During a recent cruise, the Ck Eng light illuminated. Went through the codes and this one popped up...O2 sensor problem, but where should I start to fix?

Thanks,
Dan

 

This is a little long, but here is the flow chart from GM's Service info.

Document ID# 851400
2003 Chevrolet Corvette


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DTC P0133 or P0153
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.

This diagnostic will only run once per ignition cycle. The PCM monitors the rich-to-lean and lean-to-rich transition time. A transition is defined as, the HO2S voltage changes from above 600 mV to below 300 mV or from below 300 mV to above 600 mV. If the PCM detects that the transition time is too long, DTC P0133 or P0153 sets.

Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.
The ECT sensor parameter is more than 50°C (122°F).
The Ignition 1 Signal parameter is between 9-18 volts.
The Loop Status Parameter is Closed.
The Engine Speed Parameter is between 1,000-2,300 RPM.
The MAF sensor parameter is between 18-50 g/s.
The EVAP purge solenoid command parameter is more than 0 percent.
The Engine Run Time Parameter is more than 160 seconds.
The TP indicated angle parameter is 5 percent more than the value observed at idle.
The fuel level parameter is more than 10 percent.
The above conditions are met for 60 seconds.
Conditions for Setting the DTC
The lean to rich response, defined as less than 300 mV to more than 600 mV, average time is more than a calibrated amount.
The rich to lean response, defined as more than 600 mV to less than 300 mV, average time is more than a calibrated amount.
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.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

When DTCs P0133 and P0153 are set at the same time a fuel contamination concern is present.

An exhaust leak 6-12 inches away from the HO2S can cause a DTC to set.

This step tests the integrity of the signal circuit to the PCM.

This step tests the integrity of the signal circuit to the PCM.

Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2

Important
If any DTCs are set except DTC P0133 or P0153, refer to those DTCs before proceeding with this diagnostic table.


Install a scan tool.
Start the engine and idle the engine at the normal operating temperature.
Operate the vehicle within the parameters specified under Conditions for Running the DTC in the supporting text.
With the scan tool observe the DTC Information.
Did DTC P0133 or P0153 fail this ignition?
--
Go to Step 3
Go to Intermittent Conditions

3
Did both DTC P0133 and P0153 fail this ignition?
--
Go to Step 8
Go to Step 4

4
Test for an exhaust system leak. Refer to Exhaust System Description in Engine Exhaust.
If you find an exhaust leak, repair the exhaust leak as necessary.
Did you find and correct the condition?
--
Go to Step 14
Go to Step 5

5
Inspect for the following conditions:

Ensure that the HO2S is securely installed.
Inspect for corrosion on the terminals.
Inspect the terminal tension at the HO2S and at the PCM.
Inspect for damaged wiring.
Did you find and correct the condition?
--
Go to Step 14
Go to Step 6

6
Disconnect the HO2S.
Jumper the HO2S low signal circuit on the PCM side to a known good ground.
Observe the HO2S voltage on the scan tool.
Does the scan tool indicate a voltage within the specified range?
350-550 mV
Go to Step 7
Go to Step 10

7
Jumper the HO2S high and low signal circuits on the PCM side to a battery ground.
Use the scan tool in order to monitor the HO2S voltage.
Is the voltage less than the specified value?
200 mV
Go to Step 13
Go to Step 9

8

Important
Determine and correct the cause of the contamination before replacing a sensor. Inspect for the following conditions:

Fuel contamination
Use of an improper RTV sealant
Engine oil or coolant consumption

Replace the affected Heated Oxygen sensor. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .

Did you complete the replacement?
--
Go to Step 14
--

9
Remove the jumper wire from the HO2S low signal circuit.
Use the DMM in order to measure the voltage from the HO2S low signal circuit to a battery ground.
Is the voltage near the specified value?
5 V
Go to Step 12
Go to Step 11

10
Repair the high signal circuit for a short to ground or for a short to voltage. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 14
--

11
Repair the open HO2S low signal circuit, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 14
--

12
Repair the HO2S high signal circuit for an open, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 14
--

13
Replace the HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .

Did you complete the replacement?
--
Go to Step 14
--

14
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
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.
Did the DTC fail this ignition?
--
Go to Step 2
Go to Step 15

15
Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK



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Document ID# 851400
2003 Chevrolet Corvette