OBD II codes and oxygen sensors...

[bubbagumper6]

So my check engine light came on again today. I grabbed my OBD II reader and got the code which was P0036. As far as I can tell that's a generic code for "HO2S Heater Control Circuit (Bank 1 Sensor 2)" which I believe is the downstream oxygen sensor...That sensor is only a year old, I replaced it last spring when I fixed my exhaust so how could it be bad already??? Unless the code means something else?

[sacsking916]

What kind of car? Bank 1 is usually upstream. The o2 sensor upstream is the one that usually goes bad.

[bubbagumper6]

2004 Hyundai Accent

Some forum post (on a different forum I found with google) said that sensor was the downstream one, I have no idea if it is or not...

[Slayerx]

First things I would do:
Check the wiring to/from the sensor.
If you have a manual it should tell you how to actually check the sensor to see if it is what is actually wrong.

[Imtjnotu]

was it the splice in sensor or the plug and play?

[bubbagumper6]

was it the splice in sensor or the plug and play?

Directly plugged in, no splicing required.

[mikelaubach]

Bank indicates left or right on a multi-bank engine (v6, v8). Sensor 1 and sensor 2 indicate upstream (s1) and downstream (s2) of the cat.

My experience with our Audi A4 is that S2 are the ones constantly going out, not sensor 1. My bronco is rock solid in that regard. <knocking on wood>

Also, note your error - it is NOT saying that the sensor is bad, it is indicating that the heater in the sensor is bad. While a technicality, and fewking monkey spanker will be along to call me on it, it is not the sensing portion, but the part that heats up the sensing portion. This heating up allows the sensor to trigger faster (as compared to waiting until the sensor heats up via the passing exhaust gases). As noted above, the first real step is to check the heater portion and associated wiring. There could be a cut or other issue that is breaking the circuit for the heater. Or it could be a junk sensor. Fewkin' Chinese bullshit. (Nothing against the Chinese themselves, but **** we get some cheap products from there...)

[bubbagumper6]

First things I would do:
Check the wiring to/from the sensor.
If you have a manual it should tell you how to actually check the sensor to see if it is what is actually wrong.

Just checked my service manual and it has some good info on checking the vehicle wiring for problems with the O2 sensor but nothing on how to check the actual sensor. It describes the voltage/continuity readings you should get on each of the pins on the connector that connects to the O2 sensor.

[audioatg]

2004 Hyundai Accent

Some forum post (on a different forum I found with google) said that sensor was the downstream one, I have no idea if it is or not...

What motor is in it. And are you sure that was the code that you got. p0036. I will look up the code tomorrow post later on that night.

But If this is the 2nd time you have replaced that sensor. I would check the wiring. Its most likely the o2 sensor. If its a heater code I would just go ahead and replace it. The aftermarket o2 sensors are not the greatest.

Also you might want to call up your local dealership and ask if there is any computer updates for that code.

[thevic24]

According to Alldata, p0036 is bank 1 sensor 1 heater control circuit

Ok, lets try this

SOURCE: Hyundai Tech Net Times Volume 13 Issue 5 2003
TITLE: Oxygen Sensors
APPLIES TO: 96 - 04 All
SERVICE TIP:
http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP1R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178282


