Greetings all. I'm a new owner of an 02 XJ8 with 88k on the clock. Purchased from a dealer I know reasonably well, free of any codes two weeks ago upon purchase. Ten days ago, ran it for a few minutes after changing air filter and neglected to reattach connector to MAF sensor. Went into protection/fail/safe mode, I scanned it, immediately leading me back to MAF. Reset, only thing remaining was a P1000. Not sure if it was immediate after (I don't believe it was), but within a few days I got a check engine light, code indicated a small emissions leak. Drove it a few days and brought it to my ace BMW mechanic. This a.m. he calls me, said he did all the tests on it, i.e. running at x rpm, etc. and got a ton of codes and that it went to fail safe, apparently simply while taking it through the tests.

Codes he got were
P0442, P1642, P1000, P1638, P1637, P1643.
His initial thought is that the ECU is bad. I've searched this board and can only determine that the 1600 codes are CAN codes and the test for resistance on CAN wires and to check connections. He's checked the intake manifold for leaks to no avail.
Any thoughts? I suggested I put this up here before he goes much further on attempting to diagnose. Thank you.

 

It sounds like a CAN system problem between the tranny and the ECM for those P16 codes and the P0442 sounds like the canister purge valve for the EVAP system is not functioning. Both of these problems are not unheard of. Maybe someone else will chime in that has personal experience.

 

Search and read about P1000 and P1111

Do those other ones keep coming back and if so which is first?

 

Have the battery load tested. A lot of strange codes can display if the voltage is a little low. A battery may appear good, and start the car, but if the voltage drop while starting is too great the modules will be affected.

 

Thanks guys, my friend and mechanic put it on the charger after reseting it and she's remained free of codes. He didn't give me voltage but said it was a little low.

 

So I picked the car up, drove her about an hour and then dummy light came back on. Throwing 0442, small emissions leak - the original code it displayed and also P1638 and 1642. Any thoughts as to two new ones? Thanks

 

Worth downloading the free JTIS and look them up as it gives the meaning AND all the known causes for each code.