Sun is shinning on me today!!!!!!!!!!
Well, after one and a half years of owning my 94 540, I finally figured out
why I was getting this code despite changing the old sensors with new
sensors. My symptoms were a rough idle when cold which worked itself out when warmed up. All intake manifold gaskets (front, rear and 4 bottom) were replaced along with a fuel pressure regulator, new fuel injectors, new ignition coils, new motor mounts and a new idle control valve. After all these items were replaced, I was still getting the 1221 code but couldn't figure out why I was getting 18-21 MPG and the rough running in the morning. So I said to myself, "Let's check the 12V signal to the O2 sensors coming from the relay when the car was started." So I pulled out the voltmeter and didn't get any 12V signal from either O2 sensor. Next step was to open up the E-Box and pull the relay. The relay on my car was underneath in the middle and closest to the passenger side wheel. I probed the "hot" 12V terminal on the relay receptacle and I was indeed getting 12V.
I then proceeded to the stealer for the replacement relay ($15) and reinstalled. Reset the battery and started up. DME now returns a series of 1444 codes which means everything is clear. Hope this helps someone else!
Sun is shinning on me today!!!!!!!!!!
THANKS!
Originally Posted by new540iowner
I am about to order 2 O2 sensors for my 94 530i that throws 1221 code. I want to just change this relay as well for preventive action. Could anyone tell me the part number and where this relay is located?Originally Posted by DaCan23
Thanks!
94' AlpineWhite 530i, 5 spd Auto, 112K miles, Mfg in 4/93
i believe it is 61361378238
Alusil, Dinan DME | ITG Air Filter | Eibach/Bilstein HD | 26/20 Swaybars | Iridium plugs | Depo/ProLumen HID | Optima batt. | no AC | Stoptech brake lines, Frozen rotors, brass bushings, Superblue