An oxygen sensor measures the amount of oxygen present in the exhaust gas. The oxygen sensor ('element') is coated with a catalyst metal that produces a small voltage from 0 to 1.00 volt at temperatures in the range of 600°F (315°C) when exposed to oxygen. The "stoichiometric" air-fuel mixture for optimum fuel economy and emissions occurs at approximately 0.50 V. When the oxygen sensor output signal is above 0.50 V, the air-fuel mixture is considered rich and when the signal is under 0.50 V it is considered lean.
Hyundai OBD II engine management systems (1996 and later models) include two heated oxygen sensors (heated oxygen sensors allow the vehicle to go into closed loop in 20 to 30 seconds or less to reduce emissions):
^ The "upstream" (front) oxygen sensor is located in the exhaust stream before the catalytic converter. The front sensor provides feedback to the PCM that is used to identify if the air-fuel mixture supplied to the cylinders is rich or lean. Under normal operating conditions, the front oxygen sensor signal will fluctuate from 0 to 1.00 V. The front sensor signal should fluctuate, crossing the 0.50 V center about seven times in 5 seconds with the engine held at a steady 2500 rpm, when the vehicle is at operating temperature. ^ The "downstream" (rear) oxygen sensor is located after the catalytic converter in the exhaust stream. The rear sensor provides feedback to the PCM to 'fine tune' the air-fuel ratio and to monitor catalytic converter efficiency. The rear sensor signal will also fluctuate in the 0 to 1.00V range but the pattern is less predictable than for the front oxygen sensor because of its position in the exhaust system. Once the catalyst has reached operating temperature, the rear sensor signal should change very little, if at all. If the rear sensor signal fluctuates at approximately the frequency of the front sensor, it is an indication that the catalytic converter is not at operating temperature or is malfunctioning. Oxygen Sensor Diagnosis
A properly operating oxygen sensor may have unusual signal characteristics that are the result of other components. A malfunction of any of the following components may affect sensor signal characteristics:
^ Fuel injector(s) ^ Air flow sensor ^ Evaporative emission system ^ Intake air temperature sensor (http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOD%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857031) ^ Barometric pressure sensor ^ Engine coolant temperature sensor ^ Throttle position sensor (http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOD%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857616) ^ Intake system (vacuum) leaks ^ Low battery charge ^ Spark plugs The PCM does not monitor either oxygen sensor signal when the engine management system is in open loop or when the purge solenoid is operating.
If codes other than oxygen sensor codes are present, diagnose/repair these conditions BEFORE continuing with oxygen sensor diagnosis.
NOTE: A malfunctioning front oxygen sensor may cause fuel trim codes to set.
^ Several Diagnostic Trouble Codes use specific terminology to refer to sensor location. The illustration and key below explain the following terms: ^ Engine BANK Bank 1 is closer to the dash panel, (also referred to as RH or right hand). Bank 2 is closer to the radiator, (also referred to as LH or left hand). ^ UP Refers to Sensor 1 or "front sensor". It is located closer to the exhaust manifold and before the catalytic converter. ^ DOWN Refers to Sensor 2 or "rear sensor." It is located after the catalytic converter. http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178283


The following examples show how to interpret oxygen sensor terminology:
B1/S1 = Bank 1/Sensor 1 = Dash panel side, BEFORE the catalyst or "upstream"
B2/S2 = Bank 2/Sensor 2 = Radiator side, AFTER the catalyst or "downstream"
^ The Hi-Scan Pro testing procedure is provided in the following section. The Hi-Scan Pro test is a quick procedure that provides basic sensor information. Hi-Scan Pro Testing Procedure
Connect the Hi-Scan Pro and retrieve all diagnostic codes. Record the codes and freeze frame data (if available) for later reference.
1. A. Warm up the vehicle to operating temperature (for at least 3 minutes) B. Select vehicle, year, etc. C. Select "Engine" D. Select "Data" E. After OBD II data appears press "N" F. Select "Custom Data" G. Select "02-B1 S1" and "02-B1 S2" (front and rear oxygen sensors) and ENG RPM if no tachometer is available. H. Press "N" and the selected data will appear. 2. While holding the engine speed at 2500 rpm in Neutral or Park (with no load) observe the front and rear oxygen sensors for approximately one minute. The front oxygen sensor should fluctuate rapidly between 0.095 and 0.995 V. The voltage should read higher than 0.600 V several times and lower than 0.350 V several times. The voltage should never exceed 1.00 V when using the Hi-Scan Pro. If an Accent, Elantra or Tiburon front or rear oxygen sensor reads a fixed value of 0.425 V to 0.500 V, or a rear oxygen sensor reads a fixed value of 0.425 V to 0.500 V, or a Sonata reads a fixed value of 0.010 -0.080 V, check for an open/shorted oxygen sensor circuit or no output from the sensor.
The Hi-Scan Pro can also be used to check the sensors while the vehicle is being driven. An assistant is needed to perform this procedure. Use the Hi-Scan Pro as set up in the previous test procedure.
1. While driving in first gear, accelerate so the engine speed is near 4000 rpm. Quickly release the accelerator and observe the readings from both sensors. The sensors should read lean (in the range of 0.20 V down to 0 V) on the Hi-Scan Pro due to the fuel cutoff during deceleration. 2. While driving in first gear, accelerate hard and observe both sensors. The sensors should read rich (in the range of 0.60 V to 1.0 V) on the Hi-Scan Pro. Oxygen sensors can be monitored using HDS. The sensors can be observed using either "Custom Meters" or "Signal Wave Forms" on the HDS unit. It is preferable to use "signal Wave Forms" since the signal resolution is better with the engine operating at 2500 rpm, which is required for proper testing.
The HDS testing procedure requires a more involved set up but provides more detailed information about the sensors' performance. Refer to Technical Service Bulletin #97-36-004 for the testing procedure.
When the HDS is used to monitor oxygen sensor signals on 1996 and 1997 Accent & Elantra and 1997 Tiburon vehicles, a 0.70 V (0.71 V for Tiburon) signal offset is observed. This shifts the sensor readings 0.70 V (0.71 V for Tiburon) higher so the new signal range is 0.70 V to 1.70 V (0.71 V to 1.71 V for Tiburon). This shift is seen only when using the HDS machine because the sensor signal is read before it is processed (filtered) by the engine control module (ECM). (This offset is not present when using the Scan Tool.) The offset has no affect on the sensor signal appearance or frequency.
http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178284


