Start No Idle Code 1215

[NolliM3]

The 95M3 starts, temperature sensor kicks (cold weather) up the RPM then RPM falls back to zero and the car dies.
So, I thought my idle control valve might be bad as I had recently cleaned it and it wasn't really
dirty yet it still idled rough. So, I bought another idle control valve; however, when I removed the
old ICV and transferred the hoses, I noticed that the snorkel looking piece had a crack where it
connects to the ICV. So, I placed some tape (the BMW cloth tape used on electrical) to cover it
so I can continue using the car.

So, after all the work of removing the intake manifold and putting it back together, I am getting the code
1215 MAF. So, I tried blowing or pulling air (by mouth) through the tape that covers the snorkel and could not.
So, I wanted to test the MAF ohms as well as the connector but the Bentley is confusing here. It mentioned a six
wire but mine has four. I doubt my 3.5 MAF is no good and want to be sure connector is supplying the correct
voltage and it communicating with the DME.

Meanwhile, I plan on buying the silicone ICV hoses since I have the silicone elbow.

[dworthy]

That code can also point towards a vacuum leak, so I would get the intake smoke tested. Might even be a good idea to get one of those amazon one's for 150 bucks as it will come in handy down the road and pay for itself pretty quick.

[NolliM3]

That code can also point towards a vacuum leak, so I would get the intake smoke tested. Might even be a good idea to get one of those amazon one's for 150 bucks as it will come in handy down the road and pay for itself pretty quick.

Thank you dworthy for responding. Based on Chris's suggestion several months or years ago, I do have a new intake smoke bought and yet to be used. I watch some videos on using it last night and need to get some mineral oil. I also bought the RallyRoad ICV silicone hoses yesterday as they were on sale that made them equal in price as the BMW ones. They should arrive this coming Wednesday; so, I'll do a vacuum test then after installing.

On testing, I have disconnected the MAF sensor harness from and started the car. The car should start and idle with the car been in limo mode...that's a default test and drive home safety. However, on first attempt the starts and immediately cut off. A stomp test reveals a flash of one. On second attempt, the car does the same. On third attempt, the car makes a backfire sound that seems to occur in the engine bay as if the spark meets excessive gas. A stomp test reveals code 1215 MAF. That seems to indicate to me that the DME isn't getting signal from the MAF sensor harness. Most of my research on code 1215 indicates that a wire break is a common problem.

If there is indeed a wire break, where is the supposed common breaking point. Here are the wires in the harness, see image below. There is a brown-I assume the ground wire, a red with white stripe...seems a power supply based on the thickness, a black which seems a trigger, and a white with yellow stripe, which could be going to the DME.





So the questions are which pin on the DME and where the power source to check for continuity.

[NolliM3]

This is the translation of code 1215 I saw in my research below as well as the electrical chart for the MAF that I am studying to translate where the wires go.

[dworthy]

Yes, the OBD-1 system is pretty basic, and the stomp codes just points you in a direction to start. The wiring can be an issue, so be sure to peel back the rubber boot and take a closer look at the wires.

[pbonsalb]

In my experience with OBD2 E36, the car runs with the HFM disconnected. It just runs rich. To me that makes it seem like a broken HFM wire would not prevent the car from starting.

No fuel might. Cold start can squirt a little but the car won’t keep running. The back fire is interesting—seems like fuel and spark are not being timed properly. Any chance the wiring harness was not reconnected properly when the intake manifold was reinstalled?

[NolliM3]

Well, this morning I put on my reading glasses along with a magnifying glass and took a closer look at the MAF harness connector...behold, I might have found the problem and had to learn how to take a macro image with my iPhone 7 for the forum to see.

[pbonsalb]

Does not look broken clean through. Unless it was touching metal and shorting out, I doubt the exposed power wire is the issue. Certainly worth taping or putting liquid tape over. Check the pins while looking in there to make sure none have pulled out.

