1996 Sonoma 4.3L - O2 P0133 code

[quadordie]

SES light came on, repeatidly (at least 2 resets). I have a code PO133 - O2 circuit Slow Response Bank 1 Sensor 1 on my 1996 Sonoma with 47,000 miles 4.3L. Anybody know which O2 sensor is Sensor 1, pretty sure I need to replace it and should be good to go!

Thanks in advance

By the way, good website I found listing Codes http://patriot.net/~bmcgin/canreader.html

[rat]

I think that is on the side of the #1 cyl(drivers side). It should be the one up near the manifold.

[Sparky2263]

Yup, drivers side, upstream.

[quadordie]

Replaced Driver's side O2 sensor just below manifold (before CAT convertor) and SES light came back on (reset by undoing neg ground for 5 minutes). What gives? Anybody know? Haven't run the code yet.

[Sparky2263]

Run the code.

[Sparky2263]

Here's a description straight outta' the book.

Circuit Description
The Vehicle Control Module (VCM (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/101367125)) supplies a voltage of approximately 0.45 volt (450 mV) between the HO2S High and the HO2S Low circuits.

Important: If a 10 megaohm digital voltmeter measures this voltage, the voltage may read as low as 0.32 volt. The Heated Oxygen Sensor (HO2S) varies the voltage within a range of about 1.0 volt (1000 mV) if the exhaust is rich to as low as 0.1 volt (100 mV) if the exhaust is lean.

The VCM (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/101367125) monitors the HO2S activity for 100 seconds after the Closed Loop. During the monitor period, the VCM counts the number of times the HO2S switches from rich to lead and from lean to rich and adds the amount of time the sensor took to complete all the switches. With this information, the VCM determines an average time. If the average time to switch is too slow, a DTC P0133 sets.

When the HO2S temperature measures below 360°C (600°F), the sensor will not produce any voltage. The sensor will behave like an open circuit. This will result in an Open Loop operation.

The HO2S heater provides for a faster sensor warm-up which allows the sensor to become active in a shorter period of time. This allows the sensor to remain active during a long extended idle. The DTC P0133 determines if the HO2S is functioning properly by checking the response time of the sensor. This DTC is a type B DTC.

Conditions For Setting The DTC
The Following Conditions will set the DTC:



No Throttle Position (TP) sensor DTCs.
No Evaporation Emission (EVAP (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857699/34872077)) DTCs.
No Intake Air Temperature (IAT (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/34857031)) sensor DTCs.
No Manifold Absolute Pressure (MAP (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/101367131)) sensor DTCs.
No Engine Coolant Temperature (ECT) sensor DTCs.
No Mass Air Flow (MAF (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/56191599)) sensor DTCs.
No intrusive test in progress.
No device controls are active.
The system voltage measures at least 9.0 volts.
The HO2S (Bank 1, Sensor 1) average transition time from lean to rich is greater than 85 milliseconds.
The HO2S (Bank 1, Sensor 1) average transition time from rich to lean is greater than 85 milliseconds.
Response Test Enable




The DTCs P0131, P0132, P0134 and P0135 are not present.
A Closed Loop runs.
The ECT is greater than 57°C.
The engine run time is greater than 75 seconds.
The MAF (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/56191599) is at least 15 grams per second but less than 55 grams per second.
Engine speed is at least 1100 RPM but less than 3000 RPM.
The EVAP canister purge duty cycle is greater than 0%.
The above condition is present for more than 2 seconds.
The Bank 1 Sensor 1 HO2S voltage remains between 0.300 volt and 0.600 volt.
Action Taken When DTC Sets
The VCM (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/101367125) turns on the Malfunction Indicator Lamp (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/34857480) (MIL) after the second test failure.

Conditions For Clearing The MIL (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/34857480)/DTC
The VCM (http://www.motoralldata.com/alldata/MOTOR~V25951041~C23532~R0~OD~N/0/41746574/42420501/42420544/42420547/34853741/34857029/34857030/101367125) turns the MIL off after 3 consecutive driving trips without a fault condition present. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 40°F from the start-up coolant temperature and the engine coolant temperature exceeds 160°F during that same ignition cycle) or the scan tool clearing feature has been used.

Diagnostic Aids
Check the HO2S heater operation.

NOTE : Never solder the HO2S wires. For proper wire and connector repairs, refer to Diagrams.

Test Description
The number below refers to the step number on the diagnostic table.




This step checks for physical damage to the engine components and the converter.

[quadordie]

Sweet info, going to try a couple tricks that worked on other vehicles. First I am going to scan it to verify same code. Then clean MAF with brake cleaner (could be dirty and causing goofy results), clean throttle body with Carb cleaner, after that, go to a friends with Snap on scanner and read results of the sensors. Hopefully this thing will get figured out, trying to sell it and no one wants to buy a vehicle with the MIL light on.

Thanks again,
Quadordie

[quadordie]

Here is some additional info on the 1996 GMC Sonoma, 8th digit is X on VIN, I bought truck about 2 weeks ago, it was a city truck and probably sat for at least a month before I bought it. I drove it 300 miles home and the SES came on about 180 miles into the trip. It went off for about 50-80 miles and then came back on. has been on ever since. Truck seems to run fine, idles smooth and accelerates as you would expect. Have never checked gas mileage.

[quadordie]

The code was PO113 - Air Temp Sensor Circuit. Turns out I had not plugged it back in after disconnecting it and cleaning with Carb Cleaner (per another peice of info from mechanic). All codes have been cleared and No SES light. Seems to be OK so far.

[Sparky2263]

Excellent!

[KRUZER1]

haha right on, glad to hear it was simple.