Emissions - OBD O2 Sensor Heater DTC Confirmation
FORENZASection Title: Engine
TSB No. TS 25 10190
Division: Automotive
Category: Technical
SUBJECT:
ON-BOARD DIAGNOSTIC (OBD) SYSTEM DTC CONFIRMATION
PROCEDURE: OXYGEN SENSOR HEATER
MODEL(S):
FORENZA, FORENZA WAGON, RENO (RQ420)
YEAR:
2004~2008
CONDITION:
Diagnostic readiness status is "Incomplete".
CAUSE:
Requirements have not been met under the specific vehicle conditions and procedures.
CORRECTION:
Please follow the attached DTC Confirmation Procedures outlining what is required for the readiness status to complete.
Note:
The following specifications and procedures do not relate to any specific repair or failure state, they represent the minimum requirements that the system must experience during the self diagnostic sequence for this specific component.
The conditions and procedures are exclusive to the model(s) listed above, and apply only to setting the readiness status of the Oxygen Sensor Heater to the "YES" condition.
Due to changes to Emission Regulations and/or the vehicles emission control system, be sure to use the procedure that applies to your model year vehicle, as they may vary.
> For 2004 and 2005 model years use: AA. MY04~MY05
> For 2006 - 2008 model years use: BB. MY06~MY08
AA. MY04~MY05:
Oxygen Sensor Heater
Description
The purpose of this procedure is to satisfy the enable criteria necessary in order to execute the Heated Oxygen Sensor (HO2S) Heater System diagnostic. Ensure the vehicle meets the requirements listed in Conditions for Running before performing this test. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION
PROCEDURE:
> Ignition voltage> 10 volts
> Runtime > 200 seconds
Diagnostic Aids
> The H025 Heater Tests will normally run within the 2 minutes allotted in the procedure. If there is an indeterminate condition, the test may take up to 8 minutes on some vehicles before a decision of pass or fail is made. If the test does not update within the allotted time, continue operation within the enable conditions until the readiness status updates to YES. If the readiness status does not update to YES, it may have failed or aborted due to the loss of enabling conditions. Extremely high ambient temperatures may prevent the H025 Heater Test from initiating.
> The readiness status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the readiness status will update to YES. If a test for a specific system has failed, the readiness status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the scan tool will output the DTC and malfunction indicator lamp (MIL) status.
> The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the readiness status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down. The readiness status will update only when the DTC fails the second time, or all of the tests pass.
> If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and review the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in the engine load, such as a cooling fan or an A/C compressor clutch turning on, may cause the test to abort.
> If a diagnostic test is difficult to run, observe the scan tool display while maintaining the necessary enable conditions until the readiness status updates to YES.
Step Action (Detecting Condition)
1. Connect scan tool to DLC with ignition switch OFF
2. Start engine.
3. Idle vehicle for 2 minutes.
4. Check DTC by using scan tool.
BB. MY06~MY08:
Oxygen Sensor Heater
Description
The purpose of this procedure is to satisfy the enable criteria necessary in order to execute the Heated Oxygen Sensor (HO2S) Heater System diagnostics. Ensure the vehicle meets the requirements listed in Conditions for Running before performing this test. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION
PROCEDURE:
> Ignition voltage > 10 volts
> Runtime > 60 seconds
Diagnostic Aids
> The H025 Heater Tests will normally run within the 2 minutes allotted in the procedure. If there is an indeterminate condition, the test may take up to 8 minutes on some vehicles before a decision of pass or fail is made. If the test does not update within the allotted time, continue operation within the enable conditions until the test updates to YES. If the test does not update to YES, it may have failed or aborted due to the loss of enabling conditions. Extremely high ambient temperatures may prevent the H025 Heater Test from initiating.
> The readiness status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the readiness status will update to YES. If a test for a specific system has failed, the readiness status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the scan tool will output the DTC and malfunction indicator lamp (MIL) status. The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the readiness status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down. The readiness status will update only when the DTC fails the second time, or all of the tests pass.
> If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and review the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in the engine load, such as a cooling fan or an A/C compressor clutch turning on, may cause the test to abort.
> If a diagnostic test is difficult to run, observe the scan tool display while maintaining the necessary enable conditions until the readiness status updates to YES.
Step Action
1. Connect scan tool to DLC with ignition switch OFF
2. Start engine.
3. Idle vehicle for 2 minutes.
4. Check DTC by using scan tool.