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Thread: Oxygen sensor heater error codes 2222 and 1264

  1. #1
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    Oxygen sensor heater error codes 2222 and 1264

    Hi I have a check engine with the codes 2222 and 1264. the error code list says the error is stored if there is a break or short in the oxygen sensor heater, sensor heating relay or wire form dme control unit.

    I checked the oxygen senor heater with a volt meter. Both banks have same resistance, no breaks. I checked power to the sensor heater, both banks recieve 12 volts when the car is in the on position.

    The car drives fine even when cold. If I reset the DME, the engine light stays off that whole day, no matter how long I drive it. The next day I start it and the check engine comes on again. It seems like an intermitent connection issue first thing in the morning. I checked the DME solder pins 70 and 71 and resoldered them even.

    Anyone had a similar problem?

    Thanks

    Any ideas?

  2. #2
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    Just an update, I replaced the oxygen sensor for that bank, just to be sure. The problem is the same. I have also noticed that th check engine only comes on, on a cold morning. I once warm up the DME before starting and the light does not come on. I am now thinking solder issues or caps on the DME. Will post again

  3. #3
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    Orange or red CEL?

  4. #4
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    Quote Originally Posted by 8eights View Post
    Orange or red CEL?
    Red cel, the check engine

  5. #5
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    relay in same compartment as DME... one closest to firewall... do you have one of those or are there only 2 relays?

    If you have the third one, closest to firewall, that one drives the pre-heaters for O2 sensors

  6. #6
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    Quote Originally Posted by cartoonz View Post
    relay in same compartment as DME... one closest to firewall... do you have one of those or are there only 2 relays?

    If you have the third one, closest to firewall, that one drives the pre-heaters for O2 sensors
    Thanks, I thought because I have a voltage at the sensors for the heaters, the relay is fine, but it could be an intermitent problem. I will switch the relay out to see if that makes a difference.

  7. #7
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    you may not have that relay, if you do not... then the pre-heat circuit fires off the main relay. Odd, but they ditched that relay at various points during production.

  8. #8
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    Quote Originally Posted by cartoonz View Post
    you may not have that relay, if you do not... then the pre-heat circuit fires off the main relay. Odd, but they ditched that relay at various points during production.
    I have four relays. I think one for each DME, one for EML and the one closest to teh firewall probably powers the oxygen sensors and heaters. they all seem to work fine, as taking any of them out immediately deteriorated the engine running.

    SO I am back to suspecting something wrong with the DME. this weekend I will replace its caps and solder reflow big items with heat sinks. Lets see if that does that the trick. I will update again later.

  9. #9
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    The 4 relays in the E-box are not quite as you assume. See this pic from the 91 ETM.

    Two are Main Relays and the other two are Fuel Pump Relays. If you have a 5th, it is the O2 sensor relay.
    For what its worth, I have the same O2 Sensor Heater Relay CE error on my car and i too, do not have that relay - only the early cars did. Once the CE error is cleared using the GT1, it goes away for somewhere between 8 & 10 starts of the car then reappears and will not go away until cleared. I have ruled out DME's as a possible issue by swapping in a spare set. Likewise, MAF for that side (my problem is on Bank 1 (passenger side). Error is detected during cranking at start-up. BMW DIS states that "error can be ignored if Relay is not present" - thats great but the CE light doesnt allow ignoring! 8-) Both my )2 sensors test out fine as well.
    Last edited by Wuffer; 11-24-2009 at 12:38 PM.
    91 850 (Panzer), 2012 Mini Cooper Countryman (WifeMobile) www.wuffer.ca


  10. #10
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    Quote Originally Posted by Wuffer View Post
    The 4 relays in the E-box are not quite as you assume. See this pic from the 91 ETM.

    Two are Main Relays and the other two are Fuel Pump Relays. If you have a 5th, it is the O2 sensor relay.
    For what its worth, I have the same O2 Sensor Heater Relay CE error on my car and i too, do not have that relay - only the early cars did. Once the CE error is cleared using the GT1, it goes away for somewhere between 8 & 10 starts of the car then reappears and will not go away until cleared. I have ruled out DME's as a possible issue by swapping in a spare set. Likewise, MAF for that side (my problem is on Bank 1 (passenger side). Error is detected during cranking at start-up. BMW DIS states that "error can be ignored if Relay is not present" - thats great but the CE light doesnt allow ignoring! 8-) Both my )2 sensors test out fine as well.

