ecu / downstream oxygen sensor problem - Suzuki Forums: Suzuki Forum Site
Suzuki Forum Suzuki Forums

» Auto Insurance
» Featured Product
Wheel & Tire Center

Go Back   Suzuki Forums: Suzuki Forum Site > Suzuki Models > Other Suzuki Models > Suzuki SX4 Forum
Register Home Forum Active Topics Photo Gallery Garage Today's Posts Auto EscrowAuto LoansInsurance Advertise

Suzuki-Forums.com is the premier Suzuki All Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 05-04-2016, 11:57 AM   #1 (permalink)
Newbie
 
Join Date: May 2016
Location: Langley, BC
Posts: 16
Gallery: 0
zabicki is on a distinguished road
Default ecu / downstream oxygen sensor problem

Hi there,

I have a problem with the downstream oxygen sensor and the ecu

I got check engine light with p0138 error code.
I scanned the scar and noticed that the voltage on the downstream oxygen sensor is constant 1.3 volts. The sensor was removed from the car and tested with a torch and a multi-meter Technically seems to work ok.
However there is something weird. I scanned the car without the sensor connected and the voltage stays the same - 1.3 volts on the ecu.

I also scanned the voltage on the o2 plug coming to the ecu.
I got 12v on the heater wires and 4.35 volts coming down to the oxygen sensor (from ecu) (positive and ground wires).

Can you please help me to diagnose what's going on ?
zabicki is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 05-04-2016, 02:22 PM   #2 (permalink)
Veteran
 
aquanaut20's Avatar
 
Join Date: Oct 2007
Location: FraserValley, BC, Canada
Posts: 8,146
Gallery: 0
aquanaut20 is on a distinguished road
Default

Check for shorted wires, common to hot pipes, and frame scuffing..

... Philip
__________________
.... Philip

92 Ford Explorer, 450k
97 Ford Explorer, 400k
99 Tracker, 4dr, 4x4, 2L DOHC, auto 265k
aquanaut20 is online now   Reply With Quote Quick reply to this message
Old 05-04-2016, 03:52 PM   #3 (permalink)
LMP
Veteran
 
LMP's Avatar
 
Join Date: Oct 2011
Location: Chicoutimi, Saguenay,Qc,Canada
Posts: 803
Gallery: 1
LMP is on a distinguished road
Default

Quote:
Originally Posted by zabicki View Post
...I got 12v on the heater wires and 4.35 volts coming down to the oxygen sensor (from ecu) ....
Both voltages OK. 4.35 open Volts from ECU is normal.
Welcome to the forum. In order to know you more, please fill up your profile, where are you, car type, year, AWD?..transmisison..etc. ...
__________________
2011 sx4 JX 2.0 AWD CVT at 35500km(may2019)- 1928 Model 629 Graham-Paige - 1993 Pontiac Transport 3.8 - 2015 Kia Sorrento 2.4 AWD - 1994 Kawasaki Ninja EX250
LMP is offline   Reply With Quote Quick reply to this message
 
Old 05-04-2016, 04:51 PM   #4 (permalink)
Newbie
 
Join Date: May 2016
Location: Langley, BC
Posts: 16
Gallery: 0
zabicki is on a distinguished road
Default

Oh you got me 2008 SX4 AWD automatic. Regarding the voltage - why my android scanner shows 1.3V for that o2 sensor? Shouldn't be 0V when disconnected?

Technically the scanner shows 1.3v either connected or disconnected and pops up with p0138 code...
zabicki is offline   Reply With Quote Quick reply to this message
Old 05-04-2016, 05:48 PM   #5 (permalink)
Veteran
 
aquanaut20's Avatar
 
Join Date: Oct 2007
Location: FraserValley, BC, Canada
Posts: 8,146
Gallery: 0
aquanaut20 is on a distinguished road
Default

http://www.obd-codes.com/p0138
__________________
.... Philip

92 Ford Explorer, 450k
97 Ford Explorer, 400k
99 Tracker, 4dr, 4x4, 2L DOHC, auto 265k
aquanaut20 is online now   Reply With Quote Quick reply to this message
Old 05-04-2016, 05:59 PM   #6 (permalink)
Newbie
 
Join Date: May 2016
Location: Langley, BC
Posts: 16
Gallery: 0
zabicki is on a distinguished road
Default

I know what that code means. The problem is that I see that code even though the sensor is disconnected...
zabicki is offline   Reply With Quote Quick reply to this message
Old 05-04-2016, 06:39 PM   #7 (permalink)
Newbie
 
Join Date: May 2016
Location: Langley, BC
Posts: 16
Gallery: 0
zabicki is on a distinguished road
Default

unless there is an open circuit and 1.3v means that the sensor is broken.
Is there anyone how could check that on their car? like unplugging the downstream sensor and checking what voltage appears one the scanner .. I know it's a lot to ask for.
zabicki is offline   Reply With Quote Quick reply to this message
Old 05-04-2016, 07:20 PM   #8 (permalink)
Veteran
 
aquanaut20's Avatar
 
Join Date: Oct 2007
Location: FraserValley, BC, Canada
Posts: 8,146
Gallery: 0
aquanaut20 is on a distinguished road
Default

Why dont you verify the circuit?

Unplug at ECU and check for voltage drop/ground/shorts.. If the circuit proves viable.. all is left is the sensor..

As an after though, what are the Fuel trims and the B1S1...

... Philip
__________________
.... Philip

92 Ford Explorer, 450k
97 Ford Explorer, 400k
99 Tracker, 4dr, 4x4, 2L DOHC, auto 265k
aquanaut20 is online now   Reply With Quote Quick reply to this message
Old 05-04-2016, 10:46 PM   #9 (permalink)
Newbie
 
Join Date: May 2016
Location: Langley, BC
Posts: 16
Gallery: 0
zabicki is on a distinguished road
Default

How can I check the wires for shorts. You mean the hot (positive) one with both heater wires and the ground (negative) with the hot (positive) right?
I suspect that the wires are ok - already getting 12v on the heater wires and ~5v on the hot and ground (negative) wires. if there was a broken wire I couldn't get the right voltage on the plug coming from the ecu

The A/F sensor is brand new.
zabicki is offline   Reply With Quote Quick reply to this message
Old 05-05-2016, 01:16 AM   #10 (permalink)
Veteran
 
aquanaut20's Avatar
 
Join Date: Oct 2007
Location: FraserValley, BC, Canada
Posts: 8,146
Gallery: 0
aquanaut20 is on a distinguished road
Default

I suggested in post 8, do you not understand how to verify the circuits, or do you wish to keep guessing?

If you unplug from ECU (power OFF)they should all be open, no shorts to ground, when tested from sensor plug.

Baring that, employ an auto electrician...

... Philip
__________________
.... Philip

92 Ford Explorer, 450k
97 Ford Explorer, 400k
99 Tracker, 4dr, 4x4, 2L DOHC, auto 265k

Last edited by aquanaut20; 05-05-2016 at 01:20 AM.
aquanaut20 is online now   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

  Suzuki Forums: Suzuki Forum Site > Suzuki Models > Other Suzuki Models > Suzuki SX4 Forum

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Suzuki Forums: Suzuki Forum Site forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:41 PM.



Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.