation where that code was saved in the CAS Module when the wire between the CAS Module and Starter Solenoid was open-circuit. If you will take the time to accurately report voltage readings and INPA screens under the conditions suggested, we can ALL learn something from your challenging situation.

George

[Dolach]

Changed the starter , did not work. I measured voltage positive on the bridge between solenoid and starter motor, negative on engine block, got 0.20V when trying to start. When i disconnect connector from CAS , measure voltage between connector and block when trying to start, I get 12.3V , so there is definitely current. Is it possible that the engine is seized?

[nsjames]

which is why I said to bar the engine over in my first post.

[Dolach]

Yeah next thing to try

[Dolach]

Engine rotates easily.

[Dolach]

Anyone has a clue about what is this KLR reading? I have only 2V when I am supposed to have 10V during a start

[Dolach]

Ok so finally solved the issue for those interested. There was a roasted transistor on the board of the CAS module.

[TdiMark]

I have the same issue. I think it was caused by an attempted throttle adaptation done incorrectly. I purchased the Schwaben/Foxwell 510 scanner to reset, but haven't found out how, or if, this scanner will work for this.

Any ideas?

[gbalthrop]

Originally Posted by TdiMark

I have the same issue. I think it was caused by an attempted throttle adaptation done incorrectly. I purchased the Schwaben/Foxwell 510 scanner to reset, but found out how, or if, this scanner will work for this...

WHAT ISSUE exactly do you have? If the Starter does NOT Crank the engine, that is due to an issue with the KL50 (Terminal 50) CAS Activation of the Starter Solenoid. THAT is the issue OP had.

Throttle Adaptation has NOTHING to do with the CAS Module. That function is done with INPA/ISTA connected to the DME Module.

If you have either INPA or ISTA, please describe your "Issue" in as much detail as possible, and if the Starter does NOT Crank/ Turn the engine at all, provide Fault Codes, Definitions & Details in CAS & DME.

I would check the MANUAL for the Foxwell 510, and see what Live Data (Terminal Voltages) it can read when connected to the CAS Module. See all the INPA CAS Live Data screens posted earlier in this thread. WITHOUT that data, we can only GUESS. There ARE ways you can simply use a DMM & patch cords at the E-Box to test KL50 Output from the CAS Module, but INPA or ISTA are a LOT quicker & easier.
George

[Bmw328xiBlue]

I have the same issue...
Does anyone here know if the ground strap on the left side of my engine block is only connected on one side, would that cause a no start no crank? I own a 2008 328xi, when the problem first happened I was sitting in a parking lot, I had just turned my car off and was sitting there for around 10 minutes. When I tried to start the car... nothing, the only thing you can hear is a buzz then a click on the right side of the engine block (When looking at from outside in front of the hood) near what I believe is the exhaust manifold. Any tips would be really helpful! thanks!