    An answer from the man himself. Love your site!

    Your description of the issue is exactly like mine. However this started happening when the weather got colder, and my CEl only comes on in the morning, and each morning. I reset immediately after it comes on or during the day. I am still thinking electronic parts acting up in the DME. So you say you ruled that out by swapping the DMEs. I don't think there is anything else between DME and Oxygen sensors. So the only other option is this is a symptom of some other minor issue.

  11. #11
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    I have multiple sets of spare tested DME's and EML's so I installed a complete set with no change in the problem - still happens every 8-10 starts and error is detected when the car is cranking (low RPM -something like 220 rpm iirc). I reset it yesterday and was out a few times today - temp in the low 40's F with no error - but it will be back tomorrow or the next day. Car runs fine otherwise. GT1 says my O2 sensors are acting correctly but I was going to swap out the one on the passenger side to eliminate that as an issue - but you have already done so with no change. Beyond that, dont know what else to check/replace at this time but will be spending some time reading the ETM over the next few days.

    Further info from the ETMDP Manual...Defect Code 37 - Complete ETMDP Manual is available for download on my website.

    Last edited by Wuffer; 11-24-2009 at 06:55 PM. Reason: Automerged Doublepost
    91 850 (Panzer), 2012 Mini Cooper Countryman (WifeMobile) www.wuffer.ca


  12. #12
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    Quote Originally Posted by Wuffer View Post
    GT1 says my O2 sensors are acting correctly but I was going to swap out the one on the passenger side to eliminate that as an issue - but you have already done so with no change. Beyond that, dont know what else to check/replace at this time but will be spending some time reading the ETM over the next few days.

    the circuit diagram shows the heater active without the help of the DME, and there is no connection between heater and any kind of sensor feeding back to the dme or other electronic circuit to check voltage or continuity for the dme to figure out the heater is broken. So without the relay that would have been triggered by the dme, the error we are getting is one that we should not be getting since the circuit is not there to trigger the error. There is some other connection that comes off of fuse 28, that is supposed to go to the servotronic unit for steering, which is also not installed on U.s model cars. I was trying to trace that connection to see if it ends up feeding back to the dme somehow, but the circuit diagrams don't show all these connectors. Well I'll do some more research tomorrow or over the weekend and will post again.

    but just for the record I only replaced one oxygen sensor on teh passenger side. but like I said earlier both sensor had same resistance value and both connectors had power for the heaters with the car in the on position.

    wuffer, do you have circuit diagrams for the models with a relay activated sensor heaters? We need to see how that ends up connecting to the DME.

    Thanks
    Last edited by sanid98; 11-25-2009 at 12:11 AM. Reason: Automerged Doublepost

  13. #13
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    The error comes from the O2 sensor not being up to temperature, not from the relay. That is what the DME sees. Yeah, I know that's not exactly how the book words it but that is it in practice. The DME can tell from the O2 feedaback that the sensor itself is not up to temperature. There is no separate "temperature" loop.

    On cars with the relay, the relay is driven from a pin on DME1. I recently replaced the entire engine wiring harness with one I had to completely rebuild and freaked when I went to install it and it was missing the damned relay.... I did tear into it again and splice the relay into it but later decided to remove it anyway because:

    The power that goes through that relay to the O2 sensor is already controlled by the Main Relay... so it stands to reason that is you are getting this code now with known good o2 sensors, that is the circuit you want to check.
    Last edited by cartoonz; 11-25-2009 at 01:36 AM.

  14. #14
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    Quote Originally Posted by cartoonz View Post

    The power that goes through that relay to the O2 sensor is already controlled by the Main Relay... so it stands to reason that is you are getting this code now with known good o2 sensors, that is the circuit you want to check.
    When I swapped out the passenger side oxygen sensor, I checked the voltage at the connectors in the run position, both circuits had same voltage. there may still be some intermittent problem, but even if there is, the DME has no way of knowing given the relay circuit from the DME is not there.

    the light comes on right after cranking the engine, the heaters would have no time to heat the sensors, so temperature can't be something the DME is measuring at least not initially. The sensor temperature at cranking (first few seconds is more or less a function of outside temperature).

