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.

 

The very first thing I'd do is check the battery. Jags do not like low voltage and if the voltage drops just a little below 12.5 Volts, it'll start throwing every code in the book.


Mark

 

Not likely to be a bad module. +1 battery is suspect but do the same codes keep coming straight back or what?

Also, if XJ8 then wrong forum.....

 

Thanks guys, seems it was the battery. And, am learning my way around here, as well as the type of cat that I own.