5/18/21 12:30 p.m.

An old friend loves his E46 wagon with 5-speed.  Yes, he knows it's a unicorn.  But he's struggling with it not wanting to run for over a minute.

Here's his analysis so far (from his craigslist ad)

Car starts and runs beautifully from a cold start, but then stalls after about one minute of idling and then cranks but will not restart. I have not driven it on the road since last July for fear of it dying and needing to be towed home.

I have been trying to troubleshoot this problem for about 9 months now. Parts that I have replaced with new OEM parts in this time (with 0 miles driven on them):

- DME, EWS, and key fobs have been fully tested and OK’d
- fuel pump
- fuel filter
- fuel pump relay
- main relay
- intake camshaft sensor
- battery (alternator has been tested and puts out 14.4V)

- dash beeps when key inserted into ignition
- all dash lights light up at ignition on
- at cold start, engine fires right up and idles smoothly
- at engine running, red battery light, yellow warning triangle light, and red brake light stay lit
- engine runs smoothly for a minute or two and then dies suddenly
- turn ignition off, remove key, reinsert key, then no dash beeping
- at crank, no start, and no dash lights except for odometer.
- throwing P1350/P1344 codes on Schwaben scanner right now





Tyler H (Forum Supporter)
Tyler H (Forum Supporter) UberDork
5/18/21 1:01 p.m.

In reply to DWNSHFT :

From the ad: 

"have also made the following retrofit upgrades:

- BMW alarm system (coded and activated)
- BMW Business CD player
- replaced LCM with one that has automatic headlights and a fog light switch (although I never got around to retrofitting fog lights)"

I'd be taking a good hard look at that alarm module.  Maybe also swapping back the LCM.  Check grounds, etc.  Look for rotten intake boots, which are common every 2 years.  

5/18/21 1:22 p.m.

Thanks for posting on my behalf, DWNSHFT!  I am the "old" friend who owns this car, so I thought I'd chime in...

I have already tried swapping the original LCM back in, and tried deactivating the alarm module, but those produced no changes.  Intake boots are also good.

I'll have to look up where all the ground connection points are and then try sniffing those out.

golfduke Dork
5/18/21 1:23 p.m.

It's definitely electrical, and my bet is the alarm system.  In the E46, I think there are 3 or 4 different DME's that contribute to the security system I wanna say. 



VW_Fritzi New Reader
5/18/21 2:35 p.m.

Here's some history on the sequence of events that may clear things up:

Dec 2016: Car purchased from original owner
Mar 2017: Used LCM w/ auto headlight installed.  High beams only work w/ flash-to-pass (known issue)
May 2017: Used BMW alarm modules installed (motion sensor, tilt sensor, siren, control module), but not activated yet.  The car had all of the wiring already built in, so this was plug and play (minus the activation).  No issues resulting from this.
May 2020:  Car starts having intermittent problems with stalling and/or crank/no-start.  At first this happens once every few days and would eventually restart if I let it sit 5-10 minutes.  But over time, the frequency of these events slowly increased, and the length of time to able to restart became greater.
July 2020:  The crank/no-start situation becomes so bad that it is pretty much a constant crank/no-start problem, so I park the car and begin troubleshooting over the next 9 months.
~Oct 2020:  On a whim, I finally get around to activating the car alarm with BMW Scanner 1.4.0.  No change to the crank/no-start problem.

In those 9 months of troubleshooting, I swapped out all the parts in the original post here with new.  The only thing that got the car actually running again was when I replaced the fuel filter.  That was the first time the engine fired up in about 9 months.  But it had also been sitting for several months without even having been turned over.  And, it is still stalling (like it just stops immediately) and then will not restart unless I let it sit for several hours to a day, and then I am back to starting OK, then dying after a minute or so, and then crank/no-start.


Slippery UberDork
5/18/21 3:11 p.m.

My gut feeling was the LCM as there are A LOT of things that run through that, but you drove it for a few years with the new LCM. 

I have nothing. 

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
5/18/21 3:42 p.m.

Will it fire on carb cleaner when it's exhibiting the no-start condition?

02Pilot UltraDork
5/18/21 4:56 p.m.

What are the BMW proprietary codes (not P-codes)? How many are active? Have you cleared them, and if so, how many come back?

VW_Fritzi New Reader
5/18/21 5:02 p.m.

Things on my to-do list based on feedback I've received here and elsewhere in the past couple of days:

1.  Swap out LCM for original one
2. Replace ignition switch
3. Replace crankshaft position sensor
4. Test for spark at no-start condition
5. Try starting using carb cleaner

I'll have to wait to try all these until my new ignition switch comes.  I tried pulling it apart to check the internal contacts, but I flinched and the spring popped out, so I can't get it back together.  Blargh.


