Refer to Engine Control Schematics
HO2S
.
Circuit Description
The oxygen sensor heater is a device used to reduce the time that the sensor takes to go active. The bank 1 sensor 2 heater helps to maintain the sensor at the proper temperature for catalyst testing, and additional adjustments to fuel trim. The bank 1 sensor 2 heater receives power through a fused ignition circuit. The PCM turns the heater ON, and OFF using a low side driver (ODM) located within the PCM. The PCM monitors the low side driver for circuit conditions that are incorrect for the commanded state of the low side driver. If the PCM detects an incorrect circuit condition, DTC P0036 will set.
Conditions for Running the DTC
System voltage is between 9 and 18 volts.
Conditions for Setting the DTC
The PCM detects an incorrect circuit condition for the commanded state of the low side driver.
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
If the condition is intermittent, refer to Intermittent Conditions .
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check ? | -- | Go to Step 2 | |
2 |
Is the test lamp ON? | -- | Go to Step 3 | Go to Step 10 |
3 | Connect test lamp between chassis ground and the HO2S Bank 1 Sensor 2 heater low circuit. Is the test lamp ON? | -- | Go to Step 11 | Go to Step 4 |
4 |
Is the test lamp ON? | -- | Go to Step 5 | Go to Step 6 |
5 | Locate and repair the short to ground in the HO2S Bank 1 Sensor 2 heater low circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 14 | -- |
6 |
Is the test lamp ON? | -- | Go to Step 7 | Go to Step 8 |
7 | Test for poor terminal connections at the HO2S Bank 1 Sensor 2 connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If the condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
8 | Test for an open in the HO2S Bank 1 Sensor 2 heater low circuit. If either condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct either condition? | -- | Go to Step 14 | Go to Step 9 |
9 | Test for poor terminal connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If the conditions is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
10 | Locate and repair the open ignition feed circuit to HO2S Bank 1 Sensor 2. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 14 | -- |
11 | Locate and repair the short to voltage in the HO2S Bank 1 Sensor 2 heater low circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 14 | -- |
12 | Replace the HO2S Bank 1 Sensor 2. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 . Is the action complete? | -- | Go to Step 14 | -- |
13 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 14 | -- |
14 |
Does the scan tool indicate that DTC P0036 passed? | -- | System OK | Go to Step 2 |
