General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds
Sponsored by:
Sponsored by: CARiD

Code P0042

Thread Tools
 
Search this Thread
 
Old Feb 8, 2008 | 01:57 AM
  #1  
Mitchell22's Avatar
Thread Starter
Registered User
 
Joined: Sep 2007
Posts: 6
Likes: 0
Default Code P0042

Hello, I need advice on what to look for that code on a 93 Firebird V6 3.4L

Car takes 20L to do 100km ...
Sometimes when idleing, RPM jumps from 400 to 900...
DTC code P0042

Thank you
Reply
Old Feb 8, 2008 | 10:06 AM
  #2  
BadBlue02SS's Avatar
Teching In
 
Joined: Feb 2007
Posts: 7
Likes: 0
Default

oxygen sensor?
Reply
Old Feb 8, 2008 | 01:41 PM
  #3  
Mitchell22's Avatar
Thread Starter
Registered User
 
Joined: Sep 2007
Posts: 6
Likes: 0
Default

Im not sure on the Computer O2 Sensor says input jumping from 75 to 500. Don't know if it's good.

When reading codes, it said P0042 Ignition System
and on internet I get this :
P0042 H02S heater control circuit (Bank 1 sensor 3)

Wich one is the good one ?

Thank
Reply
Old Feb 8, 2008 | 02:03 PM
  #4  
Mitchell22's Avatar
Thread Starter
Registered User
 
Joined: Sep 2007
Posts: 6
Likes: 0
Default

My friend says this code for that model indicate the car is running in System D wich is like "emergency ride". He says it runs Lean, and a ground is faulty somewhere. Probably the Ignition switch ground since the code reads it.

Anyone whos where its located ? The Ignition switch's ground on a 3.4 1993 Firebird V6

Ty
Reply
Old Feb 8, 2008 | 02:39 PM
  #5  
2001NBMZ28's Avatar
TECH Senior Member
 
Joined: Dec 2001
Posts: 5,398
Likes: 3
From: Jacksonville, FL
Default

On shoebox's obdI code list 42 is "Ignition Control (IC) Circuit (shorted or grounded circuit)" If you haven't already I'd check for a blown fuse somewhere, might help you nail down the circuit at least. 02 sensors are usually numbered from front to back standing at the radiator looking back, so my guess is if you have 3 it would be the one furthest back. Couldn't find a 3.4 diagnostic chart for codes, but there's got to be one out there somewhere. Sorry not much help....could be the ICM itself or just a wiring issue.
Reply
Old Feb 8, 2008 | 03:03 PM
  #6  
Mitchell22's Avatar
Thread Starter
Registered User
 
Joined: Sep 2007
Posts: 6
Likes: 0
Default

Well since this code started to appear after I installed an Alcoolmeter (yeah I know im dumb ok no more joke : ) ). I think they missed a wire or something like that. Gotta check their wiring but since I can't play with it I'll call them on monday.

I have 2 O2 Sensor both seem to be ok. jumping from 75 to around 400~500 as the computer reads them.

Do you know where the PCM is located ?
Thank

EDIT ::
Fuse in Door seems to be ok,

Last edited by Mitchell22; Feb 8, 2008 at 03:22 PM.
Reply
Old Feb 14, 2008 | 10:48 PM
  #7  
Mitchell22's Avatar
Thread Starter
Registered User
 
Joined: Sep 2007
Posts: 6
Likes: 0
Default

Hi guys,

can anyone tell me what is the grey wire on the ignition coil's plug (the largest one with the white tachometer wire) is used for ?

The guys at the garage plugged something on it, I think they wanted the tachometer and if Im right the good wire would be the white one. I think this one is used for ignition firing control.... Am I wrong ?

Firebird 1993 V6 Manual 3.4L
Grey wire on the ignition control plug on the coils.

Thank
Reply




All times are GMT -5. The time now is 12:48 PM.

story-0
10 Reasons Daily Driving a Swap Project SUCKS! (& 1 Reason to Do It Anyway)

Slideshow: 10 reasons daily-driving a swap project might not be for you. Or is it?

By Michael S. Palmer | 2026-06-17 09:39:05


VIEW MORE
story-1
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-2
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-06-18 10:26:23


VIEW MORE
story-3
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-4
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-5
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-6
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-7
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-8
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-9
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE