sbwrench

iTrader: (19)

Hello,

E38 pcm running a 2015 LS3 in a Miata. Using Z06 air intake with ls2/ls3 card style maf with iat built in. The pcm is the one that came with the engine. OS and calibration details all confirm this. Scanner reads -40 for intake air temp. Getting a po113 code.

Things I have done: substituted new GM Maf sensor, substituted known good e38, pinned all 5 wires from maf back to pcm. All have continuity and all go to the proper pins based on 2015 Camaro pin out for e38. Checked resistance on pin E on maf (iat signal) and it showed proper resistance for the current ambient temp.

My last check will be to see is resistance values are correct at pcm side of iat signal wire. What am I missing? Thanks for any help. BTW, this is about conversion number 30, so I have a lot of diagnostics practice.

minytrker

iTrader: (13)

If you have checked all those things correctly then its bad ECM.

sbwrench

iTrader: (19)

Substituted another E38 pcm with my standard ls3 crate engine base map. Same. Same.

minytrker

iTrader: (13)

The IAT part of the MAF is only 2 wires, so you either have something wrong with one or both of the two wires, bad maf or bad ecm. That's every part to the IAT circuit.

sbwrench

iTrader: (19)

That's what I know! That's what is baffling me. I'm going to re run some earlier tests and make sure I didn't look past something.

sbwrench

iTrader: (19)

Fixed. Ordered yet another maf/iat sensor as everything had checked out. Third one was the charm! So the take away, as we all know, just because it is new out of the box, doesn't mean it's good. Thanks for the help.

minytrker

iTrader: (13)

Unfortunately that is happening more and more often now days. We just changed out a brand new maf 2 weeks ago.