Diagnostic Instructions
DTC Descriptors
DTC P0135: HO2S Heater Performance Sensor 1
DTC P0141: HO2S Heater Performance Sensor 2
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Ignition Voltage Supply
| P0030, P0031, P0036, P0037
| P0134, P0135, P0140,
| --
| P0135, P0141
|
HO2S Sensor 1 Heater Control
| P0031
| P0030, P0134
| P0032
| P0135
|
HO2S Sensor 2 Heater Control
| P0037
| P0036, P0140
| P0038
| P0141
|
Circuit Description
The heated oxygen sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage
is supplied directly to the sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are cold. This prevents the possibility of thermal shock to the sensor, from condensation
build-up on the sensor, by controlling the sensor's rate of heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature, the ECM may modulate the heater control circuit to ground
to maintain a desired temperature. The ECM controls the heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled up to voltage. The ECM can determine if the control circuit
is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.
Conditions for Running the DTC
P0135
| • | Before the ECM can report DTC P0135 failed, P0030, P0031, and P0032 must run and pass. |
| • | DTC P0130, P0131, P0132, or P0134 is not set. |
| • | The engine is operating. |
| • | The ignition voltage is 10-18 volts. |
| • | The intake air temperature (IAT) is greater than -30°C (-22°F). |
| • | After the previous ignition cycle the engine OFF time was greater than 2 minutes. |
| • | The calculated exhaust temperature is less than 524°C (975°F). |
| • | The engine is not in decel fuel cut-off (DFCO). |
| • | The HO2S 1 is at operating temperature for greater than 10 seconds. |
| • | The internal HO2S 1 resistance is less than 10,000 Ω. |
| • | DTCs P0135 runs continuously once the above conditions are met for approximately 100 seconds. |
P0141
| • | Before the ECM can report DTC P0135 and P0141 failed, DTCs P0036, P0037, and P0038 must run and pass. |
| • | DTCs P0137, P0138, or P0140 are not set. |
| • | The engine is operating. |
| • | The ignition voltage is 10-18 volts. |
| • | The intake air temperature (IAT) is greater than -30°C (-22°F). |
| • | After the previous ignition cycle the engine OFF time was greater than 0 seconds. |
| • | The calculated exhaust temperature is 360-500°C (680-932°F). |
| • | The engine is not in decel fuel cut-off (DFCO). |
| • | The internal HO2S 2 resistance is less than 10,000 Ω. |
| • | The HO2S 2 heater is enabled for greater than 120 seconds. |
| • | DTCs P0135 and P0141 run continuously once the above conditions are met for approximately 100 seconds. |
Conditions for Setting the DTC
The ECM detects that the internal resistance of an HO2S 1 or HO2S 2 heater is not within the expected range.
Action Taken When the DTC Sets
DTCs P0135 and P0141 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0135 and P0141 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Note: It may take up to 8 minutes for the DTC to set.
- With the engine at normal operating temperature, operate the engine above 1,200 RPM for 2 minutes and then allow the engine to idle. DTCs P0135 or P0141 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.
- Ignition ON, test for B+ on the HO2S ignition circuit terminal 1 of the HO2S harness connector.
| ⇒ | If less than the specified value, repair the ignition voltage circuit of the HO2S heater for a short to ground or an open/high resistance. |
- Ignition OFF, connect a test lamp between the heater control circuit terminal 2 and B+. The test light should not illuminate.
| ⇒ | If test lamp illuminates, test the heater control circuit for a short to ground. If the circuit/connections test normal, replace the K20 ECM. |
- Idle the engine, and verify the test lamp illuminates or flashes.
| ⇒ | If the test lamp is always OFF, test the control circuit terminal 2 for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM. |
Note: The control circuit for the HO2S heater is pulled-up to voltage within the ECM, 2.0-3.0 V on the control circuit is normal.
- Ignition ON, test for 2.0-3.0 V between the control circuit terminal 2 and ground.
| ⇒ | If not within the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the K20 ECM. |
- If all circuits/connections test normal, test or replace the B52 HO2S.
Component Testing
- Ignition OFF, disconnect the harness connector at the appropriate B52 heated oxygen sensor (HO2S) sensor.
- Test for 5-25 Ω between the control terminal 2 and the ignition terminal 1 of the B52 heated oxygen sensor (HO2S) sensor.
| ⇒ | If not within the specified range, replace the B52 HO2S sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
