Threw this code today.Below is the info from the sticky in here on the cell.

p2237

monitor stradegy description:

A/F sensor not lean enough during fuel shutoff operation

primary malfunction signal and criteria:

assolute value of lambda control factor change from the point when the secondary conditions are met>

threshold value:

0.075

----------------
Autozones printout>The ecm detected the internal HO25 signal voltage is blah blah blah desired lambda out of spec.

Don't know the autozone printout means jack as far as descript,but it is generally saying o2 sensor.

This happened this morning in a nice cool weather,going wot from 3rd to around only 5k.

I really would like to hear thoughts on this besides bring it in to the shop.The car is driving ok,but feels kinda weak.I did'nt push it hard afterwards,just to check i can get proper boost and such.

 

hop this help good luck eather replace the O2sensor before you reprgram ECM do NOT GO TO Auto zone or any other places they don't have the right o2 sensor its a wideband heated O2 Sensor or WBHO2 sensor i've had this problem only dealer has the right O2 sensor

 

2008 Chevrolet Cobalt | Cobalt, G5 (VIN A) Service Manual | Document ID: 1957561
--------------------------------------------------------------------------------

DTC P2237, P2243, P2251, or P2626
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC P2237 : HO2S Pumping Current Control Circuit Sensor 1

DTC P2243 : HO2S Reference Voltage Circuit Sensor 1

DTC P2251 : HO2S Low Reference Circuit Sensor 1

DTC P2626 : HO2S Pumping Current Trim Circuit Sensor 1

Diagnostic Fault Information
Circuit
Short to Ground
Open/High Resistance
Short to Voltage

Heater Voltage Supply
P0030, P0130
P0030, P0053, P0130, P0135
--

Heater Low Control
P0031, P0130
P0030, P0053, P0135
P0032

Reference Voltage (Signal)
P0131
P0130, P2243
P0132

Low Reference (Ground)
P0130, P0136
P0130, P2251
P0132

Pump Current
P0130, P0131, P2237
P2237
P0132, P2237

Trim Current
P0130, P0131, P2626
P2626
P0132, P2626

Circuit/System Description
The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust stream more quickly and accurately than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine control module (ECM) supplies a signal voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell in order to maintain a constant signal voltage. The ECM monitors the voltage variation on the signal circuit and attempts to keep the voltage constant by increasing or decreasing the amount of current flow or reversing the direction of the current flow to the pumping cell. By measuring the direction and amount of current required to maintain the signal voltage, the ECM can determine the concentration of oxygen in the exhaust. The signal voltage is displayed as a lambda value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1. When the system is lean, the oxygen level will be high and the lambda value will be high, or more than 1. When the system is rich, the oxygen level is low and the lambda value will be low, or less than 1. The ECM uses this information to maintain the proper air/fuel ratio.

Conditions for Running the DTC
P2237
• The ignition voltage is between 10.7-18.1 volts.

• The engine is running.

• HO2S 1 voltage is between 1.48-1.52 volts.

• HO2S 1 heater is at operating temperature.

• HO2S 1 closed loop is active.

• The catalyst temperature is stable.

AND

• DTCs P0030, P0031, P0032, P0053, P0133, P0135 are not set.

• The ignition voltage is between 10.7-18.1 volts.

• The engine is running.

• The Lambda parameter is 0.97-1.03.

• HO2S 1 heater is at operating temperature.

• HO2S 1 Closed Loop is active.

AND

• DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, P0338 are not set.

• The ignition voltage is between 10.7-18.1 volts.

• The engine is running.

• HO2S 1 heater is at operating temperature.

• HO2S 1 Closed Loop is active.

• Deceleration fuel cutoff (DFCO) has been active for 3 seconds.

• DTC P2237 runs continuously when the above conditions are met for 2 seconds.

P2243
• DTCs P0030, P0031, P0032 are not set.

• The ignition voltage is between 10.7-18.1 volts.

• The engine is running.

• HO2S 1 heater is at operating temperature for at least 10 seconds.

• DTC P2243 runs continuously when the above conditions are met for 2 seconds.

P2251
• DTCs P0030, P0031, P0032 are not set.

• The ignition voltage is between 10.7-18.1 volts.

• The engine is running.

• The HO2S 1 heater temperature has been within the normal range for more than 20 seconds.

• HO2S 1 internal resistance is more than 950 ohms.

• The following are true for more than 20 seconds.

- The HO2S 1 heater is ready.

- The engine is running.

- The ignition voltage is more than 11 volts.

• DTC P2251 runs continuously when the above conditions are met.

P2626
• The ignition voltage is between 10.7-8.1 volts.

• The engine is running.

• Fuel cut-off is true.

• The estimated exhaust temperature is less than 780°C (1,436°F).

• The HO2S 1 heater is at operating temperature.

• DTC P2626 runs continuously when the above conditions are met for 2 seconds, or when the above conditions are met for 10 minutes if the fuel level is low.

Conditions for Setting the DTC
P2237
• The ECM detects that the pumping current circuit is open.

