Check Engine Light Ses

[Black2003SS]

SES came on last night after a 45 minute drive in this cold weather. This is the second time in the last two weeks these have come on. I would think one cat might be bad if it was one bank, but being that its both banks sensor 2, I dont know what to make of it. And what does the immature status mean? Are the cats clogging up? This just started once the temperature started to get below freezing fyi. This is also the first winter I have had the blower on my truck.

 

 

PCM] P0137 - HO2S Circuit Low Voltage Bank 1 Sensor 2 (Immature)

[PCM] P0157 - HO2S Circuit Low Voltage Bank 2 Sensor 2 (SES) (History) (Immature)

 

Any ideas? In order to check the cats, they basically have to be cut out because of the way they were installed.

 

PS. I have 0* KR throughout the entire band at WOT and no misfires detected according to hpt.

Edited December 5, 2007 by Black2003SS (see edit history)

[Fireman31]

Info aquired from AllData............

 

DTC DESCRIPTORS

This diagnostic procedure supports the following DTCs:

 

 

DTC P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2

DTC P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2

 

CIRCUIT DESCRIPTION

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV . When the engine is first started, the PCM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream. If the PCM detects an HO2S voltage that stays below a specified value, DTC P0137 sets for HO2S bank 1 sensor 2, or DTC P0157 sets for HO2S bank 2 sensor 2.

 

 

CONDITIONS FOR RUNNING THE DTC

 

 

DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.

The Loop Status parameter is closed.

The Ignition 1 Signal parameter is between 10-18 volts .

The Fuel Alcohol content parameter is less than 90 percent .

The Fuel Tank Level Remaining parameter is greater than 10 percent .

The TP Indicated Angle parameter is between 3-70 percent more than the value observed at idle.

The above conditions are met for 2 seconds .

This diagnostic runs continuously when the above conditions are met.

 

CONDITIONS FOR SETTING THE DTC

The PCM detects that the affected HO2S voltage parameter is less than 80 mV for 200 seconds .

 

ACTION TAKEN WHEN THE DTC SETS

 

 

The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

 

CONDITIONS FOR CLEARING THE MIL/DTC

 

 

The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

Clear the MIL and the DTC with a scan tool.

 

Hope this helps you out

Edited December 5, 2007 by Fireman31 (see edit history)

[CoolBlueSS]

So, does this mean there is a lean condition, or bad sensors? Strange that it would all of a sudden run lean.

[Black2003SS]

The cold weather is a factor...so I am wondering if it is lean. It doesnt do it in 50* or 40* weather...just below 30* or so. It happened two weeks ago after driving 2 hours up north to go hunting and then it happened last night after about 45 minutes of freeway driving.

[CoolBlueSS]

True. Cold air is more dense. I would think it would compensate for that, though.

[misterp]

Info aquired from AllData

...

CONDITIONS FOR SETTING THE DTC

The PCM detects that the affected HO2S voltage parameter is less than 80 mV for 200 seconds.

...

First, these are the rear O2 sensors, the ones that monitor the cats. Second, I would see if something came unplugged because what the PCM is telling you is that the signal from the O2 sensors went missing for over 3 minutes. Another guess, if the cold weather is the culprit then what this may be telling you is that the heater in the both rear O2's has become weak Good thing is that this code is not the front O2s, those bastards are like $125 each to replace, the rears are considerably cheaper if in fact they are needing replacement.

 

Mr. P.

[Black2003SS]

Maybe I can just cut them out and turn them off...I'm going to get quote to do it today.