[bmwdirtracer]

Have you considered that you set code 1215 when you started the car with the MAF unplugged? The code won't go away by itself just because you plug the MAF back in. Even if you only turned the ignition to the ON position while the MAF was unplugged, it would set an open circuit code, assuming that's what 1215 is?

When you had the manifold off, any chance you might have swapped the fuel hoses? TThey live right next to each other, and if you swap them, you get enough fuel to start and then die. I'd check fuel pressure.

[NolliM3]

Does not look broken clean through. Unless it was touching metal and shorting out, I doubt the exposed power wire is the issue. Certainly worth taping or putting liquid tape over. Check the pins while looking in there to make sure none have pulled out.

I have been thinking about this all day...the rain prevented from further exploring. Yes, I doubt the exposed wire too as it could not touch anything...the actually round connector pin seems well-seated in the harness. So, while it rained, I decided to test the old ICV coil resistance value to compare with the Bentley...I got terminals 1 - 2 =28.2 ohms, 2 -3 = 23.5 ohms, and 1 - 3 =34.6 ohms which are all within specs. So, my old ICV is good. So, now I am wondering whether the cheap replacement I got is any good. So, now I am leaning towards a conclusion that I might have had a vacuum leak with the old ICV that caused the problem. Then, I patched the vacuum leak but replaced the ICV with a non-working new (don't laugh) Chinese one.

[pbonsalb]

I doubt the problem is the ICV.

[NolliM3]

Have you considered that you set code 1215 when you started the car with the MAF unplugged? The code won't go away by itself just because you plug the MAF back in. Even if you only turned the ignition to the ON position while the MAF was unplugged, it would set an open circuit code, assuming that's what 1215 is?

When you had the manifold off, any chance you might have swapped the fuel hoses? TThey live right next to each other, and if you swap them, you get enough fuel to start and then die. I'd check fuel pressure.

I had disconnected the battery to clear the code. I had tried testing the harness for voltage, but I had the key turned to on instead of start position.

[NolliM3]

I doubt the problem is the ICV.

Well, at least the old ICV did start the car just did not idle and the vacuum leak might have been the cause. I'll wait until Wednesday to test the new ICV hoping the silicone hoses arrive on schedule (the post office delivery is so sketchy these days).

[pbonsalb]

Was that before you removed and reinstalled the intake manifold? I like the idea of a mis connected wire — IAC and TB harness are similar at least in obd2 and crank position sensor and fuel injector area wires can be mixed up again at least on obd2. And dirtracer suggested crossed fuel lines if you disconnected those.

[NolliM3]

Was that before you removed and reinstalled the intake manifold? I like the idea of a mis connected wire — IAC and TB harness are similar at least in obd2 and crank position sensor and fuel injector area wires can be mixed up again at least on obd2. And dirtracer suggested crossed fuel lines if you disconnected those.

Yes, that's before removing the intake manifolding and installing the new ICV. It's all most impossible to mix up wires on the 95M3 as the only wires removed were the ICV and the temperature harness. The ICV harness is not long enough to reach the temperature sensor. Also, I had cleaned up the fuel lines so cannot mistake any as the return line is way shorter than the supply line. The new silicone ICV hoses are on track to arrive tomorrow, so eager to test that new ICV which I am suspecting. I also tested that exposed wire on the ICV harness to the round plug for continuity, and it is good, not broken. I am putting back my old ICV.

[NolliM3]

Well, the post office delayed the delivery of my silicone ICV hoses; however, I now understood the problem clearly and will demonstrate with pictures. It all started with referencing the Bentley manual which shows the position of each pin on the ICV.



Note the center tab in the above image...when the ICV is held in its retainer, it's lays flat like this picture of my original ICV below.



So, when the above layout of the ICV, the center tab is on the left as noted by the yellow arrow in the image below.



The new ICV has the center tab to the right which would make the pins of the ICV harness connect incorrectly to the pins on the new ICV.