• DTC P2237 sets within 1 second when the above condition is met continuously, or within 10 seconds when the above condition is met cumulatively.

P2243
• The ECM detects that the HO2S 1 voltage is less than 0.2 volt or more than 4.7 volts.

• DTC P2243 sets within 1 second when the above condition is met continuously, or within 10 seconds when the above condition is met cumulatively.

P2251
• The ECM detects that the HO2S 1 reference ground circuit is open.

• DTC P2251 sets within 1 second when the above condition is met continuously, or within 10 seconds when the above condition is met cumulatively.

P2626
• The ECM detects that the HO2S 1 voltage is more than 4.81 volts.

• DTC P2626 sets within 1 second when the above condition is met continuously, or within 10 seconds when the above condition is met cumulatively.

Action Taken When the DTC Sets
DTCs P2237, P2243, P2251, and P2626 are Type B DTCs.

Conditions for Clearing the DTC
DTCs P2237, P2243, P2251, and P2626 are Type B DTCs.

Reference Information
Schematic Reference
Engine Controls Schematics

Connector End View Reference
Component Connector End Views

Electrical Information Reference

• Circuit Testing

• Connector Repairs

• Heated Oxygen Sensor Wiring Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
Control Module References for scan tool information

Circuit/System Verification
•Clear the DTCs with a scan tool.
•Operate the vehicle within the conditions for running and setting the DTC. The DTC should not set.
•Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

•Ignition OFF, disconnect the HO2S 1.
•Ignition ON, test for 2.9 volts between the HO2S 1 High Signal circuit terminal 6 and ground.
⇒ If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.

⇒ If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.

•Ignition ON, test for 2.5 volts between the HO2S 1 Low Signal circuit terminal 2 and ground.
⇒ If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.

⇒ If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.

•Ignition ON, test for 2.8 volts between the HO2S 1 Output Pump Current circuit terminal 1 and ground.
⇒ If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.

⇒ If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.

•Ignition ON, test for 2.8 volts between the HO2S 1 Input Pump Current circuit terminal 5 and ground.
⇒ If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.

⇒ If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.

•Ignition OFF, disconnect the ECM connector X1.
•Ignition OFF, test for infinite ohms between each HO2S 1 circuit terminal and all other HO2S 1 circuit terminals.
⇒ If less than the specified value, repair as necessary.

•If the ECM and all circuits test normal, replace the HO2S 1.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Heated Oxygen Sensor Replacement - Sensor 1

• Control Module References for ECM replacement, setup, and programming

 

^^^^^^ my version is smaller

 

fixed!

 

^^ niceeee

 

Sure appreciate the help,but a number of questions arise.Negrita,you mention NOt switching the sensor out with a non-stock pcm?I hope i misunderstood that,because i was tuned from 3 states away and have nothing to flash with,nor the stock tune. .??

What is involved with swapping out the sensor?Any soldering involved.I only have vague familiarity from seeing some pics of a stock downpipe.

Can i drive in this condition?It is my only vehicle.

Last,but not least,do you think my tune running rich contributed to this problem?I have a dyno graph in the dyno section.

 

sorry if u did not under stand what i was trying to say is that in the information i and Corvettespirt gave you if you go throw the list and every thing checks out ok with the O2sensor you have to flash the ECM to fix it but if the O2sensor is gone to ***** go to the dealer NOT Auto Zone or Discount auto parts they will sell you just a regular o2 sensor not the one our cars need cuz i had to replace one on a customers car

 

Update:car fixed itself,wth?day one code,next day cleared.Next day code,stayed on 2 full days,cleared itself and has not come back on.??This car is acting retarded.I can't make heads or tails of anything with no ability to monitor . I have plans for a retune,and will probably throw the new sensor in at that time i got direct from gm parts as i did'nt want the hassle as well as i could be at fault here in some way. Retightened all my piping and went back to stock plugs(actually,the new stock plugs) with a .032 gap.

 

Bringing this back form the dead.

I've been having the EXACT same thing happen to my SS. I am HPT Tuned for 20-21 PSI and have a Catless DP, Hot and Cold Charge Pipes from Dejon and a K&N Drop In filter. I failed my state emissions inspection due to my OBD ii Monitors were not ready. I've been performing my drive cycles to get them all ready but this code keeps coming up AND CLEARING ITSELF. I can't get anything done and I can't figure out what's going on.

My question to you is: Did you figure this out?

 

Just replace the O2 sensor and see if it fixed it.

 

I still have the new sensor and did not replace it.One of the plugs i replaced looked kinda funky too,.I have never thrown the code again since then.

 

This being the front O2 sensor, correct?

Maybe just buy yours if you're not doing anything with it? You got the correct wbho2?

Hopefully swapping these out solves the issue I.E. It's just a bad O2 Sensor.

 

acdelco part gm part#12589380.Paypal me 60 bucks and its yours

 

Are you saying you replaced the spark plugs? Just askin because I have the same code poppin up on mine