Chevy Cobalt Forum banner

Status
Not open for further replies.
1 - 2 of 2 Posts

·
Registered
Joined
·
141 Posts
Discussion Starter #1 (Edited)
P0420

just got this code any1 know what i can do to fix it
 

·
Wootsauce!
Joined
·
8,593 Posts
P0040 Upstream Oxygen Sensors Swapped From Bank To Bank

---------- Post added at 10:03 PM ---------- Previous post was at 10:03 PM ----------

Still searching...

---------- Post added at 10:08 PM ---------- Previous post was at 10:03 PM ----------

P0040 - Check Engine Light Diagnostic Trouble Code Description

Description:

How does a P0040 code trigger the check engine light? This code will trigger the light to come on under the following condition:

The Heated Oxygen Sensor Monitor, a strategy built into the computer, determines if the Heated Oxygen Sensor (HO2S) signal response for a change in fuel trim corresponds to the correct engine bank. If a response from the Oxygen Sensor being tested is not indicated, a trouble code will be set and the MIL (Malfunction Indicator Lamp) will illuminate.
Possible Causes:

Crossed Heated Oxygen Sensor harness connectors
Wiring swapped from one Oxygen Sensor connector to the other
Wiring changed at the computer connection or in the related harness
Diagnostic Help:

This check engine light code is caused by swapped wiring or connectors of the upstream Heated Oxygen Sensors. This would have to be the result of a previous repair, so be sure to check the vehicle history. You may also use the "Get Help" link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific
 
1 - 2 of 2 Posts
Status
Not open for further replies.
Top