what are the list of causes of the computer going into limp home an obd2 e36?

took the m3 out for a shakedown autocross today after getting the aluminum motor put in (motor has some minor stuff) and all the other weight saving goodies bolted in. motor ran like a champ and with aa headers felt as strong as the 3.2 that went out.

on about 2/3 of the passes (we ran 10 passes), in this exact place on the course near the end (a high speed right into an abrubt left-right-left transistion - very abrupt and on the brink of two wheeling) every single run the car would go into limp home mode until the end of the course. cycle the key, and all was back to normal.

i'm going to go through the wiring to check things out. something is intermittent and wonky.my 3.5" maf connector is clocked towards the shock tower and should probably be clocked at 6' oclock. i'll go through the rest of the connections to make sure they have enough slack between the motor and chassis also - just wanted to see if there was something to target.

thanks in advance.

pull codes?


what are the list of causes of the computer going into limp home an obd2 e36?

took the m3 out for a shakedown autocross today after getting the aluminum motor put in (motor has some minor stuff) and all the other weight saving goodies bolted in. motor ran like a champ and with aa headers felt as strong as the 3.2 that went out.

on about 2/3 of the passes (we ran 10 passes), in this exact place on the course near the end (a high speed right into an abrubt left-right-left transistion - very abrupt and on the brink of two wheeling) every single run the car would go into limp home mode until the end of the course. cycle the key, and all was back to normal.

i'm going to go through the wiring to check things out. something is intermittent and wonky.my 3.5" maf connector is clocked towards the shock tower and should probably be clocked at 6' oclock. i'll go through the rest of the connections to make sure they have enough slack between the motor and chassis also - just wanted to see if there was something to target.

thanks in advance.

that's next (tomorrow). left my pc with that stuff at work. i had the o2 banks backwards for a few miles and it ran like crap partial throttle. after confirmation from john doby, i flipped the connectors and it ran great since. it was only in this one turn where it would do it, so i'm not sure how i'm going to try to repro this after going through it...

It doesn't sound like the speed sensor in the diff is burned up (or you'd be in limp mode 100% of the time), but perhaps it has a bad connection that comes loose under certain G-loads?

if the HFM is bad the ecu will go into default mode. happened to me once, the hfm connection was dirty and the car wouldnt give me more than half throttle before it would cut out.

Little late to this party but...

When my cam position sensor went out, the car went into a limp home mode. I'm sure you've probably had a chance to pull codes by now, so I'm curious as to what it was.

fuel level sender went wonky. p1250 - fuel level too low to run monitor.

the air injection sims were were not working all the time due to a flakey power connection and due to the connection occasionally would power cycle during running, throwing a slew of 02 sensor codes on both banks with an associated secondary air injector error. but that didn't cause the limp home. any case, fixed that by soldering