  15. #15
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    An update - Cautiously optimistic...
    I replaced fuse #28 - old one tested ok but replaced it anyway. Also based on the input above from Cartoonz, I also replaced both Main Relays (K212 & K213) and while it has only been a day since then, so far so good, no CE light. That being said, it takes 8-10 starts for my car to exhibit the problematic CE light so will be monitoring for the next few days.
    FWIW...
    91 850 (Panzer), 2012 Mini Cooper Countryman (WifeMobile) www.wuffer.ca


  16. #16
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    Wuffer please post again in few days. I wanted to replace the caps in the dme, but will wait to hear from you first.

    Thanks.

  17. #17
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    Rermember I have already replaced both DME's without fixing the problem so I am doubtful that is what the issue is in your case. Will post again in a few....
    91 850 (Panzer), 2012 Mini Cooper Countryman (WifeMobile) www.wuffer.ca


  18. #18
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    Quote Originally Posted by Wuffer View Post
    An update - Cautiously optimistic...
    I replaced fuse #28 - old one tested ok but replaced it anyway. Also based on the input above from Cartoonz, I also replaced both Main Relays (K212 & K213) and while it has only been a day since then, so far so good, no CE light. That being said, it takes 8-10 starts for my car to exhibit the problematic CE light so will be monitoring for the next few days.
    FWIW...
    Hi wuffer, any updates did the relays do the trick?

    Thanks
    Last edited by sanid98; 12-29-2009 at 05:32 PM. Reason: Asking Wuffer to provide an update

  19. #19
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    Success i think!!!

    So few weeks back I decided to do a tune up. I started with Distributor caps and arms, then started replacing spark plugs, one of my spark plug connector was broken, but seemed to work intermitently.... or something. I replaced just the connector. I have been driving it for 2 weeks now and so far no check engine at start up. So I guess the problem is faulty ignition. If you have that problem.. start with inspecting the distributor and arm, wires connectors and spark plugs.

    Regards.

  20. #20
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    Mine was a MAF sensor.
    I rebuilt both , installed and the car has been running like a bat outta hell since (and no more CEL).
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  21. #21
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    Quote Originally Posted by TxGR8White View Post
    Mine was a MAF sensor.
    I rebuilt both , installed and the car has been running like a bat outta hell since (and no more CEL).
    Both my MAFs work fine, but I am curious what do you rebuild in a MAF, I opened one once, didn't see anything to replace

  22. #22
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    So - resurrecting this from the dead.

    I'm having the same exact issue as described by sanid and wuffer. Any new leads on this issue in the last 8 years?

    My O2 sensors have been replaced and are working, and relay's have been inspected (even replaced a few relays that looked "iffy"). CEL will stay off for a few days once cleared, but will come back on directly on a fresh cold startup a couple days after being cleared. Never comes on mid-drive.

    Stomp test always reads 1264 - "Lambda (O2) Sensor Heater."

    Thanks for any help

  23. #23
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    Did you replace 2 main DME relays and fuse #28? if not, replace and report back.

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    Will do, thanks!

  25. #25
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    Quote Originally Posted by sanid98 View Post
    the circuit diagram shows the heater active without the help of the DME, and there is no connection between heater and any kind of sensor feeding back to the dme or other electronic circuit to check voltage or continuity for the dme to figure out the heater is broken. So without the relay that would have been triggered by the dme, the error we are getting is one that we should not be getting since the circuit is not there to trigger the error. There is some other connection that comes off of fuse 28, that is supposed to go to the servotronic unit for steering, which is also not installed on U.s model cars. I was trying to trace that connection to see if it ends up feeding back to the dme somehow, but the circuit diagrams don't show all these connectors. Well I'll do some more research tomorrow or over the weekend and will post again.

    but just for the record I only replaced one oxygen sensor on teh passenger side. but like I said earlier both sensor had same resistance value and both connectors had power for the heaters with the car in the on position.

    wuffer, do you have circuit diagrams for the models with a relay activated sensor heaters? We need to see how that ends up connecting to the DME.

    Thanks
    Old thread but one thing I noticed when I was tuning my 8 was that the DME does in fact switch the heaters on and off. I know this because I thought id save myself a few minutes and power my wideband o2 gauges from the 12v heater circuit. It was fine until I pressed the pedal over a certain percentage and took the DME out of part throttle map....at that point the power would switch off and come back on as I eased off.

    Thinking about it, I'd say it was morel likely EML controlled being pedal related....I didn't look into it, I just ran another 12v feed.
    Last edited by Omega man 1969; 05-06-2018 at 05:05 AM.

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