So, in essence with the new ICV the wire harness would connect to the pin 3 instead on pin 1 and why the car would not start because the ICV is not powered properly...the DME thinks there is no ICV and blames the MAF sending code 1215.

[shadowpuck]

interesting - so, the car now starts and runs with the original ICV?

[bmwdirtracer]

Yeah, um, I'd guess your hypothesis is wrong, sorry. Bentley is wrong more often than you know. I'm wrong sometimes too; let us know what you find.

[pbonsalb]

I agree that I don’t think we are done yet. Waiting for new hose to replace the cracked ICV hose makes sense, though.

[NolliM3]

interesting - so, the car now starts and runs with the original ICV?

Not yet, I am waiting for the silicone hoses to arrive to replace that new ICV back to the old one...should be here tomorrow as it’s in my city main distribution since last night. It will run because it did before but because of the vacuum leak it didn't idle.

- - - Updated - - -

Yeah, um, I'd guess your hypothesis is wrong, sorry. Bentley is wrong more often than you know. I'm wrong sometimes too; let us know what you find.

Sure will!

- - - Updated - - -

I agree that I don’t think we are done yet. Waiting for new hose to replace the cracked ICV hose makes sense, though.

Surely will although it might rain tomorrow.

[NolliM3]

I agree that I don’t think we are done yet. Waiting for new hose to replace the cracked ICV hose makes sense, though.

Well, it seems that you're correct about not done yet. So, now I am back to square one where she starts, run for a few second, then dies. What's interesting is when it does that the stomp check reveals a code of one (1); yet, if I remove MAF harness, I get code MAF 1215.
Spark plug-new, Fuel pump 4 months old with known stock fuel pressure, new fuel pressure regulator, new fuel hose line (500psi), fuel filter 1yr old, fuel injectors recently refreshed. Both ICV and MAF were cleaned with mass air flow sensor cleaner.

I have a new five prong fuel pump relay but the old four prong one is currently installed. The weather prevented doing vacuum leak test but doubt I have any leak with the new silicone ICV hoses installed. All intake hoses are now silicone.

When the car starts, the RPM does its usual cold start increasing the RPM, but the needle just return to zero then the car dies...so I am wondering whether the throttle position sensor is contributing. I can put the computer on the car (DIS) despite easily getting data disturb when connecting.

[pbonsalb]

Be careful with relays. While bosch and bmw look similar the pins can be oriented differently and you can fry your wiring harness using the wrong one. I know from experience. Make sure you use only the correct color bmw relay. I forget whether it is green or orange for the fuel pump.

[NolliM3]

Be careful with relays. While bosch and bmw look similar the pins can be oriented differently and you can fry your wiring harness using the wrong one. I know from experience. Make sure you use only the correct color bmw relay. I forget whether it is green or orange for the fuel pump.

It's a good thing you said this...I was going to try a dark red or brown four prong one I have laying around. The new fuel pump relay I got (from ECS and it's BMW) is green but the five prong bothers me...apparently, the new ones are five prong.

[bmwdirtracer]

There's no connection for the fifth prong....BUT pbonsalb is ABSOLUTELY correct! You have to match the diagrams on the relays EXACTLY! For instance, if you put a "normal" five-prong relay into the Secondary Air slot, you connect a full time ground with an unfused hot, and melt the wiring harness, and probably the DME also! Relays do not all work the same way; it is crucial that you understand the diagrams on the relay, and perfectly match each pin to the slot it's going in!

[NolliM3]

Today, I swap in the new fuel pump relay...no change in symptom, checked to make sure oxygen sensor relay is powered with the key turned to start, good, relay powered. So, now the throttle position sensor test reveals no continuity between pin 1 and pin 3 and no change with the throttle wide open. However, I have continuity between pin 1 and pin 2 of (TPS) but it doesn't change with the throttle wide open.

So, ordered a used BMW TPS from a recycling company of eBay for $20 including shipping and it shall be here in a few days.