Notices
PCM Diagnostics & Tuning HP Tuners | Diablo | Pantera EFI

P0102 MAF Signal and Voltage, Signal 9V ?!

 
Old 12-30-2018, 04:42 PM
  #1  
Teching In
Thread Starter
 
Join Date: Nov 2018
Location: Austin, TX
Posts: 24
Default P0102 MAF Signal and Voltage, Signal 9V ?!

I have one CEL on my 2002 C5Z and I'm having a hard time. P0102 for MAF Signal.

I tested the Voltage and checked ground resistance. The MAF Signal voltage is off, reading high. Here are the results

Pink: 12v
Yellow: 9v-10v
Black: 0v, with .01 Ohms to ground

Purple: 2v
Orange: .02v

The yellow signal wire is supposed to see 5v and is consistently reading 9v. This is of course the issue, but I can't see any issues in the harness. The car does have a mail order tune/pcm but it's from the previous owner and I have no idea what's on it.

When I clear the code while running, the car dies. It cranks once and shuts off, then runs on next start. It will drive one cycle without CEL, then next startup throws CEL for P0102. While CEL is off it shows a Current P0102 but doesnt go Hard until next start. Car runs fine afterwards, I'm just trying to get it registered and inspected and need to resolve the CEL.

What would cause HIGH MAF Signal Voltage? Wrong MAF? Bad MAF? Short to 12v signal (doubtful since other sensors read fine, also tested with no continuity between)? Speed density tune?

Can someone point me in the right direction?

Last edited by mattdev10; 12-30-2018 at 05:11 PM.
mattdev10 is offline  
Old 12-30-2018, 05:36 PM
  #2  
Teching In
Thread Starter
 
Join Date: Nov 2018
Location: Austin, TX
Posts: 24
Default

So far I'm thinking new China MAF for $30, it's worth a shot. (I'll return it if it doesn't fix).
mattdev10 is offline  
Old 12-30-2018, 06:10 PM
  #3  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 9,480
Default

Sounds like you and I suspect the same thing. On the other thread you posted on, I posted asking if maybe both you guys' MAF's were bad or very dirty. I guess we will soon see! lol
G Atsma is online now  
Old 01-05-2019, 08:42 PM
  #4  
Teching In
Thread Starter
 
Join Date: Nov 2018
Location: Austin, TX
Posts: 24
Default

New MAF FIXED, no CEL after a couple drive cycles. MAF was $25 BNIB on eBay...
mattdev10 is offline  
Old 01-09-2019, 09:42 PM
  #5  
Teching In
Thread Starter
 
Join Date: Nov 2018
Location: Austin, TX
Posts: 24
Default

Update:
No code with new MAF but the engine stumbles around 5000rpm and wont rev past under WOT. Unplugged the MAF and revs out all the way. I'm guessing its the china maf being from china...
guess I'll replace with OEM and post an update.
mattdev10 is offline  
Old 01-21-2019, 07:41 PM
  #6  
Teching In
Thread Starter
 
Join Date: Nov 2018
Location: Austin, TX
Posts: 24
Default

Update:
New OEM ACDelco MAF (LS6 PN) was pricey at $150 but it's solved now.
mattdev10 is offline  
 


Thread Tools
Search this Thread

About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: