[betoojaquezz17]

I know this is an old thread, I'm also new here.

I have an 06' E90 330i 6MT that's been throwing o2 sensor codes/ heater circuit issues . After resetting codes car will be fine until CEL comes on. Starts idling roughly, enters limp mode. Car has 158k miles so threw in all four new oxygen sensors. Code 002CA7 still persistent. After replacing B1S1 with new sensor to rule out faulty sensor, code came back after cold start and it will occasionally misfire during cold starts. I have thoroughly inspected o2 sensor wiring harness as far as removing intake and pulling wires from behind engine. Found no signs of damage, wiring is intact all the way up to dme.

Recently serviced for recall (heater elbow) in hopes it would solve heater circuit issue, it did not. I've reset adaptations using INPA, no luck.

Am I having dme issues?? I'm out of ideas.

[Wolf 335]

Originally Posted by hassmaschine

disconnecting the battery doesn't reset the computer at all. That is my point. The current "state" is always saved in non-volatile memory.

if the codes are not clearing it's because the issue is still present.

I believe he was referring to draining the electrical system.

It's not just the matter of disconnecting the battery, there is one more step involved.

You need to disconnect the battery cables and then touch the positive and negative cables together. Leave them connected for 30 mins.

Make sure you do not make contact with any terminals on the battery itself!!!

Sometimes this method does help.


OP(or anyone) if you are planning on doing this i suggest you read up on this first, i do not take any responsibility if you kill your car.

EDIT: just realized this thread is 30 years old

[gbalthrop]

Originally Posted by betoojaquezz17

...06' E90 330i 6MT that's been throwing o2 sensor codes/ heater circuit issues. [WHAT Codes are you reading?] After resetting codes car will be fine until CEL comes on. Starts idling roughly, enters limp mode. Car has 158k miles so threw in all four new oxygen sensors. Code 002CA7 still persistent. After replacing B1S1 with new sensor to rule out faulty sensor, code came back after cold start and it will occasionally misfire during cold starts. I have thoroughly inspected o2 sensor wiring harness as far as removing intake and pulling wires from behind engine. Found no signs of damage, wiring is intact all the way up to dme.
Recently serviced for recall (heater elbow) in hopes it would solve heater circuit issue, it did not. I've reset adaptations using INPA, no luck.
Am I having dme issues?? I'm out of ideas.

Here are TIS wiring diagram for O2 Sensors & Heaters, and Fuse F04 circuit which shows that fuse supplying power to ALL 4 Sensors AND the Crankcase Vent Heater; also circuit for K6300 DME relay which powers F04 & Others:
https://www.newtis.info/tisv2/a/en/e...ontrol/otwHfc8
https://www.newtis.info/tisv2/a/en/e90-330i-lim/uM1qAq9
https://www.newtis.info/tisv2/a/en/e...supply/i4RGgA7

The code you provide, "2CA7" is for Bank 2 Pre-cat Sensor heater failure (Sensor below proper operating Temp), and here is BMW Fault Code Lookup definition of 2CA7 and the Fault Information Sheet for that Fault:
N52 | P0059 | 2CA7 | DME: Oxygen sensor heater 2 before catalytic converter: Function | MSV70
http://www.bmwfault.codes/XMLDiagVie...gAMQA1ADAANAA=

I would suggest starting over as if you were FIRST beginning to test for cause of fault. Fuse F04 is powered by the DME Relay, K6300, meaning it should have power when ignition ON. Check for 12V+ at F04 socket in E-box and at O2 Sensor Orange wires, Pins #4 of Pre-cat sensors, and #1 of Post-cat sensors. If Power Supply to Bank 2 Pre-cat sensor (at Pin #4 of Connector X62201) is OK, check for ground at pin #3, White/Blue wire, provided by DME on Cold Start. There HAS to be a wiring or Power supply issue (INCLUDING switched-ground to heaters provided by DME). Here is TIS "Connector View" of the Pre-cat O2 Sensor Connectors:
https://www.newtis.info/tisv2/a/en/e...62201/CT6giy7l

Please let us know what you find,
George

[betoojaquezz17]

Thanks for replying, will try to restart the diagnostic as you said, as soon as I put intake and wiring back in! Will update.

[BashShah]

Msd80 to msd81 upgrade.
Or dme mosfet repair.

[edirty9_]

Was it the mosfet that caused this? Or a smaller blown resistor? I pinched my O2 doing a manual swap and now have this code. At first it was blowing the 30 amp fuse in the ecu box. But after replacement of sensor I only have the 2c3f code

[BashShah]

Originally Posted by edirty9_

Was it the mosfet that caused this? Or a smaller blown resistor? I pinched my O2 doing a manual swap and now have this code. At first it was blowing the 30 amp fuse in the ecu box. But after replacement of sensor I only have the 2c3f code

Not sure in my case what caused it.
Dealer stated a Resister.
Never Diagnosed it to see if it was a Resister on one of the PINs.
Continuity test is BULLSH&^T, cause quite a few wire harness pin on the DME lead to multiple points on the other end.

I went through Guillermo in Houma, Louisianan.
Send him you CAS Module and working Key.
He had it back to me the next day.

so basically it was cheaper to change my DME from MSD80 to used MDS81 through Guillermo. cost was under 500 for me, very much under 500.
He is a super nice guy.

There is a MOSFET Repair procedure also, but I was not sure if that would solve my problem, but I think mine was a resister issue were the wires shorted and burned a resister.

Dealership had a Machine that they put inline between DME and Vehicle and within 2 min it pointed out which pin on the DME was shorted.
I am pretty sure no Indy shop would have that machine.

Good luck.