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Discussion Starter #1 (Edited)
Hey guys,

I've posted this on Bimmerpost when the issue first occurred, but despite some kind curiosity and comments shown to it, I have yet to receive any good advice. I could be completely wrong, but it seems like Bimmerfest has more problem solvers, so I'm copying and pasting my inquiry here.

The car had sat in my driveway for a month and I drove it about 7 miles to get to work. I didn't notice anything odd, it drove fine. On the way home, I was at a stop and when I stepped on gas, car jerked a bit (maybe misfires) and went into limp mode. Got the drivetrain warning on dash at this point, so I casually pulled over, turned off ignition, then was able to restart the car. It drove a couple miles and went into limp mode again and I couldn't get it to start this time.

I scanned using ISTA+ after getting the car towed home and it had several fault codes stored from when I had low battery in winter (battery wouldn't charge on super cold days around -35 degrees), so I jotted them down and cleared them.
I tried starting the car, but it only cranked and failed to start. Then, I scanned again and got 1 code-- 1F4A10 Relay, ignition and injectors, activation: Line disconnection.

Suggested service action in ISTA is to check DME, relay for ignition and fuel injection and I have yet to find where this relay is located. I would appreciate if you could point me in the right direction..

Things that I've done so far and questions I have:

-Replaced spark plugs and ignition coils. This didn't do shit.
-Confirmed low pressure fuel pump not priming when ignition switched ON
1009820

-Back probed connector while connected AND removed from pump, with ignition ON--measured ZERO voltage
-Back probed the other end of wire that goes into EKP module (A98*2B connection)--no voltage
-Checked wires in the other connector on EKP module (A98*1B, black on the left in pic)
-Power feed from rear power distribution box measured 12V (fuse & embedded relay OK)
-Also on this connector are 2 PT CAN wires (High and Low) AND a Terminal 15 WUP wire
-When inactive, both should read 2.5V
-When active, H should be 4V, L should be 1V.
-With ignition ON, both measured about 2V.
-"Terminal 15 WUP" wire somehow tripped the dash when I tried to measure the voltage, dash showed drivetrain malfunction message again and chimed. Voltage was all over the place--What voltage is this wire supposed to have???

-Swapped EKP modules with a used one off of eBay, the car still wouldn't start.

Next step:
-Find out what the hell Terminal 15 WUP is and where
-Check voltage within EKP module-- positive lead on power feed from rear power distribution box and negative lead on ground (not body, but brown ground terminal in the connector) to see if there's an issue with the wire
-Study PT CAN more..

Dumb question: even if my LPFP was bad, I should still have the battery voltage at the connector to the pump from the EKP module, correct?

Sorry for the eye cancer, guys. Just trying to get some help..

Thanks,
 

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............- 1F4A10 Relay, ignition and injectors, activation: Line disconnection...................

...................Suggested service action in ISTA is to check DME, relay for ignition and fuel injection and I have yet to find where this relay is located..................
Based on code I would look for problem with #2 relay in the Integrated Supply Module.
Confirm you have power at pins 5 & 6 of the module w/ignition on.

Drill into the blue text in diagram to find locations and related info.
 

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Discussion Starter #3
Based on code I would look for problem with #2 relay in the Integrated Supply Module.
Confirm you have power at pins 5 & 6 of the module w/ignition on.

Drill into the blue text in diagram to find locations and related info.
Thanks for the reply and suggestion.
As for the integrated supply module (="integrated voltage module"="power distribution box"), I found after some googling that in F chassis vehicles, it's the "Z11" module shown below.
Unlike its counterpart for previous gen, it seems like the "cover" is molded over the PCB (I've seen a video of a dude on youtube heat this up and cut through using a knife..)

Question: If this module is bad, would it subsequently cut power to fuel pump module (EKP)? I was wondering if it would mess with PT CAN and/or Terminal 15 WUP to prevent EKP from sending a proper output to the low pressure fuel pump (i.e. if ignition relay failed).

