Hi guys,

I recently purchased an '02 R53 that needed some love...it had an issue where it was going into limp mode. I did the usual - look at the codes (manifold air pressure, throttle control) and since I have a bunch of r53s and spare parts I did the quick and dirty replace this and that until I'd replaced almost every this and that on the thing! When that didn't work I started actually trying to troubleshoot... :-(

I see in my code reader that key on/engine off (or with the car running, actually) MAP is showing 0. I check the sensors (which I'd already swapped out from a running car, anyway) and I see power, ground, and signal voltage coming out of them. But then I'm stuck. I try looking in Bentley and seeing the location of the wires in the ECU plug but I get nothing when I check for continuity - and I've done the same on a working car and also get nothing, so clearly I'm doing something wrong.

What is my next step in troubleshooting this? The car has and has had other electrical issues - right now the battery will die in a couple days if left attached and the seat belt light in the dash stays on even with the car off...so probably more than just this MAP thing is wrong.

Thanks!

 

Slight update...pulled the cover off the ECU plug and was able to see I was looking at the pins wrong - was able to verify continuity from the MAP sensor trigger wires to the ECU.

So what, do I need a new ECU?

 

you do know that there are two map sensors on an "S", right?

My 06 "S" went into limp mode at times....the code kept saying faulty MAP sensor, or out of range.....turns out I was trying to diagnose the wrong MAP sensor.....my problem was the T-MAP sensor...I replaced that one and all is well again

Bryan