Chevrolet Trax: DTC P0131, P0132, P0134, P0137, P0138, OR P0140 (LUV)
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 P0131
HO2S Circuit Low Voltage Sensor 1
DTC P0132
HO2S Circuit High Voltage Sensor 1
DTC P0134
HO2S Circuit Insufficient Activity Sensor 1
DTC P0137
HO2S Circuit Low Voltage Sensor 2
DTC P0138
HO2S Circuit High Voltage Sensor 2
DTC P0140
HO2S Circuit Insufficient Activity Sensor 2
Diagnostic Fault Information
HO2S 1 or 2
Typical Scan Tool Data
HO2S 1 or 2
Circuit/System Description
The heated oxygen sensors (HO2S) are used for fuel control and catalyst
monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen content of the exhaust
stream. When the engine is
started, the control module operates in an open loop mode, ignoring the HO2S
signal voltage while calculating
the air to fuel ratio. While the engine runs, the HO2S heats up and begins to
generate a voltage within a range of
0-1 275 mV. Once sufficient HO2S voltage fluctuation is observed by the control
module, closed loop is
entered. The control module uses the HO2S voltage to determine the air to fuel
ratio. An HO2S voltage that
increases toward 1 000 mV indicates a rich fuel mixture. An HO2S voltage that
decreases toward 0 mV
indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to
operating conditions faster.
This allows the system to enter closed loop earlier and the control module to
calculate the air to fuel ratio
sooner
Conditions for Running the DTC
DTC P0131 or P0137
- DTCs P0068, P0106, P0107, P0108, P0121, P0122, P0123, P0222, P0223,
P0442, P0443, P0446, P0449,
P0451, P0452, P0453, P0454, P0455, P0496, P1101, P1516, P2101, P2119, P2135
and P2176 are not set.
- The ignition voltage is between 10-32 V.
- The fuel level is greater than 10%.
- The mass air flow (MAF) is between 2-60 g/s.
- The fuel composition is less than 87% ethanol.
- The fuel system is in Closed Loop.
- The vehicle is not decelerating.
- The DTC P0131 runs continuously when the above conditions are met for
greater than 3 s.
- The DTC P0137 runs continuously when the above conditions are met for
greater than 5 s.
DTC P0132 or P0138
- DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0121, P0122,
P0123, P0222, P0223, P0442,
P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1101, P1516,
P2101, P2119, P2135
and P2176 are not set.
- The ignition voltage is between 10-32 V.
- The fuel level is greater than 10%.
- The fuel composition is less than 87% ethanol.
- The fuel system is in Closed Loop.
- Engine run time is greater than 5 s.
- The vehicle is not decelerating.
- The DTC P0132 and P0138 run continuously when the above conditions are
met for greater than 3 s.
DTC P0134 or P0140
- DTCs P0068, P0101, P0102, P0103, P0121, P0122, P0123, P0222, P0223,
P1516, P2101, P2119, P2135
and P2176 are not set.
- The ignition voltage is between 10-32 V.
- HO2S heater warm up is finished.
- Engine run time is greater than 5 s.
- The engine has been operating for greater than 50 s.
- The fuel composition is less than 87% ethanol.
Conditions for Setting the DTC
P0131
The engine control module (ECM) detects that the heated oxygen sensor (HO2S)
voltage is less than 20 mV for
greater than 38 s.
P0137
The engine control module (ECM) detects that the heated oxygen sensor (HO2S)
is shorted to ground for
greater than 38 s.
P0132 or P0138
The ECM detects that the heated oxygen sensor (HO2S) voltage is greater than
1 050 mV for greater than 10 s.
P0134 or P0140
The ECM detects that the heated oxygen sensor (HO2S) voltage is greater than
1 700 mV for greater than 10 s.
Action Taken When the DTC Sets
DTCs P0131, P0132, P0134, P0137, P0138 and P0140 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0131, P0132, P0134, P0137, P0138 and P0140 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - TRAX
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) ,
Powertrain Diagnostic Trouble
Code (DTC) Type Definitions (2H0)
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON
- Verify no HO2S heater DTCs are set.
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Engine running.
- Verify the scan tool HO2S 1 or 2 parameters are between 50-1,050 mV.
- If not between 50-1,050 mV
Refer to Circuit/System Testing.
- 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.
- Verify the DTC does not set.
Refer to Circuit/System Testing.
- All OK.
Circuit/System Testing
- Ignition OFF and all vehicle systems OFF, disconnect the appropriate B52
Heated Oxygen Sensor
harness connector. It may take up to 2 minutes for all vehicle systems to
power down. Ignition ON.
- Test for 1.7-3.0 V between the high signal circuit terminal 4 and ground.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for infinite resistance between the high signal circuit terminal 4
and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the high signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K20 Engine Control Module.
- If greater than 3 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module. Ignition ON.
- Test for less than 1 V between the high signal circuit terminal 4 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- If between 1.7-3.0 V
- Verify the scan tool HO2S 1 or 2 parameter is between 1.7-3.0 V.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module. Ignition ON.
- Test for infinite resistance between the low signal circuit terminal 3
and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K20 Engine Control Module.
- If greater than 1.7 V
- Connect a 3 A fused jumper wire between the high signal circuit terminal
4 and the low signal circuit
terminal 3.
NOTE: The low signal circuit is tied to a pull-up circuit within
the engine control
module. A voltage of 0.0-1.1 V on the low signal circuit is normal.
- Verify the scan tool HO2S 1 or 2 parameter displays 0.0 V.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module. Ignition ON.
- Test for less than 2 ohms in the low signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms
- Test for less than 1 V between the low signal circuit terminal 3 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- If 0.0 V
- Verify none of the conditions listed below exist:
- Water intrusion in the B52 HO2S harness connector
- Low or high fuel system pressure-Refer to Fuel System Diagnosis (LUJ) ,
Fuel System Diagnosis
(LUV) .
- Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel
Diagnosis .
- Fuel saturation of the evaporative emission (EVAP) canister
- Exhaust leaks
- Engine vacuum leaks
- If any of the conditions exist
Repair as necessary
- If none of the conditions exist
- Test or replace the B52 Heated Oxygen Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic
procedure.
- Heated Oxygen Sensor Replacement - Sensor 1
- Heated Oxygen Sensor Replacement - Sensor 2
- Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset
after replacing an HO2S.
- Control Module References for ECM replacement, programming and setup
READ NEXT:
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.
Diag
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.
Diag
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.
Diag
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INTRODUCTION
You probably have several tools at your disposal to diagnose injector
circuits. But you might have questioned
"Is a lab scope necessary to do a thorough job, or will a set of noid lights and
a multifunction DVOM do just as
well?"
In the following text, we are going to look at what noi