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1009815
 

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.......... If this module is bad, would it subsequently cut power to fuel pump module (EKP)? I was wondering if it would mess with PT CAN and/or Terminal 15 WUP to prevent EKP from sending a proper output to the low pressure fuel pump (i.e. if ignition relay failed).........
Seems reasonable to me that if the DME doesn't have power it can't communicate with or energize connected modules like the EKPS.
You should be able to get to pins 5 and 6 of the IVS at the Z11*3B connector. I would not look any further until I knew these pins have power. Since the car sat for a month, I would also disconnect all connectors at ISM/IVM and check the wiring for evidence of rodent damage.
 

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Discussion Starter #5
Seems reasonable to me that if the DME doesn't have power it can't communicate with or energize connected modules like the EKPS.
You should be able to get to pins 5 and 6 of the IVS at the Z11*3B connector. I would not look any further until I knew these pins have power. Since the car sat for a month, I would also disconnect all connectors at ISM/IVM and check the wiring for evidence of rodent damage.
Gotcha. I'll look into this first thing in the morning.
Also, do you know which one is the #2 relay in the picture above?
I was wondering, especially with these kinds of "embedded" relays that you cannot remove to bypass, how would you go about diagnosing if they're good or bad?

Thanks again for the support.

As you could tell from my post, I'm a noob. But instead of throwing more money and time away dicking around with part swaps, I'm trying to take a more systematic approach.
 

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Discussion Starter #7
Here's the pinout for the Z11-3B connector. This is the cable end, so the module pins are the mirror image of this.
With the connector removed and ignition on, all (6) pins at the module should have 12v Confirm with a DMM measuring to ground.

With a sealed module, replacement is the best option. Looks like it's a $140 part.
I went and measured the voltages with a DMM with the Z11-3B connector on AND off, and ignition on.

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Looking at the wiring diagram you've linked, it seems like Pins 1-3 are for Terminal 15N, Pin 5 for injection, Pin 6 for ignition, and I have zero clue what Pin 4 is for, but it seems like some kind of a bus wire judging from the voltage.
When I measured Pin 4, I heard a clicking sound either from the ISM or my multimeter and the multimeter got shut off..

Anyhow, I had some very minuscule voltage on every wire with the connector removed. With it connected, battery voltage was detected except Pin 4-6, but I think that thin wire on Pin 4 is normal to measure lower than 12V (correct me if I'm wrong).

Dumb question: Was I supposed to measure 12V on these pins even with the connector removed from the module while ignition switched on? (because that wasn't the case)

I'll go ahead and order a replacement and see if it solves the problem.
I wish there was a way to confirm this is the reason why EKPS isn't outputting any power to LPFP.

By the way, after I plugged everything back on and scanned the car again, I ended up with a few more fault codes on top of 1F4A10 (Injection) previously mentioned;
1F0515- Valvetronic, supply voltage: Line disconnection
133104- Valvetronic relay, activation: Line disconnection
Hmm...

I also checked the wires for any apparent damages, as well as pins on the module for any signs of water ingress.
Everything looked OK despite the spider web and debris collected on the power line. I cleaned the debris before putting things back together and confirmed 12V on the power line.

1009945
 

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New codes are likely due to unplugging the module.
Pin 4 energizes the coil on relay 2 (that in turn puts power on pins 5 & 6) by completing the circuit to ground thru the DME.
No power to pins 5 & 6 is the problem I suspected based on 1F4A10 code. Now the issue is why. Failed module, no coil ground thru the DME or DME problem.
You can verify continuity of the wire from pin 4 of IVS to pin 8 of DME. If wire is good, then replace the module.
 

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Discussion Starter #9 (Edited)
New codes are likely due to unplugging the module.
Pin 4 energizes the coil on relay 2 (that in turn puts power on pins 5 & 6) by completing the circuit to ground thru the DME.
No power to pins 5 & 6 is the problem I suspected based on 1F4A10 code. Now the issue is why. Failed module, no coil ground thru the DME or DME problem.
You can verify continuity of the wire from pin 4 of IVS to pin 8 of DME. If wire is good, then replace the module.
Understood.