http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178285

The oxygen sensor voltage offset (or bias voltage) observed when using the Hyundai Diagnostic System (HDS) was changed on 1998 Accent, Elantra & Tiburon from the value of previous model years. The oxygen sensor voltage offset is 0.27 volts for 1998 Elantra and Tiburon, and 0.30 volts for 1998 Accent.
Oxygen Sensor Diagnostic Trouble Codes
http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178286


The list below contains specific codes for Hyundai oxygen sensors and their explanations as needed.
In addition to further information found in shop manuals, several Technical Service Bulletins have been released regarding oxygen sensors. These can be found in the TSB bound manual or at the Hyundai Service website "Webtech Pro" section, (login required.
http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178287


http://www.alldatapro.com/alldata/PRO%7EV220516959%7EC40385%7ER0%7EOB0%7EP3R0H%7EN/0/101825161/106012456/106012457/110695802/34853741/34857029/100410262/100410263/34857572/34857599/120953799/113342736/115178288

[6.5LDiesel]

Ive learned from experience, NEVER buy a aftermarket O2 sensor, you WILL be replacing it...
Go right to the dealer..

[bubbagumper6]

Thanks for reviving a 2 month old thread

[6.5LDiesel]

People are waisting money on aftermaket O2 sensors

Ill let you waist your money :verymad:

[thevic24]

People are waisting money on aftermaket O2 sensors

Ill let you waist your money :verymad:
I have been running aftermarket 02 sensors in my truck now for over 4 years with no problems.
Funny thing is, the factory sensors are made by Bosch and are just under $200 for my app.
Same Bosch sensor(part # and all) is only $85 at Napa.....


Just like head lamp bulbs. The major dealer that I work for charges near $300 for a new HID bulb for a certain car. The factory bulb in the factory package is made by Phillips. The SAME EXACT bulb you can get at Napa for $70.......

[thevic24]

Here is an example of 02 sensors for a Lexus GS 460.

The factory sensor is made by Denso and the dealer wants $380 for one.
Here is the SAME sensor made by Denso for $170. And its the same exact part.
Denso/Oxygen Sensor (234-9068) | 2009 Lexus GS460 8 Cylinders 4.6L SFI DOHC | AutoZone.com (http://www.autozone.com/autozone/parts/Denso-Oxygen-Sensor/2009-Lexus-GS460/_/N-jty09Z9ixrp?counter=0&itemIdentifier=259913_199105_1784_98503)

[6.5LDiesel]

Here is an example of 02 sensors for a Lexus GS 460.

The factory sensor is made by Denso and the dealer wants $380 for one.
Here is the SAME sensor made by Denso for $170. And its the same exact part.
Denso/Oxygen Sensor (234-9068) | 2009 Lexus GS460 8 Cylinders 4.6L SFI DOHC | AutoZone.com (http://www.autozone.com/autozone/parts/Denso-Oxygen-Sensor/2009-Lexus-GS460/_/N-jty09Z9ixrp?counter=0&itemIdentifier=259913_199105_1784_98503)

This is not the case with every single vehicle on the road...:readytog:

[thevic24]

This is not the case with every single vehicle on the road...:readytog:
Just about it.....

Bosch makes the factory sensors for nearly every domestic car and Denso makes them for the Jap cars.
They are just re-badged for the different auto makers.

But I will agree with staying AWAY from the cheapies.!

Just call your dealer, see if they will give you the factory part # and do a cross reference.
To this day, I have never had a hard time finding factory components built by the component manufacture for far less than what dealer's charge for them.
(PS, I work for one of the world's largest car manufactures by the way.....)

[6.5LDiesel]

Just about every car I put in an aftermarket sensor in i had to do it again a year later

I just get it at the dealer, discount FTW

[thevic24]

Just about every car I put in an aftermarket sensor in i had to do it again a year later

I just get it at the dealer, discount FTW
Again, are you getting an "aftermarket" or an OEM part?

Hell, I only pay 5% over cost at my shop/dealer and in most cases I can still get the SAME part from Napa for less.
Keep in mind that an "aftermarket" will not have the same factory part # as the OEM factory part. A real OEM replacement part from an auto parts store will have the same factory part # on the part as will the same from the dealer, just in different packaging. You just have to look, search, cross reference for it.