VW_Fritzi New Reader
5/18/21 5:09 p.m.

I can't check at the moment until I get my new ignition switch, but previously I was getting this laundry list of codes:

01 - Engine-DDE Diesel Electronics DDE3.0
     EF - DME Misfire, cylinder 2
     F2 - DME Misfire, cylinder 5

02 - EWS Vehicle Immobilizer
     0F - Voltage supply EWS3 control module

04 - SPMBT Mirror memory, passenger
     7  - SPMBT: Mirror motor, potentiometer, vertical

05 - SPMFT Mirror memory, driver
     4  - SPMFT: Mirror-adjustment switch, open circuit
     5  - SPMFT: Mirror heater, open circuit
     7  - SPMFT: Mirror motor, potentiometer, vertical
     8  - SPMFT: Mirror motor, potentiometer, horizontal
     9  - SPMFT: Mirror motor, vertical, open circuit
     B  - SPMFT: Mirror motor, horizontal, open circuit

06 - SZM Switching centre, centre console
     8 - SZM: Seat heating, seat cushion, left, open circuit
     5 - SZM: Undervoltage, seat heating

07 - KOM Instrument cluster
     11 - KOMBI: Thermal oil-level sensor
     BE - KOMBI: Data-filing difference to central light module
     F4 - KOMBI: No CAN identification
     F6 - KOMBI: No CAN identification (DME)
     F8 - KOMBI: No CAN identification (DME)

08 - LSZ Light switch center II
     14 - LSZ2: Wire, brake-light switch, open circuit
     1E - LSZ2: Control-unit fault in HVAC section
     1F - LSZ2: Coils, stepping motors, faulty
     21 - LSZ2: Headl. v.a.c., front load sensor, open circuit
     22 - LSZ2: Headl. v.a.c., front load sensor, short circuit to earth
     23 - LSZ2: Headl. v.a.c., rear load sensor, open circuit
     28 - LSZ2: Terminal R missing
     29 - LSZ2: Terminal 15 missing
     36 - LSZ2: Turn indicator, front left, faulty
     39 - LSZ2: High beam/side light, left, faulty
     3A - LSZ2: High beam/side light, right, faulty
     3F - LSZ2: Turn indicator, rear left, faulty
     40 - LSZ2: Turn indicator, rear right, faulty
     41 - LSZ2: Dipped beam, right, faulty
     42 - LSZ2: Dipped beam, left, faulty

10 - RAD Radio
     0 - RAD: Transport mode active

12 - ZKE Central body electronics
     29 - GM: Relay for central locking, unlocking
     D  - GM: Power window: anti-trapp. mechan. driver's door
     E  - GM: Power window: anti-trapp. mechan. passenger door
     F  - GM: Power window: anti-trapp. mechan. driver, rear
     10 - GM: Power window: anti-trapp. mechan. passenger, rear
     81 - GM: DWA alarm memory: door contact, driver's door
     8A - GM: DWA alarm memory: passenger-comp. sensor, front
     88 - GM: DWA alarm memory: engine bonnet


Tyler H (Forum Supporter)
Tyler H (Forum Supporter) UberDork
5/19/21 12:23 p.m.

That laundry list of codes strongly points to a ground / voltage supply issue to me.  Especially with that EWS supply voltage issue.  

A compression test and fuel pressure test would be a good thing to baseline, just to ensure that there is adequate fuel supply and the engine is fundamentally healthy.  I'm guessing the fuel filter swapout start scenario was a fluke.  

Add to the list -- test the voltage straight off the battery vs off the jump start lug in the engine bay, to see if there is a difference.  I'd also look at the OBD2 reported voltage to see what the DME is seeing.  

Take a real hard look at the battery ground cable in the trunk.  Use jumper cable from the neg terminal to the ground lug on the body to supplement the ground cables.  I would also try it between the engine ground and the body up front.

Good luck!


VW_Fritzi New Reader
5/24/21 11:04 a.m.


The new ignition switch arrived this weekend, and I installed it last night.  The car started right up as normal for a cold start lately, but this time there were no dash warning lights that stayed on.  It idled fine for a good 10-15 minutes without stalling.  I turned the key off, then cranked again and it started right up, still with no warning lights.  I did the on again, off again cycle several more times, and each time produced none of the former issues.

I also put both of my scanners on it, and neither one produced any trouble codes.

I'm going to take it out for some short test drives and make sure everything is working properly, but for the time being, it looks like I've got my car back!  Thanks for everyone for the troubleshooting suggestions (although it was ultimately someone who responded to my Craigslist ad that offered the winning solution).


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