Help with High idle issue and CEL codes

[nsfwaldo]

Hey guys! This is my first XC70 that I've owned but my third volvo so far. I just had the CEL come on for the first time the other day. I have a VIDA reader and I got codes:

ECM-120C Air mass signal -- too high (P0100 OBD code)
ECM-951C Engine control module (ECM), idle control -- Signal too high (P0507 OBD code)

symptoms are a high idle in park and neutral (obviously) and it just started randomly with nothing clear to cause it that I recall

Any ideas what's causing these two codes? Is my MAF shot already? I just cleaned it with MAF cleaner last night to see if it would change anything to no avail. I also noticed while trying to check for vacuum leaks and whatnot that my upper PCV hose/pipe is cracked in a few places. New hose on the way for that. Is my whole PCV system shot and causing the problems?

Any help is appreciated! Thank you!

[nsfwaldo]

Here's a pic for visual aesthetics :D

7977

[hoonk]

ECM-120C Air mass signal -- too high (P0100 OBD code)
ECM-951C Engine control module (ECM), idle control -- Signal too high (P0507 OBD code)

Any ideas what's causing these two codes?

If you have a copy of Vida - click on fault tracing, then diagnostic trouble codes and associated procedures. Find your codes in the list and try what Vida recommends.

A dirty throttle could cause an erratic idle, and that is one of the possibilities listed for air mass codes.

[Xfingers]

What model year and how many miles? If you're over 100k and you want to keep the car for a while, a PCV replacement is probably in your near future. Not to say that this is the cause for your CELs. When the PCV system becomes clogged with oil deposits, you won't necessarily get a code but the blockage will build pressure in the crankcase and blow out your oil seals. This can result in RAPID oil loss!

[Astro14]

Upper PCV hose crack = vacuum leak.

As was said - do the whole system. The parts don't age well and you're best off to simply replace all of the PCV parts with new ones. Get a kit like the one from IPD. Fixing the vacuum leak will certainly help your idle issues.