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josemedeiros007 10-02-2012 07:41 PM

528 engine sensor connector wiring guide.

Does anyone have a wiring diagram available that shows which connectors connect to which sensors?

My name is Jose F. Medeiros. I grew up in San Jose, California and have lived there since 1972. I am new to the list, and own a 1998 BMW 528 that I bought used with 180,000 miles on it from a friend. This is my second BMW, my first was a 1999 323is that I bought new from Allison BMW in Mountain View, California.

Does anyone have a wiring diagram available that shows which connectors connect to which sensors?

My 1998 BMW overheated a few months back, due to a broken water neck off the BEHR radiator while I was driving. After replacing the Radiator, with a Nissen, I started experiencing coolant loss, and white smoke out the tail pipe, I tried both K&W head gasket sealer, and Blue Devil, both temporary fixes, but helped for a short time.

My motor had 265,000 so it was decided to replace it a few weeks ago with a used motor with 110,000 miles, as the labor was not to be much more then replacing the cylinder head, but after the install, several codes are now popping up using my Peak Research code reader. This forum has been very helpful in helping to identify the issue's. Part of the problem was that the mechanic had plugged in the wrong connecter to the wrong sensor, so I took a chance and reversed them, and eliminated two of the codes OC and the ASC light on the dash not turning off, not to mention the engine runs much better and no longer hesitates. I am still getting a code for OE - Intake Air Temp Sensor and 44 - Evap Systems Purge Control Valve, which I feel is probably the sensor connectors reversed, which I am trying to locate.

Thank you each in advance for your help.

Jose F. Medeiros

acoste 10-02-2012 10:55 PM

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Hi Jose,

here is the complete schematic for the car:

not so straightforward to use, but everything is there.

here are the pictures from the items you mentioned. (inlet air temp sensor picture is for 540i)

josemedeiros007 10-03-2012 01:27 PM

1998 E39 528i Engine electrical wiring sensor connectors.
Thank you very much for the link to the wiring schematics, and for the two pictures that you posted, I really appreciate your help! Can I ask where you found those two pictures?

I have another newbie, novice question. On the purge valve, what does X6120 and Y6120 stand for, is that the BMW connector number stamped on the sensor electrical wiring connector, and sensor? If so, BMW engineers are a lot smarter then I originally thought, for not making each connector unique, and only fitting the correct sensor.

Sincerely, Jose F. Medeiros

acoste 10-03-2012 02:58 PM

Here is the schematic for the inlet air sensor (the 528i has no image): >> 5 E39 12/95 - 09/98 >> Components >> Component information >> B_Sensors, transducers >> Sensors, transducers >> B6205 Intake air temperature sensor (M52 engine)

Here is the schematic for the inlet air sensor (for the 540i with image): >> 5 E39 12/95 - 09/98 >> Components >> Component information >> B_Sensors, transducers >> Sensors, transducers >> B6215 Intake air temperature sensor (M62 engine)

Here is the purge valve: >> 5 E39 12/95 - 09/98 >> Components >> Component information >> Y_electromechanical components >> Electromechanical components >> Y6120 Charcoal filter valve (without M51 engine)

your engine is M52

josemedeiros007 10-04-2012 07:12 PM

2 Attachment(s)
Thanks again for the quick reply. I found one sensor wire connected to the Y6120 Charcoal filter valve aka Purge Valve that has a grey wire and a grey and brown wire, which I must assume should be connected to the X6205 Intake Air Temperature Sensor if I am reading the wiring color code abbreviations correctly GR & GR/BR (I am guessing it means Grey and Grey with Brown stripe) . The schematic for the Y6120 Charcoal Filter aka Purge Valve shows a RT/WS and BR.

Any idea what RT means? I also have a harness connected to the Evap Systems Purge Control Valve, which I can't find a schematic for, but that sensor connector has a brown wire, and a Blue with a red or orange stripe.

Thanks again for your time and help!

acoste 10-05-2012 12:24 AM

2 Attachment(s)
Hi Jose,

this spaghetticoder is pretty confusing, the 528i doesn't have an additional charcoal filter valve, but it has a fuel tank breather valve and the evaporative emission system is combined with this breather valve. This is also called purge valve. (The Evaporative Emissions System (EVAP) allows fumes from the gas tank to enter the engine to be burned, rather than vented into the atmosphere as an emission.)

Here you can find a picture of it:
and you can read there that this causes the evaporative 44 error code.

I searched for the intake air temp sensor, it is under the throttle body, see drawing attached.

RT is rot == red
here are the color codes:

Enjoy! :)

josemedeiros007 10-05-2012 08:06 PM

That wiring color code abbreviation chart saved the day, all three sensors were cross wired, and are now working correctly. I owe you a favor for your time and help, as well as it being very much appreciated.

Jose F. Medeiros
San Jose, California
Thomas A. Edison: 'I have not failed. I've just found 10000 ways that won't work."

acoste 10-06-2012 11:09 AM

You're welcome!

I also wanted to clarify this EVAP thing because I saw in the carfax of my car that this has been replaced. This is what I have found:

My car is a 528i 10/1997. I have checked the colors of the wires going to the fuel tank vent valve / charcoal filter valve / EVAp valve. It's red/blue and brown. When I check this on spagetticoder, it should be red/white and brown. I think the database has some errors here.

When I look for the fuel vent valve for my car:
spagetticoder >> Drive >> Engine (without M51 engine) >> Engine electrical system >> Digital Motor Electronics >> Actuator >> Fuel tank vent valve
it will bring up the Y6120 charcoal filter valve with red/white & brown cables.

Now if I choose the later model for E39 (post 09/1998) for example the MS43
there is a line:
".. ensure regeneration of the carbon canister when the fuel tank vent valve (TEV) is open .."

And then I go to the BMW-specific E39 acronyms (list and definition)
and search for TEV:
"TEV = evaporative purge control valve"

Again I checked an other (post 09/1998) model on spagetticoder:
Complete vehicle >> Drive >> Engine (DME Motor Electronics ME7.2 or DME Motor Electronics MSS52) >> Fuel system >> Fuel tank vent valve >> Fuel tank vent valve (without DME motor electronics MSS52)

it will bring up the Y6120 Charcoal filter valve with red/blue and brown cable. Notice that the brown cable has the name T_TEV.

So my conclusion is that the EVAP system valve is the same as fuel vent valve, and since there is no additional valve in the charcoal canister, BMW refers to the fuel vent valve as the charcoal filter valve.

I have also found that the very first picture I attached in beginning of this thread is a fuel vent valve for a 525i M54 engine.

josemedeiros007 10-06-2012 02:43 PM

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Thank you for posting that wiring color on your 97 E39 is different then the online schematic. My E39 has a production date of 3/98, and it has the same color sensor wires of Red / Blue Stripe & Brown wire as your BMW has to the two prong sensor connector.

My other sensor that I have plugged into air pump vacuum control valve by Peirburg has a
Red / White stripe & Green wire to the two prong sensor connector.

josemedeiros007 10-12-2012 06:24 PM

Just a quick follow up to let any one monitoring this forum, that my BMW IAT sensor had it's connector plugged into the Air Pump Valve switch, and the Evap Purge Control Valve had it's connector plugged into the IAT switch. I plugged the correct wires into the correct sensor's and now my Check Engine light stays off, and my BMW just passed smog. I want to thank everyone on this forum for all your help, it is very much appreciated.

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