Circuit Description
The powertrain control module (PCM) monitors the heated oxygen sensor
(HO2S) activity for 100 seconds. During this period, the PCM counts
the number of times that the HO2S switches form rich
to lean, and from lean to rich. A DTC P1133 or a DTC P1153
sets when the PCM determines that the HO2S did not switch
enough times.
A lean-to-rich switch is determined when the HO2S voltage changes from
less than 300 mV to more than 600 mV. A rich-to-lean switch
is determined when the HO2S voltage changes from more than 600 mV
to less than 300 mV. This diagnostic runs once per ignition
cycle.
Step
| Action
| Values
| Yes
| No
|
Schematic Reference:
Engine Controls Schematics
|
1
| Did you perform the Diagnostic System Check-Engine
Controls?
| --
| Go to
Step 2
| Go to
Diagnostic System Check - Engine Controls
|
2
|
ImportantIf any DTCs are set except DTC P1133 or P1153, refer
to those DTCs before proceeding with this diagnostic table.
- Install a scan tool.
- 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.
- Observe the diagnostic trouble code (DTC) Information with a scan
tool.
Did DTC P1133 or P1153 fail this ignition?
| --
| Go to
Step 3
| Go to
Intermittent Conditions
|
3
| Did both DTC P1133 and P1153 fail this ignition?
| --
| Go to
Step 8
| Go to
Step 4
|
4
|
- Inspect for an exhaust system leak. Refer to
Exhaust Leakage
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.
- Test the terminal tension at the HO2S and at the PCM.
- Inspect for damaged wiring.
Did you find and correct any conditions?
| --
| 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 that is 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.
- Observe the HO2S voltage with a scan tool.
Does the scan tool indicate a voltage that is below the specified value?
| 200 mV
| Go to
Step 13
| Go to
Step 9
|
8
|
ImportantDetermine 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
and/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.
- Measure the voltage from the HO2S low signal circuit to a battery
ground using the DMM. Refer to
Measuring Voltage
in Wiring Systems.
Does the DMM indicate a voltage near the specified value?
| 5 V
| Go to
Step 12
| Go to
Step 11
|
10
| Repair the HO2S high signal circuit for a short to ground or shorted
to a voltage. Refer to
Heated Oxygen Sensor (HO2S) Wiring Repairs
in Wiring Systems.
Did you complete the replacement?
| --
| Go to
Step 14
| --
|
11
| Repair the open in the HO2S low signal circuit, or repair the poor PCM
connections. Refer to
Heated Oxygen Sensor (HO2S) 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
Heated Oxygen Sensor (HO2S) Wiring Repairs
in Wiring Systems.
Did you complete the repair?
| --
| Go to
Step 14
| --
|
13
| Replace
the affected HO2S. Refer to
Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1
and/or
Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1
.
Did you complete the replacement?
| --
| Go to
Step 14
| --
|
14
|
- Use a scan tool in order to clear the DTCs.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Running the DTC
as specified in the supporting text.
Does the DTC run and pass?
| --
| Go to
Step 15
| Go to
Step 2
|
15
| With a scan tool, observe the stored
information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
| --
| Go to
Diagnostic Trouble Code (DTC) List
| System OK
|