P0140 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


OBD-II Trouble Shooting Got a code reader? Find out what your GM car's Check Engine light is trying to tell you (and then turn Check Engine light off).

 
 
 
 
Thread Tools Search this Thread
Old 09-24-2009, 11:13 AM   #1
Retired Senior Admin

Expert Gearhead
Thread Starter
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default P0140

P0140

Description
HO2S 2 INSUFFICIENT ACTIVITY


Three-Way Catalyst (TWC) system is used to control emissions.
PCM uses signal from Heated Oxygen Sensor (HO2S) behind TWC to read
efficiency of TWC. PCM will set DTC P0140 if TWC oxygen storage
capacity is less than a predetermined threshold.

Symptoms
Your Service engine light(SES), or malfuction indicator lamp (MIL) will be illuminated. There will not likely be any noticeable drivability problems other than the MIL. The rear or post catalytic converter Oxygen sensor does not affect fuel deliver It only MONITORS the efficiency of the catalytic converter.

Causes
  • Shorted heater circuit in O2 sensor.
  • Shorted signal circuit in O2 sensor
  • Melting of harness connector or wiring due to touching the exhaust system
  • Water in harness connector or PCM connector
  • Bad PCM
Possible Solutions
Typically, simply changing the rear O2 sensor corrects the problem. Before doing this inspect the wires and connectors for damage or corrosion.
Danthurs is offline  
 
 
 

Related Topics
Thread Thread Starter Forum Replies Last Post
P0140 Galvez83 2000-2005 1 03-21-2008 03:12 PM


Tags
obd2, obdii, p0140, p140

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:23 AM.


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.