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.
The system voltage is between 9-18 volts.
The PCM detects an incorrect circuit condition for the commanded state of the low side driver.
• | 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. |
• | 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. |
If the condition is intermittent, refer to Intermittent Conditions .
The numbers below refer to the step numbers on the diagnostic table.
This step isolates the condition. If all DTCs are set, this indicates that one of the heater low circuits are grounded. An internal HO2S condition can also cause all DTCs to set.
This step isolates the condition. If DTC P0036 is set without the other control circuit faults, the condition is present only in the HO2S bank 1 sensor 2 heater low control circuit.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |
Are DTCs P0030, P0036, P1031, and/or P1032 set? | Go to DTC P0030 | Go to Step 3 | |
Does DTC P0036 set? | Go to Step 4 | Go to Intermittent Conditions | |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 11 |
5 | With a test lamp connected to B+, probe the HO2S bank 1 sensor 2 heater low control circuit. Does the test lamp illuminate? | Go to Step 6 | Go to Step 7 |
6 |
Does the test lamp illuminate? | Go to Step 13 | Go to Step 15 |
7 |
Does the test lamp turn ON and OFF? | Go to Step 12 | Go to Step 8 |
8 | Test the HO2S bank 1 sensor 2 heater low control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 9 |
9 | Test the HO2S bank 1 sensor 2 heater low control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 10 |
10 | Test the HO2S bank 1 sensor 2 heater low control circuit for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 15 |
11 | Repair the open in the ignition supply voltage circuit to the HO2S bank 1 sensor 2. Did you complete the repair? | Go to Step 16 | -- |
12 | Test for poor connections at the HO2S bank 1 sensor 2 connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 14 |
13 | Repair the short to ground in the HO2S bank 1 sensor 2 heater low control circuit. Did you complete the repair? | Go to Step 16 | -- |
14 | Replace HO2S bank 1 sensor 2. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 . Did you complete the replacement? | Go to Step 16 | -- |
15 | Replace the PCM. Refer Powertrain Control Module Replacement . Did you complete the replacement? | Go to Step 16 | -- |
16 |
Does the DTC run and pass? | Go to Step 17 | Go to Step 4 |
17 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | System OK |