Quick confession to make-- I just realized after revisiting your previous comment that I misunderstood the instruction and back probed the connector instead of measuring the voltage on pins on the actual module..

I'll try to locate the A211-5B connector on DME. Seems like there are a lot of things to remove to gain access to DME since it's attached to the intake manifold.
I'd better take a lot of pictures to remember how to put everything back together :D

When I check the continuity on pin 8 of this connector, am I supposed to place one lead on it and the other on pin 4 of IVS and use the continuity setting on DMM? Or, place +'ve lead on pin 8 of DME and -'ve lead on a body ground?


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...........I just realized after revisiting your previous comment that I misunderstood the instruction and back probed the connector instead of measuring the voltage on pins on the actual module.......

........When I check the continuity on pin 8 of this connector, am I supposed to place one lead on it and the other on pin 4 of IVS and use the continuity setting on DMM..........
I could tell from your table that you measured the connector both times, rather than the module pins. I wasn't sure you would be able to back probe the connector while attached to the module and pin voltage would give us some info. It would be interesting to know the pin voltages, but it won't change the path forward.
Put one lead on pin 8 and the other on pin 4. Use the Ohms/resistance scale. Should be less than 1 ohm. If DMM has a Diode selection, it should provide a nice BEEP if resistance is acceptable.
Most likely the IVS is the problem. I wouldn't spend too much time disassembling car to check continuity. Most shops would simply replace the module at this point.
 

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Discussion Starter #11
I could tell from your table that you measured the connector both times, rather than the module pins. I wasn't sure you would be able to back probe the connector while attached to the module and pin voltage would give us some info. It would be interesting to know the pin voltages, but it won't change the path forward.
Put one lead on pin 8 and the other on pin 4. Use the Ohms/resistance scale. Should be less than 1 ohm. If DMM has a Diode selection, it should provide a nice BEEP if resistance is acceptable.
Most likely the IVS is the problem. I wouldn't spend too much time disassembling car to check continuity. Most shops would simply replace the module at this point.
You're absolutely right. My wrist wasn't flexible enough to back probe the connector as-is.
After disconnecting the connectors to check for any water ingress and damages, I just dismounted the module from the bracket it was seated on and carried on with the measuring.
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When I get off work tonight, I'll check the pin voltages too just to add them to this log and take a good look at the layout in engine bay to see if there's a relatively easy way to access the connector on DME.

Besides, I've placed an order for a new module with FCP Euro. ETA is next Tuesday, but I think they typically only take 3 days for delivery.

I'll keep you posted, and thanks again for the continued support.
 

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Discussion Starter #12 (Edited)
I could tell from your table that you measured the connector both times, rather than the module pins. I wasn't sure you would be able to back probe the connector while attached to the module and pin voltage would give us some info. It would be interesting to know the pin voltages, but it won't change the path forward.
Put one lead on pin 8 and the other on pin 4. Use the Ohms/resistance scale. Should be less than 1 ohm. If DMM has a Diode selection, it should provide a nice BEEP if resistance is acceptable.
Most likely the IVS is the problem. I wouldn't spend too much time disassembling car to check continuity. Most shops would simply replace the module at this point.
Seems like the replacement part will arrive on Saturday as opposed to next Tuesday!
I measured the voltage on module pins as you mentioned just as a redundancy, and the readings were very much the same as what I previously obtained from back probing the connector while plugged in.

By the way, I joined BMW CCA the other day after seeing your signature.
I entered the raffle for that M5 haha.
 

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Discussion Starter #13 (Edited)
I just replaced the suspect IVS with a brand new one that arrived today. Sadly, the issue remained the same, where there was no power at pins 5 and 6--voltages on these pins measured close to zero (2.5mV).
I had cleared the codes prior to trying to start the car after the replacement, and ended up with the same 1F4A10 code.
Per your previous comment, I'll check continuity from Pin 4 on IVS to Pin 8 of DME connector in the picture below.
It seems like I don't need to remove a bunch of stuff to access it.

