Post Reply 
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
04 Chevy Tahoe 5.3L 4-wire O2 sensors
Author Message
romulus Offline
Member
***

Posts: 24
Joined: Jun 2008
Reputation: 0
Post: #1
04 Chevy Tahoe 5.3L 4-wire O2 sensors
    Got word my duel EFIE shipped today, thanks Mike. I didnt know if anyone has worked with a Tahoe before and could save me frustration in making a mistake hooking up the EFIE. I have 2 O2 sensors with 4 wires each, Blue, White and 2 Blacks. I went to id my signal wire and could use help from someone to validate that I have the right signal wire. 1 Black wire definately shows 12v with key on. One black wire shows 0v. The Blue and White wires are the question. I cant seem to get a definate reading on these wires. I am not sure if my ground is good because the numbers jump around with key on but one definatly jumps around more then the other. I have attached wiring diagram for my truck. Note: the blue wire from the O2 comes out of the harness as a Purple wire w white strip to the ECU. The white wire = Tan wire to ECU, Black = Pink to ECU and other Black = Black to ECU. This will make more sense when you see the diagram. Thanks
07-13-2008 06:01 PM
Find all posts by this user Quote this message in a reply
colchiro Offline
Moderator
*****

Posts: 3,265
Joined: Feb 2008
Reputation: 11
Post: #2
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
The one that jumps the most is the one you want. Does it vary between 0 and 1 volts when measured against ground?

I'm concerned because you said you have a blue wire, usually indicating an air-fuel sensor.

Rick

Links: Documents / Tuning for Mileage | Toyota Sensors | Autoshop Sensor Tutorials
07-13-2008 06:15 PM
Find all posts by this user Quote this message in a reply
romulus Offline
Member
***

Posts: 24
Joined: Jun 2008
Reputation: 0
Post: #3
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
colchiro Wrote:The one that jumps the most is the one you want. Does it vary between 0 and 1 volts when measured against ground?

I'm concerned because you said you have a blue wire, usually indicating an air-fuel sensor.

Yes the blue wire does jump around the most between 0 and 1 volt while running but again not real confident on the test. The white wire seems to stay around .4 volts. If you look at the diagram you will see that the Blue wire (purple white strip) is the HIGH SIGNAL wire. The other wire is the LOW REFERENCE wire. Not sure what that means so I asked the question. It also calls it a Heated O2 Sensor.
07-14-2008 02:59 AM
Find all posts by this user Quote this message in a reply
rpatzer Offline
Member
***

Posts: 348
Joined: Apr 2008
Reputation: 0
Post: #4
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
romulus Wrote:
colchiro Wrote:The one that jumps the most is the one you want. Does it vary between 0 and 1 volts when measured against ground?

I'm concerned because you said you have a blue wire, usually indicating an air-fuel sensor.

Yes the blue wire does jump around the most between 0 and 1 volt while running but again not real confident on the test. The white wire seems to stay around .4 volts. If you look at the diagram you will see that the Blue wire (purple white strip) is the HIGH SIGNAL wire. The other wire is the LOW REFERENCE wire. Not sure what that means so I asked the question. It also calls it a Heated O2 Sensor.

You could call the manufacturer of your O2 sensor and have them tell you which wire to use for the AFR meter you want to instal. That is the wire you want.
07-14-2008 06:10 AM
Find all posts by this user Quote this message in a reply
romulus Offline
Member
***

Posts: 24
Joined: Jun 2008
Reputation: 0
Post: #5
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
Went to chevy today and both mechanics I talked with both said the blue wire is the signal wire. Note for everyone. they told me to be sure to soider and shrink wrap any connection I make under the car because the corrosion will follow the wire back to the ECU...Thank Aint good. FYI
07-14-2008 06:20 AM
Find all posts by this user Quote this message in a reply
colchiro Offline
Moderator
*****

Posts: 3,265
Joined: Feb 2008
Reputation: 11
Post: #6
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
... and the blue wire is the sense wire on my air-fuel sensor. (I still think that's what you have.)

If you tap into the wire attached to the sensor, you don't need to worry about that.

They're just scaring you b/c they don't want you to mess with their stuff.

Rick

Links: Documents / Tuning for Mileage | Toyota Sensors | Autoshop Sensor Tutorials
(This post was last modified: 07-14-2008 07:31 AM by colchiro.)
07-14-2008 07:30 AM
Find all posts by this user Quote this message in a reply
romulus Offline
Member
***

Posts: 24
Joined: Jun 2008
Reputation: 0
Post: #7
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
If I install my EFIE to the blue wire and it is an A/F sensor what will happen when I try to tune it?
07-14-2008 09:33 AM
Find all posts by this user Quote this message in a reply
colchiro Offline
Moderator
*****

Posts: 3,265
Joined: Feb 2008
Reputation: 11
Post: #8
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
romulus Wrote:If I install my EFIE to the blue wire and it is an A/F sensor what will happen when I try to tune it?

If it's like my Toyota, no matter how you hook it up, you'll only be able to go richer, not leaner.

You could try hooking up the EFIE backwards and see what it does. Might as well try it since you have it installed.

Rick

Links: Documents / Tuning for Mileage | Toyota Sensors | Autoshop Sensor Tutorials
07-14-2008 05:59 PM
Find all posts by this user Quote this message in a reply
romulus Offline
Member
***

Posts: 24
Joined: Jun 2008
Reputation: 0
Post: #9
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
colchiro Wrote:
romulus Wrote:If I install my EFIE to the blue wire and it is an A/F sensor what will happen when I try to tune it?

If it's like my Toyota, no matter how you hook it up, you'll only be able to go richer, not leaner.

You could try hooking up the EFIE backwards and see what it does. Might as well try it since you have it installed.
I just read the white label on the hood of my car ( both my Tahoe and Sonata) labeled emissions control. On that label it states SFI/HO2/TWC. According to an emailer that this lists what type of sensor the car has. I am assuming that the HO2 means heated oxygen sensors. Colchiro, what does the label on your Toyota say? I am curious to see if your label reads that it is an AF.......May help alot of people answer the "what type of sensor" question.
07-18-2008 12:03 PM
Find all posts by this user Quote this message in a reply
colchiro Offline
Moderator
*****

Posts: 3,265
Joined: Feb 2008
Reputation: 11
Post: #10
RE: 04 Chevy Tahoe 5.3L 4-wire O2 sensors
Mine says A/F sensor..... HO2S

I believe my post cat sensors are o2 sensor (narrow band).

Rick

Links: Documents / Tuning for Mileage | Toyota Sensors | Autoshop Sensor Tutorials
(This post was last modified: 07-18-2008 05:20 PM by colchiro.)
07-18-2008 05:20 PM
Find all posts by this user Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)