1010244



One thing I noticed while replacing the module is that there was a constant flickering noise from somewhere.
I couldn't tell exactly where it was coming from, but it was near the brake booster.
I had to get really close to the area shown in the video to hear this, and it continued even with the ignition off.

I was wondering if this sound would have anything to do with the issue I've been having.

As if not having a working car wasn't bad enough, I noticed now my hood latch won't release anymore.
Looks like I'm going to have to remove the wheel and fender liner to manually pull on the cables to release the latch.
 

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Noted, report back after checking wire continuity.
Confirm there are no other ISTA codes. An issue with the anti theft system, might prevent DME from powering fuel and ignition.
Have a helper push down on the hood while you pull the release might open the hood.
 

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Discussion Starter #15 (Edited)
Will do.
As for the codes, I had only had the 1F4A10 code prior to diagnosing IVS as well as 801A4C for undervoltage.
I didn't think much of 801A4C as I thought it was from using ISTA without a trickle charger connected.
After removing and plugging the connectors back in to the old module, I had additional codes of 1F0515 and 133104.

1F050515-Valvetronic supply voltage: line disconnection
133104- Valvetronic relay, activation: line disconnection


Then, I replaced the module yesterday and tried to start the car, ended up with one more code;
119404- Rail pressure sensor, signal: permanently stuck

Not sure what the "existent" column on ISTA represents (literally whether the condition is actually present or not?), but it showed "no" for all 3 codes above.

After clearing these codes and re-scanning, the car's back to having only 2 codes of 1F4A10 and 801A4C.

As for the hood, thanks for the tip. I'll ask my wife to push down on it while I pull the lever, or vice versa.
I just ordered a grand cherokee for her, so I'm sure she won't mind lending a hand.

Have a great rest of the weekend!
 

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Discussion Starter #16
Noted, report back after checking wire continuity.
Confirm there are no other ISTA codes. An issue with the anti theft system, might prevent DME from powering fuel and ignition.
Have a helper push down on the hood while you pull the release might open the hood.
I was able to open the hood by pushing down on it while the wife was pulling the lever.
As soon as I opened it, I found this-- my T-pin case all crushed underneath the hood.
1010357


Just to gain some room to work with, I unplugged A211*1B connector.
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Then I went and checked continuity between Z11*3B Pin 4 and A211*5B Pin 8.
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As you can see, I shamelessly probed the terminal on DME from the front. I was trying to back probe the wire, but there were way too many wires in this harness and I couldn't really see it from the back.

By the way, when I switched ignition on with A211*1B and 5B connectors removed, I heard some noise coming from the back. I still didn't hear my low pressure fuel pump prime, but heard a constant noise that resembled air being blown. It went away after I plugged everything back in.

I'm ready to tackle next steps.
 

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Discussion Starter #17
If there's something that caused the fuses F04 and F05 to blow, could the same condition have blown the same fuses on the new IVS that I've installed immediately upon switching ignition on?
When I get home tonight, I'll heat up the old module and try cutting it open to see if the fuses blew.
 

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OK, with continuity good, we're down to .......
-Bad DME
-Alarm or other issue preventing DME from grounding pin 8
- IVS fuses blow immediately

Are you using E-net cable with ISTA or K+DCan?
You should be able to test your IVS w/o cutting it open. Refer to schematic in my earlier post.
Put +12v on Z11*1B. Put -12v (chassis ground) on Z11*3b pin 4. This will pull in relay and will put 12v on Z11*3B pins 5 & 6 if fuses are good.

801A4C is related to the alarm system. Run the test plan for this code.
 

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Discussion Starter #19
Hmm..

Yes, I'm using an E-net cable with ISTA.

As for testing IVS, should I get cables like what's in the picture below and put one end on +'ve terminal of the battery and the other end on Z11*1B to put +12v? Or, can I just use skinny jumper wires that I normally use with my multimeter like the ones with alligator clips in the second picture.

And how do I put -12v on Z11*3B pin 4 using a chassis ground?
Do I simply clip one end on the pin and the strut tower on the other end?
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1010511


I'll run the test plan for 801A4C as well before I report back.

Thanks!
 
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